Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 06/02/12
AREA FORECAST DISCUSSION
NWS DENVER CO
832 PM MDT FRI JUN 1 2012
.UPDATE...EVENING CONVECTION HAS COME TO AN END IN ALL BUT THE
FOOTHILLS AND SOUTH PARK. THESE WILL BE ENDING IN THE NEXT HOUR OR
SO AS AIRMASS STABILIZES. OTHERWISE LOOK FOR CLEARING SKIES FOR
THE REST OF THE NIGHT.
&&
.AVIATION...ANY THREAT OF SHOWERS/STORMS HAS ENDED THIS EVENING.
WINDS WILL GRADUALLY TRANSITION TO MORE SOUTHERLY DIRECTION
THROUGH 06Z-07Z...ALTHOUGH A WEAK DENVER CYCLONE DEVELOPING
OVERNIGHT COULD BRING VARIABLE A MORE NORTHWESTERLY COMPONENT BY
10Z-13Z.
&&
.PREV DISCUSSION... /ISSUED 236 PM MDT FRI JUN 1 2012/
SHORT TERM...THE UPPER LEVEL RIDGE WILL SLOWLY SHIFT EAST ACROSS
THE GREAT BASIN TONIGHT AND SATURDAY. NORTHWEST FLOW TODAY WILL
BECOME MORE WESTERLY AS THE RIDGES NEARS. CAPES ARE UP TO 300 J/KG
OVER THE HIGHER TERRAIN. RADAR SHOWING SOME WEAK CONVECTION ALONG
THE FRONT RANGE...NOT SURE IF ANY RAIN IS REACHING THE GROUND YET.
THE HRRR SHOWS THIS WEAK CONVECTION CONTINUING THROUGH EARLY
EVENING. WILL HAVE LOW POPS THROUGH 04Z AND THEN NO MENTION OF
WEATHER UNTIL SATURDAY.
AIRMASS TO WARM A LITTLE MORE ON SATURDAY WITH MOST LOCATIONS OVER
NORTHEAST COLORADO WELL INTO THE 80S. MOISTURE WILL INCREASE SLIGHT
WITH DEW POINTS HANGING IN THE UPPER 30S TO 40S FOR MOST OF THE DAY.
CAPES WILL INCREASE TO 500-1000 J/KG SATURDAY. THIS COMBINED WITH A
SHORT WAVE TROUGH PASSING THROUGH THE RIDGE WILL PRODUCE ISOLATE TO
SCATTERED THUNDERSTORMS. THE BEST CHANCE WILL BE OVER THE EASTERN
PLAINS WHERE THE MOISTURE WILL BE GREATEST. WIND SHEAR WILL NOT BE
THAT GREAT...SO THE THREAT FOR SEVERE STORMS WILL BE LOW. THOUGH A
FEW MARGINALLY SEVERE STORMS CAN NOT BE RULED OUT.
LONG TERM...NO SIGNIFICANT CHANGES PLANNED. IT WILL BE WARMER
AND DRIER ON SUNDAY AND MONDAY AS A RIDGE OF HIGH PRESSURE BUILDS
OVER THE WEST. ALTHOUGH TEMPERATURES WILL BE ABOVE NORMAL
..ELEVATING THE FIRE DANGER...THE WINDS AT THE SURFACE AND ALOFT
WILL BE WEAK WITH JUST A SLIGHT CHANCE OF THUNDERSTORMS IN THE
AFTERNOON AND EVENING. THE RIDGE AXIS WILL SHIFT OVER THE
SOUTHERN/CENTRAL PLAINS FOR TUESDAY AND WEDNESDAY WITH A WEAK
SOUTHERLY FLOW OVER COLORADO. THE SYNOPTIC PATTERN LOOKS LIKE A
MONSOON SETUP FOR A SHORT TIME BUT WITH LIMITED MOISTURE
AVAILABLE. THE MDLS SUGGEST SOME POTENTIAL FOR AFTN AND EVENING
THUNDERSTORMS WITH SFC DEWPOINTS IN THE MID 40S TO LOWER 50S OVER
THE NERN PLAINS OF COLORADO. ALL OF THIS ALREADY ADDRESSED IN THE
GRIDS SO NO ADJUSTMENTS AT THIS TIME. THE FLOW ALOFT MAY INCREASE
BY WEDNESDAY AS AN UPPER LEVEL TROUGH PASSES TO THE WEST AND NORTH
OF THE STATE ON WEDNESDAY SO MAYBE SOME MORE WIND BY MIDWEEK.
AVIATION...THERE WILL BE A SLIGHT CHANCE FOR A WEAK SHOWER OR
THUNDERSTORM THROUGH 03Z. MAIN THREAT WILL BE GUSTY OUTFLOW WINDS TO
30 KNOTS. OUTSIDE OF OUTFLOW WINDS...SURFACE WINDS WILL GENERALLY BE
OUT OF THE EAST THROUGH 03Z AND THEN SHIFT TO THE SOUTH BY 06Z. ON
SATURDAY...THERE WILL BE A BETTER CHANCE FOR AFTERNOON
THUNDERSTORMS.
HYDROLOGY...THERE WILL BE A SLIGHT CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. IF ANY STORMS FORM...THEY WILL BE SHORT LIVED AND
PRODUCE LIGHT RAINFALL. SCATTERED THUNDERSTORMS WILL BE POSSIBLE
SATURDAY. BRIEF HEAVY RAIN WILL BE POSSIBLE...BUT WITH STORM
MOVEMENTS AROUND 20-25 MPH...ANY HEAVY RAIN SHOULD BE SHORT IN
DURATION.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....COOPER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
338 PM MDT THU MAY 31 2012
.SHORT TERM...
(TONIGHT AND TOMORROW)
CURRENTLY...
AS OF 2 PM...ISOLATED SHOWERS WERE DEVELOPING OVER THE SANGRES AND
SAN JUAN MTNS. OTHERWISE...SKIES WERE MOSTLY CLEAR OVER THE
REMAINDER OF THE REGION. TEMPS OVER THE REGION WERE ON THE COOLER
SIDE...WITH THE SAN LUIS VALLEY AND THE PLAINS IN THE 70-75 RANGE. A
WEAK DIURNAL WIND REGIME WAS DEVELOPING OVER THE AREA.
REST OF AFTERNOON/EVENING...
BEST CHANCE OF ISOLD TSRA ACTIVITY WILL BE OVER THE MTNS...WITH THE
BEST CHANCE OF SOME STRONGER STORMS OVER THE S SANGRES AND RATON
MESA REGION. BOTH LOCAL WRF AND HRRR ARE SHOWING HEAVIER QPF
BREAKING OUT THESE REGIONS DURING THIS TIME PD. ONCE ACTIVITY GETS
GOING...IT SHOULD MOVE IN A SE DIRECTION GIVEN THE NW FLOW ALOFT.
MARGINAL SVR HAIL AND SOME STRONGER GUSTS COULD OCCUR WITH STORMS
GIVEN THE SHEAR IN PLACE.
ONE ISSUE I AM NOT TOO CONFIDENT ABOUT IS SOME CONVECTION MOVING
ACROSS THE FAR E PLAINS THIS EVENING. LATEST HRRR IS HINTING AT THIS
BUT OTHER GUIDANCE KEEPS THE PLAINS ON THE DRY SIDE. FOR NOW WILL
KEEP SILENT POPS OVER THIS REGION AND ALLOW EVENING SHIFT TO ADJUST
POPS IF WARRANTED.
TONIGHT...
DRY CONDITIONS ANTICIPATED DURING THE EARLY MORNING HOURS.
SIMULATIONS DO SHOW A MCS DEVELOPING OVER W NE/SW NE MOVING EAST
LATE TONIGHT...BUT BELIEVE THIS ACTIVITY SHOULD REMAIN OUT OF OUR
CWA AS IT MOVES SE ACROSS W KS.
TOMORROW...
COOL FRONT WILL MOVE ACROSS THE REGION TOMORROW MORNING ASSOCIATED
WITH AFORMENTIONED MCS. WE COULD SEE SOME GUSTY N WINDS...25-30 MPH
IN THE MORNING...OVER THE PLAINS AND POSSIBLY E SXNS OF EL PASO
COUNTY. WINDS WILL QUICKLY TRANSISTION TO AN UPSLOPE COMPONENT...AND
BEST CHANCE OF POPS ONCE AGAIN WILL BE OVER E FACING SLOPES OF E
MTNS. DEPENDING IF THE FRONT STALLS ALONG THE CO/NM BORDER...WE MAY
SEE A BETTER CHANCE OF POPS ALONG THE RATON MESA REGION LATER IN THE
DAY. TEMPS OVERALL SHOULD BE ABOUT 4-8F WARMER THAN TODAY.
.LONG TERM...
(FRIDAY NIGHT THROUGH NEXT THURSDAY)
ISOLATED TSRA FRI EVENING SHOULD SHIFT SOUTHEAST INTO THE TEXAS
PANHANDLE OVERNIGHT...AS DEEPER MOISTURE REMAINS JUST SOUTH OF THE
AREA. ON SAT...NICE SOUTHEAST UPSLOPE FLOW DEVELOPS OVER THE
PLAINS...WHICH SHOULD ADVECT A MORE MOIST AND UNSTABLE AIR MASS
INTO THE AREA BY AFTERNOON. MODEL PERFORMANCE THE PAST COUPLE DAYS
SUGGESTS GFS DEWPOINTS APPROACHING 60F ARE SLIGHTLY
OVERDONE...THOUGH EVEN GOING WITH LOWER NAM NUMBERS IN THE 40S TO
50S YIELDS CAPES WELL ABOVE 1000 J/KG ACROSS MUCH OF THE EASTERN
PLAINS EAST OF I-25 BY LATE IN THE DAY. STILL APPEARS WEAK WAVE
WILL WIGGLE EAST THROUGH THE RIDGE AS WELL...ENHANCING UPWARD
MOTION OVER THE AREA INTO SAT EVENING. SOME THREAT OF A SEVERE
STORM OR TWO OVER THE PLAINS NEAR THE KS BORDER...WHERE DEEPER
INSTABILITY AND 0-6KM SHEAR OF 30-40 KNOTS COINCIDE. THUS
CONTINUED TO NUDGE POPS UPWARD SAT AFTERNOON AND EVENING...WITH AT
LEAST A SCATTERED MENTION IN MOST EASTERN MOUNTAIN AND PLAINS
ZONES. SUNDAY STILL LOOKS DRIER AS DEEPER MOISTURE IS PUSHED
EAST...THOUGH LATEST MODELS KEEP SURFACE DEWPOINTS HIGHER THAN
PREVIOUS RUNS...WHICH MAY LEAD TO SLIGHTLY BETTER CONVECTIVE
COVERAGE THAN EARLIER THOUGHT. STILL DON`T SEE MUCH MORE THAN
ISOLATED TSRA OVER MAINLY THE MOUNTAINS...ESPECIALLY AS STEERING
FLOW IS WEAK AS UPPER RIDGE IS OVERHEAD. SHOULD SEE MAX TEMPS STAY
WARM BOTH SAT AND SUN AS 700 MB THERMAL RIDGE REMAINS IN PLACE
ACROSS THE STATE.
UPPER RIDGE AXIS DRIFTS VERY SLOWLY EASTWARD EARLY NEXT WEEK AS
DEEP TROUGH MOVES ONSHORE OVER THE PACIFIC NORTHWEST. BOTH GFS
AND ECMWF ALLOW LOW LEVEL MOISTURE TO CREEP BACK WESTWARD MON IN
THE ABSENCE OF STRONG FLOW ALOFT...WITH BOTH MODELS SUGGESTING AN
UPTURN IN TSRA OVER THE EASTERN HALF OF THE AREA MON
AFTERNOON/EVENING. WEAK UPPER LOW TRAPPED UNDER THE RIDGE MAY ALSO
AID IN UPWARD MOTION...AT LEAST THROUGH MON EVENING. UPPER TROUGH
INCHES CLOSER TO THE REGION TUE/WED...WITH DRYLINE SHARPENING UP
OVER THE EASTERN PLAINS. MAY THUS SEE DAILY ROUNDS OF TSRA ALONG
AND EAST OF THE DRYLINE EACH AFTERNOON TUE-THU...WHILE MOUNTAINS
UNFORTUNATELY STAY MAINLY DRY AND INCREASINGLY BREEZY THROUGH MID-
WEEK. --PETERSEN
&&
.AVIATION...VFR CONDITIONS ANTICIPATED DURING THE NEXT 24H AT
KCOS...KPUB AND KALS. THERE IS A VERY SLIGHT CHANCE OF A PASSING
TSRA AT KCOS LATE THIS AFTERNOON AND EARLY EVENING...AND LATE
TOMORROW AFTERNOON.
A WEAK COOL FRONT WILL CROSS THE KCOS REGION TOWARDS SUNRISE FRIDAY.
BRIEF WIND GUSTS TO 20 MPH MAY OCCUR AFTER FROPA. NO OTHER SENSIBLE
WX IS ANTICIPATED WITH THE FROPA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34/10
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
608 PM EDT THU MAY 31 2012
.SYNOPSIS...
A STRONG LOW PRESSURE SYSTEM WILL TRACK ACROSS THE OHIO VALLEY AND
INTO THE EASTERN GREAT LAKES FRIDAY INTO SATURDAY, DRAGGING A COLD
FRONT ACROSS THE AREA FRIDAY NIGHT. WEAK HIGH PRESSURE WILL TRY TO
BUILD IN FROM THE SOUTH FOR SATURDAY INTO EARLY SUNDAY BEFORE LOW
PRESSURE TO OUR EAST DEEPENS AND SENDS WEAK DISTURBANCES TOWARD OUR
AREA THROUGH TUESDAY. ANOTHER AREA OF LOW PRESSURE TRACKING ACROSS
THE UPPER PLAINS WILL MOVE ACROSS THE OHIO AND TENNESSEE VALLEYS
MONDAY AND TUESDAY BUT WILL LIKELY REMAIN TO OUR SOUTH AS IT IS
SUPPRESSED BY THE LOW OFF THE NEW ENGLAND COAST.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
NO BIG CHANGES WITH THIS ESTF UPDATE. WE DID USE A COMBINATION OF
THE HIRES WRF-ARW AND WRF-NMM TO ADJUST THE SLOW PROGRESSION OF
THE SEA BREEZE INLAND. BASED ON CURRENT PERFORMANCE (AND HOPEFULLY
FUTURE TRENDS) THEY WERE HANDLING IT BETTER THAN THE RAP OR HRRR.
OTHER THAN SOME INCREASE IN HIGH CLOUDINESS OVERNIGHT AS THE MID
LEVEL RIDGE AXIS ARRIVES, WE SHOULD HAVE FAIR WEATHER IN THE NEAR
TERM. WINDS WILL GO LIGHT FOR MOST OF THE NIGHT, BUT EASTERLY
WINDS MAY BEGIN TO PICK UP JUST PRIOR TO DAYBREAK. TEMPERATURES
WERE A BLEND OF GUIDANCE AND CONTINUITY. DEW POINTS OVER MOST
LOCATIONS HAD DROPPED LATE THIS AFTERNOON AND THERE MAY BE SOME
RADIATING THIS EVENING, BUT THE GROUND IS GETTING WARM AND THE
NIGHTS ARE RATHER SHORT.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
A WARM FRONT WILL TRY TO PUSH ACROSS THE AREA ON FRIDAY WHILE A COLD
FRONT APPROACHES FROM THE WEST. THERE IS SOME ISENTROPIC LIFT AHEAD
OF THE WARM FRONT, ALTHOUGH SATURATION TAKES A WHILE TO OCCUR. THE
MID LEVEL TROUGH AXIS MOVING INTO THE UPPER OHIO RIVER VALLEY, THE
TRIPLE POINT MOVING INTO CENTRAL PA AND THE APPROACHING COLD FRONT
LOOK MORE LIKE THE CUES FOR SIGNIFICANT RAINFALL. MOISTURE WILL BE
ON THE INCREASE THROUGH THE AFTERNOON, AND WE SEE AN APPROACHING
UPPER JET, SOME GOOD MID LEVEL Q-VECTOR CONVERGENCE, LOWER LEVEL
FRONTOGENESIS, AND DIFFERENTIAL DIVERGENCE BEGINNING TO COME
TOGETHER VERY NEAR US. INSTABILITY INVADES BEHIND THE WARM FRONT,
AND THAT LIKELY FAVORS SOUTHERN AND WESTERN PARTS OF OUR AREA. THERE
IS VERY GOOD BULK SHEAR AS ONE APPROACHES THE TRIPLE POINT. WE HAVE
NO ENHANCED WORDING THROUGH THE SHORT TERM, BUT STRONG STORMS
CERTAINLY MAY BE APPROACHING OUR WESTERN ZONES BY LATE FRIDAY
AFTERNOON. OUR POPS BY THE END OF THE DAY RANGE FROM LIKELY WEST TO
SLIGHT CHANCE OFF THE COAST. TEMPERATURES ARE VERY CLOSE TO
CONTINUITY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
A COLD FRONT WILL MOVE THROUGH THE REGION ON FRIDAY NIGHT AS THE
STRONG PARENT LOW PRESSURE SYSTEM MOVES INTO SOUTHEASTERN CANADA AND
MOVES VERY LITTLE THROUGH EARLY SUNDAY. SURFACE LOW PRESSURE
DEVELOPS ALONG A BOUNDARY JUST TO OUR NORTH AND MOVES OVER THE NEW
ENGLAND COAST WHILE SLOWLY DRIFTING EASTWARD. A WEAK AREA OF HIGH
PRESSURE WILL TRY TO BUILD IN FROM THE SOUTH FOR SATURDAY AND EARLY
SUNDAY. THE SOUTHEASTERN CANADIAN LOW WILL THEN BEGIN TO MOVE
SOUTHEAST ON SUNDAY AND EVENTUALLY ABSORB THE NEW ENGLAND COASTAL
LOW. THIS MOVEMENT WILL THEN DRAG A BOUNDARY ACROSS THE AREA ON
SUNDAY NIGHT. THE LOW SEEMS TO SET UP SHOP OFF THE NEW ENGLAND COAST
THROUGH ABOUT TUESDAY. ENERGY ROTATING AROUND THIS CLOSED LOW WILL
BRING UNSETTLED WEATHER ACROSS OUR AREA THROUGH ABOUT MIDWEEK.
ANOTHER AREA OF LOW PRESSURE TRACKING ACROSS THE UPPER PLAINS WILL
MOVE ACROSS THE OHIO AND TENNESSEE VALLEYS MONDAY AND TUESDAY BUT
WILL LIKELY REMAIN TO OUR SOUTH AS IT IS SUPPRESSED BY THE LOW OFF
THE NEW ENGLAND COAST. THE STRONGER SURFACE LOW TO OUR NORTHEAST
FINALLY STARTS TO MOVE EASTWARD ON WEDNESDAY. THE UPPER LEVEL LOW
SLOWLY MOVES TO EAST BUT REMAINS NEARBY THROUGH THE END OF NEXT
WEEK.
FOR FRIDAY NIGHT WE MAY SEE HEAVY RAIN AND GUSTY WINDS AS
THUNDERSTORMS MOVE THROUGH AHEAD OF AND ALONG THE FRONTAL PASSAGE.
AREAS THAT HAVE SEEN COPIOUS AMOUNTS OF RAIN OVER THE PAST WEEK MAY
SEE SOME MORE AS PRECIPITABLE WATER VALUES REMAIN FAIRLY HIGH. THIS
MAY CONTRIBUTE TO LOCALIZED FLOODING ISSUES SO EXERCISE CAUTION IF
OUT WHEN STORMS MOVE THROUGH. WE WILL CONTINUE TO MONITOR THE HEAVY
RAINFALL THREAT.
AN UNSETTLED PERIOD OF WEATHER IS EXPECTED THROUGH THE EXTENDED AND
WITH THE EXCEPTION OF SATURDAY, WE CANNOT RULE OUT THE POSSIBILITY
OF SHOWERS AND/OR THUNDERSTORMS TO OCCUR. CONFIDENCE IS NOT
PARTICULARLY HIGH AT THIS POINT SO WE HAVE KEPT POPS MAINLY IN THE
CHC/SCHC RANGE.
OVERALL THOUGH, WE WILL SEE A COOLING TREND AS COOLER AIR GETS
PUSHED DOWN ACROSS THE REGION THROUGH THE PERIOD. WE WENT WITH A
BLEND OF HPC GUIDANCE AND CONTINUITY FOR TEMPERATURES THROUGH THE
PERIOD.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
WE FORECAST VFR CONDITIONS THROUGH THE SHORT TERM, ALTHOUGH
CONDITIONS MAY BEGIN TO DETERIORATE IN CONVECTION LATE IN THE
AFTERNOON WEST.
FOR TONIGHT, WINDS SHOULD BE LIGHT UNTIL AROUND DAYBREAK WHEN THEY
WILL BEGIN TO DEVELOP AN EASTERLY COMPONENT AND APPROACH 10 KT.
HIGH CLOUDS WILL BEGIN TO INVADE AND WE DON`T EXPECT VISIBILITY
ISSUES. CLOUDS WILL INCREASE AND CEILINGS WILL LOWER DURING THE DAY
ON FRIDAY. WINDS MAINLY WILL BE FROM THE SOUTHEAST AND WILL DEVELOP
SOME GUSTS OF AROUND 20 KT.
CONVECTION IS MOST LIKELY IN THE AFTERNOON WEST, AND IT MAY CARRY
SOME STRONG WIND GUSTS AND IFR CONDITIONS IF IT DEVELOPS.
OUTLOOK...
FRIDAY NIGHT...SHOWERS AND THUNDERSTORMS DURING THE EVENING AND
OVERNIGHT HOURS WILL CAUSE CONDITIONS TO DETERIORATE TO MVFR/IFR.
THERE IS ALSO THE POTENTIAL FOR LOCAL DOWNPOURS AND GUSTY WINDS.
SOUTHEAST WINDS AROUND 10 TO 15 KNOTS WILL TURN TO THE SOUTH AND
THEN SOUTHWEST DURING THE LATE EVENING BEFORE SHIFTING TO WEST
TOWARD MORNING.
SATURDAY...BECOMING VFR BY EARLY SATURDAY MORNING WITH WEST WINDS 10
TO 15 KNOTS. WINDS MAY BECOME GUSTY DURING THE DAY.
SUNDAY...VFR CONDITIONS WITH WEST WINDS AROUND 10 KNOTS. SHOWERS ARE
POSSIBLE LATER IN THE DAY AND COULD CAUSE WHICH COULD CAUSE LOWER
VISIBILITIES AND/OR CEILINGS TO OCCUR.
MONDAY...VFR WITH A WEST TO NORTHWEST WIND AROUND 10 KNOTS.
AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE WHICH COULD CAUSE
LOWER VISIBILITIES AND/OR CEILINGS TO OCCUR.
TUESDAY...MAINLY VFR CONDITIONS EXPECTED WITH SHOWERS AND POSSIBLY A
THUNDERSTORM POSSIBLE, MAINLY TOWARD THE AFTERNOON HOURS. NORTH TO
NORTHEAST WINDS AROUND 10 KNOTS.
&&
.MARINE...
SUB-ADVISORY CONDITIONS ARE FORECAST UNTIL THE EARLY EVENING ON
FRIDAY. TONIGHT SHOULD SEE LIGHT WINDS DEVELOPING AN EASTERLY
COMPONENT AND THEN INCREASING BY DAYBREAK. SEAS SHOULD REMAIN AT OR
BELOW 3 FT. THEN, EAST TO SOUTHEAST WINDS WILL CONTINUE TO INCREASE
DURING THE DAY ON FRIDAY UNTIL GUSTS TO 25 KT AND SEAS OF 5 FT
DEVELOP LATE.
OUTLOOK...
A STRONG COLD FRONT WILL CROSS THE AREA WATERS ON FRIDAY NIGHT
ACCOMPANIED BY STRONG GUSTY WINDS, RAIN AND POSSIBLY SOME
THUNDERSTORMS. ALTHOUGH AN INVERSION IS PRESENT ON MODEL SOUNDINGS,
THERE APPEARS TO BE A STRONG ENOUGH FLOW TO SUSTAIN SMALL CRAFT
ADVISORY GUSTS. THE STRONG SOUTH TO SOUTHEASTERLY FLOW AHEAD OF THE
FRONT WILL BRING GUSTS AROUND 25-30 KNOTS ALONG THE OCEAN AND 20-25
KNOTS IN THE DELAWARE BAY. SOME ENHANCEMENT ACROSS THE MOUTH OF THE
DELAWARE BAY COULD ALSO INCREASE GUSTS FOR A PERIOD AS WELL AHEAD OF
THE FRONT. SEAS ALSO BEGIN TO INCREASE IN THE SOUTHERLY FLOW AND
COULD REACH 5 FEET BY FRIDAY NIGHT. AS A RESULT, WE HAVE ISSUED A
SMALL CRAFT ADVISORY ON THE OCEAN FRONT FROM 6PM FRIDAY THROUGH 2PM
SATURDAY. A SMALL CRAFT FOR THE DELAWARE BAY WILL RUN FROM 6PM
FRIDAY THROUGH 10AM SATURDAY.
AS THE FRONT MOVES THROUGH THE WINDS TURN TO THE SOUTH THEN
SOUTHWEST AND EVENTUALLY BECOME MORE WESTERLY BY SATURDAY MORNING.
WINDS WILL THEN REMAIN WESTERLY THROUGH THE WEEKEND AND INTO THE NEW
WEEK. SEAS AND WINDS SUBSIDE ON SATURDAY AND WE DO NOT ANTICIPATE
THE NEED FOR ANY SMALL CRAFT ADVISORY HEADLINES FROM SATURDAY
THROUGH THE START OF THE NEW WEEK.
&&
.TIDES/COASTAL FLOODING...
DEPARTURES OF APPROXIMATELY THREE-QUARTERS OF A FOOT ARE NECESSARY
TO BEGIN MINOR TIDAL FLOODING ALONG OUR ATLANTIC COASTLINE, RARITAN
BAY, DELAWARE BAY AND THE TIDAL DELAWARE RIVER WITH THE HIGHER HIGH
TIDE FROM EARLY FRIDAY EVENING THROUGH MIDNIGHT. THE INCREASE IN
EASTERLY WINDS COULD MAKE IT HAPPEN, AND WE WILL MENTION THE
POSSIBILITY OF MINOR TIDAL FLOODING OVER THOSE SHORELINES IN THE
HWO.
THE MARYLAND EASTERN SHORE WOULD NEED DEPARTURES IN EXCESS OF ONE
FOOT, AND WE PRESENTLY DON`T ANTICIPATE ANY PROBLEMS THERE.
THE NEXT TIME FRAME OF CONCERN IS THE SUNDAY THROUGH TUESDAY HIGH
TIDE CYCLES. WITH THE FULL MOON EXPECTED ON MONDAY AND HIGHER
ASTRONOMICAL TIDES, LOCATIONS ALONG OUR ATLANTIC COASTLINE, RARITAN
BAY, DELAWARE BAY AND THE TIDAL DELAWARE RIVER MAY EXPERIENCE
MINOR TIDAL FLOODING. ASTRONOMICAL HIGH TIDES ARE ONLY RUNNING
0.2-0.4 TENTHS BELOW MINOR COASTAL FLOODING THRESHOLDS SO WE WILL
KEEP AN EYE ON THIS OVER THE NEXT FEW DAYS. ONE ITEM IN OUR FAVOR
APPEARS TO BE AN OFFSHORE FLOW, WHICH WILL HELP TO LIMIT POTENTIAL
FOR FLOODING.
AGAIN, WITH DEPARTURES AROUND ONE FOOT, NO PROBLEMS ARE
ANTICIPATED ALONG THE EASTERN SHORE OF MARYLAND ON THE CHESAPEAKE
BAY AT THIS TIME.
&&
.RIP CURRENTS...
WITH A FORECAST INCREASE OF SOUTHEAST WINDS DURING THE AFTERNOON
ON FRIDAY AND WITH US GETTING CLOSER TO THE FULL MOON, OUR IN HOUSE
PROCEDURE TAKES NEW JERSEY INTO A MODERATE RISK OF RIP CURRENTS AND
PLACES DELAWARE BEACHES JUST SHORT. WITH THE WINDS EXPECTED TO
INCREASE IN DELAWARE FIRST, WE DECIDED TO OUTLOOK ALL AREAS FOR A
MODERATE RISK ON FRIDAY. PLEASE LOOK FOR UPDATED INFORMATION ON
FRIDAY MORNING.
&&
.CLIMATE...
IN SPITE OF ANOTHER LA NINA WINTER AND A MILD ONE AT THAT, BOTH
APRIL AND MAY WERE UNSEASONABLY WARM AGAIN FOR THE FOURTH
CONSECUTIVE SPRING. SINCE 1872, THIS COMBINATION HAS OCCURRED ONLY
TWENTY-ONE TIMES, BUT NOW NINE TIMES SINCE 1990. WE HAVE ALSO HAVE HAD
NINE CONSECUTIVE MONTHS OF ABOVE NORMAL TEMPERATURES. BY OUR
CATEGORY DEFINITION UNSEASONABLY COOL/NORMAL/UNSEASONABLY WARM MONTHS
ARE DIVIDED INTO THIRDS. THIS IS ONLY THE 5TH TIME THIS HAS OCCURRED
AFTER A LA NINA WINTER AND GIVES US A LONE FOURSOME OF ANALOGS FOR
THIS UPCOMING SUMMER. THE SUMMER OF 1985 WAS THE LONE COOL ONE IN
THE FOURSOME AND HAS WEIGHED DOWN THE ANALOG AVERAGE. WE`LL FIND OUT
ON SEPTEMBER 1ST IF THIS WAS A GOOD OR BAD INCLUSION. THE OTHER
THREE SUMMERS WERE WARMER THAN NORMAL EVEN USING THE CURRENT
1981-2010 NORMALS. THAT THREESOME AVERAGE WAS 77.0 DEGREES. WE ARE
CERTAIN SOMEONE WILL NOTICE THAT ALL OF THESE ANALOG SUMMERS SAW
TROPICAL ACTIVITY THAT AFFECTED OUR AREA: CONNIE AND DIANE IN 1955,
GLORIA IN 1985, ALLISON IN 2001 AND IRENE IN 2011. WITH THREE OF
THEM OCCURRING IN AUGUST, THEY SKEWED THE SUMMER PRECIPITATION
AVERAGE TO WET. THE PRECIPITATION ASSOCIATED WITH ALLISON WAS NOT
ENOUGH TO OFFSET A VERY DRY JULY AND AUGUST.
YEAR JUNE AVG JULY AVG AUGUST AVG SUMMER AVG SUMMER PCPN
1955 69.2 81.4 78.1 76.2 14.80
1985 68.8 75.4 74.1 72.8 9.36
2001 75.2 75.4 79.9 76.8 8.20
2011 75.4 82.4 76.1 78.0 22.02
AVG 72.2 78.7 77.1 76.0 13.60
1981-2010 NML 73.3 78.1 76.6 76.0 11.28
THE OFFICIAL CPC OUTLOOK FOR THIS SUMMER IS FOR A GREATER CHANCE OF
IT BEING WARMER THAN NORMAL IN THE SOUTHERN PART OF OUR CWA AND
EQUAL CHANCES OF IT BEING EITHER WARMER OR COOLER THAN NORMAL IN THE
NORTHERN PART OF OUR CWA. THE PRECIPITATION OUTLOOK IS FOR EQUAL
CHANCES OF IT BEING EITHER DRIER OR WETTER THAN NORMAL.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM FRIDAY TO 2 PM EDT SATURDAY FOR
ANZ450>455.
SMALL CRAFT ADVISORY FROM 6 PM FRIDAY TO 10 AM EDT SATURDAY
FOR ANZ430-431.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...DELISI
SHORT TERM...DELISI
LONG TERM...MEOLA
AVIATION...DELISI/MEOLA
MARINE...DELISI/MEOLA
TIDES/COASTAL FLOODING...MEOLA/DELISI
RIP CURRENTS...GIGI
CLIMATE...GIGI
AREA FORECAST DISCUSSION...CORRECTED
NWS MIAMI FL
756 PM EDT FRI JUN 1 2012
.UPDATE...SOME MAJOR ADJUSTMENTS PLANNED FOR THE EVENING UPDATES
BASED ON CURRENT TRENDS. MID LEVEL TROUGH THAT WAS DIGGING INTO
THE SOUTHEAST STATES AND HELPING TO LIFT DEEP TROPICAL MOISTURE
NORTHWARD IS EVIDENT ON WATER VAPOR MOVING INTO THE NORTHEAST GULF
OF MEXICO WHICH IN TURN IS AIDING IN SHIFTING THE BULK OF THE
CONVECTION EAST AND SOUTH OF THE PENINSULA. IN ADDITION, THIS IS
COMING IN LINE WITH THE LOSS OF DIURNAL HEATING OVER THE NEXT HOUR
AND FOR THESE REASONS IT APPEARS THE RISK OF FLOODING RAINS HAS
BEEN SUBSTANTIALLY REDUCED. THE HRRR WHICH HAS ACTUALLY BEEN OVER
ZEALOUS WITH THE ACTIVITY TODAY FORECASTS THE CONVECTION TO WEAKEN
THROUGH THE EVENING WHICH SEEMS REASONABLE GIVEN THE ABOVE
DISCUSSION. SO FOR ALL OF THESE REASONS, PLAN TO LOWER POPS TO
ONLY SCT LEVELS FOR THE NIGHTTIME HOURS AND CANCEL THE FFA FOR ALL
OF S FL.
KOB
&&
.PREV DISCUSSION... /ISSUED 626 PM EDT FRI JUN 1 2012/
AVIATION...TSRA MOVG OFSHR ATTM AND VCSH THRU 02Z WITH PSBL
REDVLPMNT TOWARD 12Z WITH VCTS AFT 16Z. OTRW...VFR E COAST FOR THE
MOST PART. SFC WNDS BCMG SW GENERALLY LESS THAN 10 KTS AND
PERSISTING. ATTM GUIDANCE INDICATES NO E COAST SEA BRZE SATURDAY.
AT KAPF....VCSH OVRNITE INTO SATURDAY AND PSBL MVFR CIGS BUT NOT
IN TAFS ATTM. SFC WNDS SW 10 KTS OR LESS.
PREV DISCUSSION... /ISSUED 223 PM EDT FRI JUN 1 2012/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
LATEST WATER VAPOR IMAGERY SHOWED THE UPPER TROUGH AXIS EXTENDING
SOUTH ACROSS THE REGION AND THE EASTERN GULF WITH A FEW LEAD
SHORTWAVES WITHIN THE SUB-TROPICAL JET LIFTING NE ACROSS THE STATE
AHEAD OF IT. UPPER HEIGHT FALLS COMBINED WITH A WEAK SURFACE TROUGH
AND PRECIPITABLE WATER VALUES IN THE 2 TO 2.5 INCH RANGE HAS
GENERATED A LARGE AREA OF DEEP MOIST CONVECTION AROUND AND JUST WEST
OF THE KEYS EARLIER THIS AFTERNOON. EXPECT THIS ACTIVITY TO CONTINUE
TO SPREAD EAST AND NORTHEAST ACROSS THE LOCAL AREA THROUGH THE
AFTERNOON AND EVENING PERIODS AS THE UPPER TROUGH AND COLD FRONT
APPROACH THE AREA FROM THE WEST AND NORTHWEST. THE FLOOD WATCH
REMAINS IN EFFECT INTO TONIGHT AND MAY NEED TO BE EXTENDED INTO
SATURDAY MORNING DEPENDING ON THE EVOLUTION OF THIS SYSTEM AND WHERE
THE BULK OF THE CONVECTION BECOMES CONCENTRATED. IN ADDITION TO THE
RAINFALL CONCERNS THROUGH TONIGHT...THE LATEST VISIBLE SATELLITE
IMAGERY WAS INDICATING A FEW BREAKS IN THE COVERAGE OVER THE
INTERIOR PORTIONS OF THE AREA...WHICH MAY ALLOW FOR SOME
DESTABILIZATION THROUGH THE AFTERNOON PERIOD. IF SO, A FEW STRONG
STORMS DEVELOPING CANNOT BE RULED OUT WITH THE MAIN CONCERN BEING
DAMAGING STRAIGHT LINE WIND GUSTS.
DESPITE SOME MINOR TIMING DIFFERENCES THAT WERE NOTED FROM EARLIER
MODEL SOLUTIONS IN PREVIOUS DISCUSSIONS...THE LATEST MODEL CYCLE
APPEARS TO BE COMING INTO BETTER AGREEMENT AND INDICATES THE DRIER
AIR BEGINNING TO SPREAD EAST AND SOUTHEAST ACROSS SOUTH FLORIDA
THROUGH THE DAY SATURDAY. AS A RESULT...WILL INDICATE A GENERAL
DRYING PATTERN OR TRANSITION PERIOD THROUGH THE DAY SATURDAY FROM
NORTHWEST TO SOUTHEAST AS THE UPPER TROUGH MOVES THROUGH. THIS DRY
AIR COMBINED WITH SUBSIDENCE ON THE BACK SIDE OF THE TROUGH SHOULD
LEAD TO CLEARING CONDITIONS COME SATURDAY NIGHT. HOWEVER...THE
LATEST ECMWF 00Z RUN STILL REMAINS SLIGHTLY SLOWER WITH THIS DRIER
AIR SPREADING ACROSS THE AREA THROUGH THIS TIME AND CONTINUES TO
MAINTAIN A DECENT SOURCE OF DEEP LAYER MOISTURE REMAINING IN PLACE
ACROSS THE SOUTHEASTERN HALF OF THE AREA THROUGH A GOOD PORTION OF
THE AREA SATURDAY. CONSIDERING SOME UNCERTAINTIES WITH REGARD TO THE
DRIER AIR MOVING OVER THE AREA...WE WILL NOT COMPLETELY RULE OUT THE
POTENTIAL FOR ADDITIONAL RAINFALL THROUGH THE EARLY PORTION OF THE
DAY SATURDAY...ESPECIALLY ACROSS THE SOUTHEASTERN SECTIONS OF THE
LOCAL AREA. AS A RESULT...WILL KEEP THE RAINFALL CHANCES UP THROUGH
THE FIRST HALF OF THE DAY...MAINLY SOUTHEAST OF LINE EXTENDING
SOUTHWEST FROM PALM BEACH COUNTY TO NAPLES.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...PLENTY OF DEEP LAYER DRY
AIR AND SUBSIDENCE ALONG WITH THE PREVIOUSLY DISCUSSED FRONTAL
BOUNDARY MOVING INTO THE AREA WILL LIMIT THE RAINFALL CHANCES
THROUGH THE END OF THE SHORT-TERM FORECAST PERIOD. TEMPERATURES
WILL CLIMB BACK TO AROUND 90 THROUGH THIS TIME WITH THE WARMEST
CONDITIONS EXPECTED INLAND AND ACROSS THE EASTERN AREAS WITH THE
WESTERLY FLOW CONTINUING.
LONG TERM (MONDAY-WEDNESDAY)...
A LOW LEVEL RIDGE AXIS WILL ESTABLISH ITSELF OVER SOUTH FLORIDA
BY MONDAY AND REMAIN NEARLY STATIONARY THROUGH THURSDAY, WITH
TROUGHING OVER THE SOUTHEAST STATES. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY WEST TO SOUTHWESTERLY FLOW, WITH THE WARMEST
DAYTIME TEMPS OVER EASTERN AREAS. SUFFICIENT MOISTURE COMBINED
WITH DAILY SEA BREEZE FORMATION WILL BE ENOUGH TO RESULT IN
ISOLATED TO SCATTERED STORMS EACH AFTERNOON.
MARINE...
LIGHT TO MODERATE SOUTHERLY WINDS WILL CONTINUE THROUGH SATURDAY AS
A FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. NUMEROUS TO
WIDESPREAD SHOWERS AND STORMS WILL CONTINUE TO IMPACT THE MARINE
AREAS THROUGH SATURDAY...WHICH WILL LEAD TO PERIODS WITH GUSTY WINDS
AND CHOPPIER CONDITIONS IN AND AROUND THE HEAVIER ACTIVITY. DRIER
CONDITIONS WILL BE ANTICIPATED SATURDAY NIGHT THROUGH MONDAY WITH
LIGHT WINDS AND LOW SEAS CONTINUING.
AVIATION...
AN AREA OF RAIN WITH EMBEDDED STORMS WILL CONTINUE TO MOVE
NORTHEAST FROM THE SOUTHEAST GULF OF MEXICO INTO THE SOUTH FLORIDA
THIS AFTERNOON...AND AFFECT ALL OF THE TAF SITES IN THE CWA. SO
WILL CONTINUE THE VCTS FOR ALL OF THE TAF SITES THROUGH 02Z.
THE THUNDERSTORM THREAT SHOULD END EARLY THIS EVENING...BUT THE
SHOWERS WILL CONTINUE THROUGH THE NIGHT AT ALL OF THE TAF SITES
UNTIL THE TROUGH OF LOW PRESSURE SWINGS THROUGH THE CWA FROM THE
WEST. SO WILL CONTINUE THE VCSH AFTER 02Z FOR TONIGHT FOR ALL OF THE
TAF SITES OF THE CWA.
THE VIS AND CEILINGS WILL REMAIN IN THE VFR CONDITIONS TONIGHT...BUT
COULD FALL DOWN INTO THE MVFR CONDITIONS THIS AFTERNOON WITH THE
PASSAGE OF THE RAINS AND THE THUNDERSTORMS.
THE WINDS WILL BE FROM THE SOUTHEAST AROUND 10 KNOTS THIS AFTERNOON
FOR ALL OF THE TAF SITES ACROSS SOUTH FLORIDA THIS
AFTERNOON...BEFORE SWINGING TO A SOUTHWEST DIRECTION AT 5 KNOTS OR
LESS TONIGHT MAINLY AFTER 2Z.
FIRE WEATHER...NO CONCERNS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
755 PM EDT FRI JUN 1 2012
.UPDATE...SOME MAJOR ADJUSTMENTS PLANNED FOR THE EVENING UPDATES
BASED ON CURRENT TRENDS. MID LEVEL TROUGH THAT WAS DIGGING INTO
THE SOUTHEAST STATES AND HELPING TO LIFT DEEP TROPICAL MOISTURE
NORTHWARD IS EVIDENT ON WATER VAPOR MOVING INTO THE NORTHEAST GULF
OF MEXICO WHICH IN TURN IS AIDING IN SHIFTING THE BULK OF THE
CONVECTION EAST AND SOUTH OF THE PENINSULA. IN ADDITION, THIS IS
COMING IN LINE WITH THE LOSS OF DIURNAL HEATING OVER THE NEXT HOUR
AND FOR THESE REASONS IT APPEARS THE RISK OF FLOODING RAINS HAS
BEEN SUBSTANTIALLY REDUCED. THE HRRR WHICH HAS ACTUALLY BEEN OVER
ZEALOUS WITH THE ACTIVITY TODAY FORECASTS THE CONVECTION TO WEAKEN
THROUGH THE EVENING WHICH SEEMS REASONABLE GIVEN THE ABOVE
DISCUSSION. SO FOR ALL OF THESE REASONS, PLAN TO LOWER POPS TO
ONLY SCT LEVELS FOR THE NIGHTTIME HOURS AND CANCEL THE FFA FOR ALL
OF S FL.
KOB
&&
.PREV DISCUSSION... /ISSUED 626 PM EDT FRI JUN 1 2012/
AVIATION...TSRA MOVG OFSHR ATTM AND VCSH THRU 02Z WITH PSBL
REDVLPMNT TOWARD 12Z WITH VCTS AFT 16Z. OTRW...VFR E COAST FOR THE
MOST PART. SFC WNDS BCMG SW GENERALLY LESS THAN 10 KTS AND
PERSISTING. ATTM GUIDANCE INDICATES NO E COAST SEA BRZE SATURDAY.
AT KAPF....VCSH OVRNITE INTO SATURDAY AND PSBL MVFR CIGS BUT NOT
IN TAFS ATTM. SFC WNDS SW 10 KTS OR LESS.
PREV DISCUSSION... /ISSUED 223 PM EDT FRI JUN 1 2012/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
LATEST WATER VAPOR IMAGERY SHOWED THE UPPER TROUGH AXIS EXTENDING
SOUTH ACROSS THE REGION AND THE EASTERN GULF WITH A FEW LEAD
SHORTWAVES WITHIN THE SUB-TROPICAL JET LIFTING NE ACROSS THE STATE
AHEAD OF IT. UPPER HEIGHT FALLS COMBINED WITH A WEAK SURFACE TROUGH
AND PRECIPITABLE WATER VALUES IN THE 2 TO 2.5 INCH RANGE HAS
GENERATED A LARGE AREA OF DEEP MOIST CONVECTION AROUND AND JUST WEST
OF THE KEYS EARLIER THIS AFTERNOON. EXPECT THIS ACTIVITY TO CONTINUE
TO SPREAD EAST AND NORTHEAST ACROSS THE LOCAL AREA THROUGH THE
AFTERNOON AND EVENING PERIODS AS THE UPPER TROUGH AND COLD FRONT
APPROACH THE AREA FROM THE WEST AND NORTHWEST. THE FLOOD WATCH
REMAINS IN EFFECT INTO TONIGHT AND MAY NEED TO BE EXTENDED INTO
SATURDAY MORNING DEPENDING ON THE EVOLUTION OF THIS SYSTEM AND WHERE
THE BULK OF THE CONVECTION BECOMES CONCENTRATED. IN ADDITION TO THE
RAINFALL CONCERNS THROUGH TONIGHT...THE LATEST VISIBLE SATELLITE
IMAGERY WAS INDICATING A FEW BREAKS IN THE COVERAGE OVER THE
INTERIOR PORTIONS OF THE AREA...WHICH MAY ALLOW FOR SOME
DESTABILIZATION THROUGH THE AFTERNOON PERIOD. IF SO, A FEW STRONG
STORMS DEVELOPING CANNOT BE RULED OUT WITH THE MAIN CONCERN BEING
DAMAGING STRAIGHT LINE WIND GUSTS.
DESPITE SOME MINOR TIMING DIFFERENCES THAT WERE NOTED FROM EARLIER
MODEL SOLUTIONS IN PREVIOUS DISCUSSIONS...THE LATEST MODEL CYCLE
APPEARS TO BE COMING INTO BETTER AGREEMENT AND INDICATES THE DRIER
AIR BEGINNING TO SPREAD EAST AND SOUTHEAST ACROSS SOUTH FLORIDA
THROUGH THE DAY SATURDAY. AS A RESULT...WILL INDICATE A GENERAL
DRYING PATTERN OR TRANSITION PERIOD THROUGH THE DAY SATURDAY FROM
NORTHWEST TO SOUTHEAST AS THE UPPER TROUGH MOVES THROUGH. THIS DRY
AIR COMBINED WITH SUBSIDENCE ON THE BACK SIDE OF THE TROUGH SHOULD
LEAD TO CLEARING CONDITIONS COME SATURDAY NIGHT. HOWEVER...THE
LATEST ECMWF 00Z RUN STILL REMAINS SLIGHTLY SLOWER WITH THIS DRIER
AIR SPREADING ACROSS THE AREA THROUGH THIS TIME AND CONTINUES TO
MAINTAIN A DECENT SOURCE OF DEEP LAYER MOISTURE REMAINING IN PLACE
ACROSS THE SOUTHEASTERN HALF OF THE AREA THROUGH A GOOD PORTION OF
THE AREA SATURDAY. CONSIDERING SOME UNCERTAINTIES WITH REGARD TO THE
DRIER AIR MOVING OVER THE AREA...WE WILL NOT COMPLETELY RULE OUT THE
POTENTIAL FOR ADDITIONAL RAINFALL THROUGH THE EARLY PORTION OF THE
DAY SATURDAY...ESPECIALLY ACROSS THE SOUTHEASTERN SECTIONS OF THE
LOCAL AREA. AS A RESULT...WILL KEEP THE RAINFALL CHANCES UP THROUGH
THE FIRST HALF OF THE DAY...MAINLY SOUTHEAST OF LINE EXTENDING
SOUTHWEST FROM PALM BEACH COUNTY TO NAPLES.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...PLENTY OF DEEP LAYER DRY
AIR AND SUBSIDENCE ALONG WITH THE PREVIOUSLY DISCUSSED FRONTAL
BOUNDARY MOVING INTO THE AREA WILL LIMIT THE RAINFALL CHANCES
THROUGH THE END OF THE SHORT-TERM FORECAST PERIOD. TEMPERATURES
WILL CLIMB BACK TO AROUND 90 THROUGH THIS TIME WITH THE WARMEST
CONDITIONS EXPECTED INLAND AND ACROSS THE EASTERN AREAS WITH THE
WESTERLY FLOW CONTINUING.
LONG TERM (MONDAY-WEDNESDAY)...
A LOW LEVEL RIDGE AXIS WILL ESTABLISH ITSELF OVER SOUTH FLORIDA
BY MONDAY AND REMAIN NEARLY STATIONARY THROUGH THURSDAY, WITH
TROUGHING OVER THE SOUTHEAST STATES. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY WEST TO SOUTHWESTERLY FLOW, WITH THE WARMEST
DAYTIME TEMPS OVER EASTERN AREAS. SUFFICIENT MOISTURE COMBINED
WITH DAILY SEA BREEZE FORMATION WILL BE ENOUGH TO RESULT IN
ISOLATED TO SCATTERED STORMS EACH AFTERNOON.
MARINE...
LIGHT TO MODERATE SOUTHERLY WINDS WILL CONTINUE THROUGH SATURDAY AS
A FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. NUMEROUS TO
WIDESPREAD SHOWERS AND STORMS WILL CONTINUE TO IMPACT THE MARINE
AREAS THROUGH SATURDAY...WHICH WILL LEAD TO PERIODS WITH GUSTY WINDS
AND CHOPPIER CONDITIONS IN AND AROUND THE HEAVIER ACTIVITY. DRIER
CONDITIONS WILL BE ANTICIPATED SATURDAY NIGHT THROUGH MONDAY WITH
LIGHT WINDS AND LOW SEAS CONTINUING.
AVIATION...
AN AREA OF RAIN WITH EMBEDDED STORMS WILL CONTINUE TO MOVE
NORTHEAST FROM THE SOUTHEAST GULF OF MEXICO INTO THE SOUTH FLORIDA
THIS AFTERNOON...AND AFFECT ALL OF THE TAF SITES IN THE CWA. SO
WILL CONTINUE THE VCTS FOR ALL OF THE TAF SITES THROUGH 02Z.
THE THUNDERSTORM THREAT SHOULD END EARLY THIS EVENING...BUT THE
SHOWERS WILL CONTINUE THROUGH THE NIGHT AT ALL OF THE TAF SITES
UNTIL THE TROUGH OF LOW PRESSURE SWINGS THROUGH THE CWA FROM THE
WEST. SO WILL CONTINUE THE VCSH AFTER 02Z FOR TONIGHT FOR ALL OF THE
TAF SITES OF THE CWA.
THE VIS AND CEILINGS WILL REMAIN IN THE VFR CONDITIONS TONIGHT...BUT
COULD FALL DOWN INTO THE MVFR CONDITIONS THIS AFTERNOON WITH THE
PASSAGE OF THE RAINS AND THE THUNDERSTORMS.
THE WINDS WILL BE FROM THE SOUTHEAST AROUND 10 KNOTS THIS AFTERNOON
FOR ALL OF THE TAF SITES ACROSS SOUTH FLORIDA THIS
AFTERNOON...BEFORE SWINGING TO A SOUTHWEST DIRECTION AT 5 KNOTS OR
LESS TONIGHT MAINLY AFTER 2Z.
FIRE WEATHER...NO CONCERNS.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR COASTAL BROWARD-
COASTAL COLLIER-COASTAL MIAMI DADE-COASTAL PALM BEACH-FAR
SOUTH MIAMI DADE-GLADES-HENDRY-INLAND BROWARD-INLAND
COLLIER-INLAND MIAMI DADE-INLAND PALM BEACH-MAINLAND MONROE-
METRO BROWARD-METRO MIAMI DADE-METRO PALM BEACH.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
201 AM EDT THU MAY 31 2012
.AVIATION...
A LIGHT WESTERLY TO SOUTHWESTERLY FLOW WILL PREVAIL ACROSS ALL
TERMINALS THROUGH THE EARLY MORNING HOURS WITH THE EAST COAST
TERMINALS HAVING PERIODS WITH VARIABLE WINDS OR NEAR CALM. MAINLY
VFR CONDITIONS EXPECTED TO PREVAIL ACROSS ALL TERMINALS THROUGH THE
MORNING HOURS. A SURGE OF TROPICAL MOISTURE IS MOVING NORTHWARD
INTO THE REGION WITH CONVECTION EXPECTED ACROSS SOUTH FLORIDA BY
LATE MORNING AND THE AFTERNOON. SHOWERS AND THUNDERSTORMS MAINLY
EXPECTED IN VICINITY OF EAST COAST TERMINALS. A SSE SEA BREEZE IS
POSSIBLE FOR EAST COAST TERMINALS AROUND 17-20Z BUT WINDS COULD
REMAIN SSW AT TERMINALS KTMB AND KOPF IF SEA BREEZE DOES NOT
PENETRATE THAT FAR INLAND. WITH AFTERNOON AND EVENING CONVECTION
PERIODS OF SUB-VFR TO BRIEF PERIODS OF IFR CONDITIONS POSSIBLE
WITH SHOWERS/THUNDERSTORMS MAINLY EAST COAST TERMINALS.
60
&&
.PREV DISCUSSION... /ISSUED 638 PM EDT WED MAY 30 2012/
AVIATION...AS REMNANTS OF BERYL MOV NE ALG THE SE U.S. COAST...A
RDG OF SFC HI PRES...XTNDG W FM THE SW N ATLC OVR THE LWR FLA
STRAITS AND N CUBA INTO THE SE GULF OF MEX...SLOLY MOVS N AND OVR S
FLA AFT 31/12Z. AS THE RDG MOVS N...DEEP TROPICAL MOISTURE OVR THE
SW CARIB IS PULLED NORTHWARD. BUT...VFR XPCTD ALL TERMINALS THRU
31/18Z THOUGH SOME SHRA/PSBL ISOLD TSRA PSBL W COAST AND PSBLY
AFFECTING KAPF OVRNITE. XPCT INCRSD SHRA/TSRA ACTIVITY E COAST AFT
31/18Z AS WNDS ALOFT SW-W AND ACTIVITY WL MOV FM THE INTERIOR AND
THE E COAST DURG THE AFTN HRS. ATTM HAV ONLY VCTS IN E COAST TAFS
SEEING PSBLTY 18 HRS OUT. SFC WNDS BCMG SW AND LESS THAN 10 KTS ALL
TERMINALS THRU 18Z BUT E COAST SEA BRZE SE-SSE ARND 10 KTS TO DVLP.
PREV DISCUSSION... /ISSUED 229 PM EDT WED MAY 30 2012/
SHORT TERM (TONIGHT-FRIDAY NIGHT)...
THE LATEST NUMERICAL GUIDANCE HAS INITIALIZED WELL WITH THE
CURRENT SYNOPTIC PATTERN AND GENERALLY REMAINS IN GOOD AGREEMENT
THROUGH THE SHORT-TERM PERIOD. DESPITE THE DRIER AIR IN PLACE ACROSS
MUCH OF THE LOCAL AREA...SCATTERED AFTERNOON SHOWERS AND STORMS ARE
EXPECTED TO DEVELOP ACROSS THE EASTERN HALF OF THE LOCAL AREA
THROUGH THE EARLY EVENING PERIOD TODAY...MAINLY ACROSS THE LAKE AND
EAST COAST AREAS. THE LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL
WITH THIS PATTERN CONTINUING THROUGH THE MID-EVENING HOURS BEFORE
TRENDING DOWN THROUGH THE OVERNIGHT PERIOD TONIGHT AND INDICATES THE
BEST COVERAGE REMAINING OVER THE EASTERN AREAS NORTH OF FORT
LAUDERDALE TO THE LAKE ACROSS PALM BEACH COUNTY.
THURSDAY THROUGH FRIDAY...THE MODELS CONTINUE TO INDICATE PLENTY OF
DEEP LAYER MOISTURE SPREADING NORTH ACROSS THE KEYS INTO SOUTH
FLORIDA...WHICH HAS BEEN A PERSISTENT FEATURE OVER THE PAST COUPLE
OF DAYS FROM EACH RUN. THIS INCREASE IN DEEP LAYER MOISTURE COMBINED
WITH SOUTHWEST FLOW ALOFT AHEAD OF AN UPPER TROUGH WILL KEEP THE
RAINFALL CHANCES ELEVATED. MODEL PWAT VALUES REFLECT THIS PATTERN
AND INDICATE VALUES AROUND AND EVEN ABOVE THE TWO INCH MARK. AT THIS
TIME...TOTAL RAINFALL ACCUMULATIONS THROUGH THIS PERIOD ARE FORECAST
TO RANGE FROM 1 TO 3 INCHES NORTH OF ALLIGATOR ALLEY TO 2 TO 4
INCHES SOUTH OF ALLIGATOR ALLEY. AS TYPICALLY OBSERVED DURING THESE
EVENTS...LOCALLY HIGHER AMOUNTS WILL CERTAINLY BECOME A POSSIBILITY
WHERE THE HEAVIER ACTIVITY BECOMES CONCENTRATED. INTERESTS ARE
ENCOURAGED TO MONITOR LATER FORECASTS FOR UPDATES THROUGH THIS TIME.
AS CONFIDENCE CONTINUES TO INCREASE...A FLOOD WATCH MAY BECOME
NECESSARY.
LONG TERM (SATURDAY-TUESDAY)...
THE UPPER TROUGH IS PROGGED TO LIFT NORTHEAST ALLOWING UPPER HEIGHTS
ACROSS THE REGION TO GRADUALLY RISE. THIS COMBINED WITH MUCH DRIER
MID/UPPER LEVEL AIR SPREADING INTO THE AREA WILL LIKELY LIMIT THE
DAILY RAINFALL COVERAGE TO A MORE TYPICAL PATTERN EACH DAY.
MARINE...
LIGHT TO MODERATE SOUTH AND SOUTHWEST WINDS WILL BE EXPECTED
THROUGH THE MID-WEEK PERIOD WITH ISOLATED SHOWERS AND STORMS
REMAINING POSSIBLE EACH DAY. LATE MORNING AND AFTERNOON SEA
BREEZES WILL TRANSLATE TO CHOPPIER CONDITIONS EACH DAY...MAINLY
NEAR THE COAST.
AVIATION...
DRIER AIR HAS WORKED INTO SOUTH FLORIDA FROM THE GULF OF MEXICO
THIS MORNING...AND SHOULD REMAIN OVER SOUTH FLORIDA THROUGH REST
OF TODAY INTO TONIGHT. AT THE SAME TIME...THE EAST COAST SEA
BREEZE WILL DEVELOP AND PUSH SLOWLY INLAND THROUGH THE AFTERNOON
HOURS AND SHOULD STALL BETWEEN KMIA...KFLL...AND KTMB TAF SITES.
THIS MEANS THAT THE MOST OF THE EAST COAST TAF SITES SHOULD BECOME
SOUTHEAST BETWEEN 20Z AND 21Z TODAY...EXCEPT FOR KFXE AND KTMB
WHERE THEY WILL REMAIN SOUTHWEST. THE SPEEDS WILL ALSO BE AT 5 TO
10 KNOTS FOR REST OF THIS AFTERNOON.
THE WINDS WILL THEN SWING BACK TO A SOUTHWEST DIRECTION AFTER 00Z
TONIGHT INTO THURSDAY MORNING WITH SPEEDS AT 5 KNOTS OR LESS ALONG
THE EAST COAST TAF SITES. AT KAPF TAF SITE...THE WINDS WILL REMAIN
SOUTHWEST DIRECTION AT 5 T0 10 KNOTS EXCEPT LESS THAN 5 KNOTS TONIGHT.
THERE COULD BE SOME ISOLATED SHOWERS THIS AFTERNOON OVER MOST OF
THE TAF SITES BEFORE GOING DRY TONIGHT. THE ONLY EXCEPTION IS FOR
KPBI WHERE THERE COULD BE SOME THUNDERSTORMS THIS AFTERNOON. SO
WILL SHOW VCSH FOR ALL TAF SITES UNTIL 00Z TONIGHT...EXCEPT VCTS
FOR KPBI.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 73 83 73 / 30 30 60 50
FORT LAUDERDALE 88 74 84 77 / 40 30 60 50
MIAMI 89 74 85 76 / 50 30 60 50
NAPLES 89 74 83 74 / 40 30 60 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...47/RGH
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
254 AM CDT THU MAY 31 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
//PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PRECIPITATION TIMING AND IMPACTS TO FLIGHT CATEGORY.
* STRONG GUSTY WINDS THURSDAY AFTERNOON. BMD
//DISCUSSION...UPDATED 06Z...
SHOWERS ARE BEGINNING TO MOVE INTO NORTHERN ILLINOIS AHEAD OF UPPER
LOW TRACKING ACROSS NORTHERN IOWA. INITIAL ROUND OF SHOWERS IS
ENCOUNTERING DRY AIR LEADING TO SOME EROSION ALONG THE LEADING EDGE.
AS THE ATMOSPHERE GRADUALLY SATURATES...EXPECT COVERAGE TO INCREASE
ESPECIALLY AFTER AROUND 08Z FOR ROCKFORD AND 10Z FOR THE CHICAGO
AREA. WINDS ARE EXPECTED TO STAY OUT OF THE NORTHEAST MUCH OF THE
DAY THURSDAY...WITH GUSTS INTO THE MID TO UPPER TEENS EARLY IN THE
DAY INCREASING TO ABOVE 20 KT IN THE AFTERNOON. CIGS WILL GRADUALLY
DROP DURING THIS TIME...BUT CONFIDENCE IS NOT HIGH AT THIS POINT AS
TO HOW LOW. NAM MODEL SOUNDINGS AND MOS GUIDANCE INDICATE THAT CIGS
WILL DROP TO IFR...THOUGH GFS/MAV IS A BIT MORE RESERVED KEEPING
THINGS MVFR OR BETTER. GIVEN THE NAMS TENDENCY TO OVERDO LOW LEVEL
MOISTURE...WILL KEEP FLIGHT CATEGORY ABOVE IFR FOR NOW...BUT WILL
HAVE TO MONITOR TRENDS FOR POSSIBLY LOWER CONDITIONS. SHOWERS MAY
LINGER INTO FRIDAY MORNING WHEN THE SURFACE LOW IS PROGGED TO PULL
AWAY FROM THE REGION TAKING SHOWERS ALONG WITH IT. WINDS WILL SHIFT
BACK TO THE NNW IN THE WAKE OF THE SURFACE LOW EARLY FRIDAY MORNING
AND SHOULD THEN SEE GRADUALLY IMPROVING CONDITIONS. BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN OVERSPREADING THE TERMINALS
TONIGHT...LOW CONFIDENCE ON TIMING.
* MEDIUM TO HIGH CONFIDENCE IN CIGS DROPPING TO AT LEAST MVFR. LOW
CONFIDENCE ON CIGS DROPPING INTO IFR CATEGORY.
* MEDIUM CONFIDENCE ON WINDSPEEDS THURSDAY. BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
253 AM CDT
A POTENT LOW PRESSURE SYSTEM WILL APPROACH THE GREAT LAKES TODAY
WITH NORTHEASTERLY WINDS INCREASING TO NEAR 30 KT LATER TODAY
ACROSS THE SOUTHERN HALF OF LAKE MICHIGAN. WILL EXPAND THE SMALL
CRAFT ADVISORY TO INCLUDE THE ILLINOIS NEARSHORE WATERS BEGINNING
THIS AFTERNOON. AS THE LOW LIFTS NORTHEAST TO NEAR OHIO
TONIGHT...WINDS WILL BEGIN TO BACK TO THE NORTH...AND MAINTAIN
THEIR 30 KT MAGNITUDE WITH WAVES ACROSS THE FAR SOUTHERN PART OF
THE LAKE EXPECTED TO GROW INTO THE 7 TO 10 FT RANGE. THE LOW WILL
SLOWLY LIFT NORTH TOWARDS ONTARIO FRIDAY...BUT THE TIGHT PRESSURE
GRADIENT WILL REMAIN IN PLACE OVER LAKE MICHIGAN WITH WINDS
CONTINUING TO BACK TO THE NORTHWEST. WINDS AND WAVES SHOULD
FINALLY BEGIN TO TAPER SATURDAY NIGHT INTO SUNDAY AS THE LOW
BEGINS TO DEPART TO THE EAST. BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1234 AM CDT THU MAY 31 2012
.DISCUSSION...
917 PM CDT
HAVE INCREASED RAIN LIKELIHOOD ACROSS THE WESTERN FORECAST AREA
FOR LATE TONIGHT INTO TOMORROW MORNING...ALONG WITH SOME OTHER
MINOR TWEAKS TO WINDS AND TEMPERATURES.
THIS EVENING WATER VAPOR LOOP IS SHOWING A WELL-DEFINED NORTHERN
STREAM WAVE ABOUT TO RIDE EAST ALONG THE MN/IA BORDER. UNDER THE
HEART OF THIS WAVE...TEMPERATURES ARE PRESENTLY IN THE MID TO
UPPER 40S ACROSS EASTERN SD WITH LIGHT TO MODERATE RAIN. THIS IS
OUR UPSTREAM FLOW AND SIGN OF WHAT TOMORROW WILL BRING...WITH
PROBABLY ONLY SLIGHTLY WARMER TEMPERATURES. SEE PREV DISCUSSION
ALONG WITH CLIMATE SECTION BELOW FOR MORE INFORMATION ON THIS.
REGIONAL RAOBS REVEALED THE UPPER LEVELS MOISTENING IN ADVANCE OF
THIS SYSTEM...ALONG WITH A TIGHT WEST-TO-EAST MID-LEVEL
BAROCLINIC ZONE WITHIN THE HEIGHT FALLS SPREADING EAST. REGIONAL
RADAR SHOWS SOME DISJOINTED AREAS OF RAIN OVER SOUTHERN MN AND
IA...WITH SOME FILLING IN OCCURRING WITHIN THE PAST HALF HOUR.
THIS TREND OF INCREASING SHOWER COVERAGE BACK IN CENTRAL IA SHOULD
CONTINUE AND EXPAND EAST INTO THE OVERNIGHT AS MOISTENING
ISENTROPIC ASCENT ASSOCIATED WITH THE UPPER WAVE INCREASES. THE
MID-LEVEL CONVERGENCE IS ALSO FORECAST TO GROW INTO NORTHWEST IL
AND THEN NORTH CENTRAL IL TOWARD DAYBREAK...SERVING AS A LIKELY
FOCUS FOR RAIN. THE HRRR AND OTHER SHORT TERM/EXPLICIT MODELS
PAINT THIS GENERAL SOLUTION...THOUGH MAYBE SLIGHTLY TOO SLOW BASED
ON TRENDS TO THE WEST. ITS IN THIS EARLY TO MID MORNING TIME
WINDOW WHERE HAVE INCREASED THE POPS THE MOST ACROSS THE WEST.
WHILE THERE LIKELY WILL BE SOME MOISTURE TRANSPORT ROBBED FROM THE
WIDESPREAD SOUTHERN PLAINS/OZARKS CONVECTION OVERNIGHT...THE
DYNAMICS WITH THIS NORTHERN STREAM SYSTEM APPEAR ENOUGH TO WARRANT
NEAR 100 POPS IN THE WESTERN TO SOUTHWESTERN FORECAST AREA DURING
THE MORNING HOURS.
HAVE BUMPED UP WINDS ALONG THE LAKE SHORE THROUGH THE REMAINDER
OF TONIGHT AS SPEEDS CONTINUE TO STAY ELEVATED BASED ON AUTOMATED
AND HUMAN OBSERVATIONS FROM NEAR THE SHORE. LINEAR WEST-TO-EAST
RADAR ECHOES ADVANCING SOUTHWARD ACROSS THE SOUTHERN PART OF THE
LAKE INDICATE A POSSIBLE SECONDARY PUSH THAT SHOULD ALSO AID IN
KEEPING SPEEDS UP. TEMPERATURES WILL ACCORDINGLY CONTINUE TO DROP
WITHIN THE LOW-LEVEL COLD AIR ADVECTION...ALTHOUGH THE RATE SHOULD
SLOW QUITE A BIT OVERNIGHT AS THE CLOUD COVER THICKENS. GOING LOW
TEMPERATURES LOOK GOOD AT THIS POINT WITH ONLY SLIGHT NUDGES MADE
HERE AND THERE.
MTF
//PREV DISCUSSION...
228 PM CDT
THE MAIN FORECAST CONCERNS WILL BE RAINFALL AMOUNTS ON
THURSDAY/THURSDAY NIGHT AS A SIGNIFICANT STORM SYSTEM IMPACTS THE
AREA.
THE LATEST MODEL GUIDANCE HAS COME INTO MUCH BETTER AGREEMENT ON
THE EVOLUTION OF THE STORM SYSTEM EXPECTED TO IMPACT THE AREA
THURSDAY AND THURSDAY NIGHT. THE LATEST WATER VAPOR IMAGERY
INDICATES THE STRONG MID/UPPER LEVEL JET STREAK PUNCHING
SOUTHEASTWARD FROM SOUTHERN BRITISH COLUMBIA ACROSS THE NORTHERN
HIGH PLAINS. THE ASSOCIATED MID LEVEL SHORT WAVE IS EXPECTED TO
RAPIDLY DEEPEN INTO A CLOSED MID LEVEL CIRCULATION AS IT PUSHES
EAST SOUTHEASTWARD ACROSS THE MIDDLE AND UPPER MISSISSIPPI RIVER
VALLEY ON THURSDAY. THIS FACT ALONE INDICATES THE STRONG DYNAMIC
FORCING FOR ASCENT THAT WILL BE TAKING ACROSS THE REGION ON
THURSDAY. WITH TIME ON THURSDAY THE MID LEVEL CIRCULATION WILL
BECOME NEGATIVELY TILTED ACROSS THE WESTERN GREAT LAKES REGION. AS
THIS OCCURS...THE ASSOCIATED SURFACE LOW WILL UNDERGO RAPID
DEEPENING AND QUICKLY CONSOLIDATE AS IT TREKS NORTHEASTWARD ACROSS
THE OHIO VALLEY THURSDAY NIGHT AND EVENTUALLY NORTHWARD ACROSS THE
EASTERN GREAT LAKES ON FRIDAY. THIS A WEATHER PATTERN MORE
TYPICALLY OF THE AUTUMN SEASON.
THE NET RESULT OF THIS...WILL BE A DECENT RAINFALL
EVENT...ESPECIALLY ACROSS THE SOUTHEASTERN 1/2 TO 2/3 RDS OF MY
CWA. SOME RAIN WILL LIKELY DEVELOP ACROSS IOWA EASTWARD INTO NORTH
CENTRAL ILLINOIS AROUND OR SHORTLY BEFORE DAYBREAK ON THURSDAY AS
A BAND OF MID LEVEL FRONTOGENESIS SETS UP. DRY AIR WILL BE IN
PLACE INITIALLY ACROSS THE REGION...HOWEVER...IT APPEARS THAT THE
COLUMN WILL MOISTEN BY THURSDAY MORNING AS LARGE SCALE FORCING FOR
ASCENT INCREASES WITHIN THE ENTRANCE REGION OF A STRENGTHENING 85+
KT UPPER LEVEL JET.
IT APPEARS THE MAIN RAINFALL EVENT WILL HOLD OFF UNTIL MID TO LATE
MORNING ON THURSDAY AS THE AFOREMENTIONED DYNAMICS BEGIN TO INCREASE
ACROSS THE AREA. THE MAIN AREA OF RAINFALL LOOKS TO SHIFT SOUTHWARD
ACROSS AREAS ALONG AND SOUTH OF I-80 IN ILLINOIS DURING THE
AFTERNOON AS STRONGER MOISTURE CONVERGENCE SETS UP FARTHER SOUTH
WITHIN A DEVELOPING MID LEVEL DEFORMATION ZONE. IT APPEARS THE
RAINFALL WILL CONTINUE ACROSS MY NORTHWESTERN INDIANA COUNTIES AND
THE ADJACENT COUNTIES OF EAST CENTRAL ILLINOIS DURING THE EVENING
HOURS ON THURSDAY...BEFORE THE SYSTEM BEGINS TO SHIFT ACROSS THE
EASTERN LAKES BY FRIDAY MORNING.
ALTHOUGH THERE WILL NOT BE ANY THUNDERSTORMS...EXCEPT POSSIBLY
INTO FAR SOUTHERN BENTON COUNTY INDIANA...WITH THIS
ACTIVITY...THERE COULD BE SOME DECENT RAINFALL AMOUNTS FROM THIS
ACTIVITY...ESPECIALLY ACROSS MY SOUTHERN AND SOUTHERN CWA WHERE
PW`S WILL BE AT OR JUST ABOVE 1". RAINFALL AMOUNTS COULD EASILY BE
IN THE 1 TO 1.5 INCH AREA FOR SOME OF MY NORTHWEST INDIANA
COUNTIES. HOWEVER...MUCH LIGHTER AMOUNTS ARE EXPECTED FARTHER WEST
AND NORTH...WITH ONLY A FEW TENTHS POSSIBLE ACROSS NORTH CENTRAL
ILLINOIS.
WITH ALL OF THE CLOUDS AND PRECIPITATION AROUND...TEMPERATURES ON
THURSDAY WILL BE INCREDIBLY COLD FOR THIS TIME OF YEAR.
TEMPERATURES LOOK TO ONLY TOP OUT NEAR 50 FOR MUCH OF THE CHICAGO
AREA. THIS WILL RANK WITHIN THE COLDEST 10 PERCENT OF DAYS DURING
THE LAST WEEK OF MAY.
ONCE THE MAIN SYSTEM EXITS THE AREA ON FRIDAY THERE COULD BE A FEW
SCATTERED AFTERNOON INSTABILITY SHOWERS THAT DEVELOP ACROSS THE AREA
AS STEEP LAPSE RATES SET UP UNDER THE COLD POOL ALOFT. OTHERWISE
TEMPERATURES WILL BEGIN TO WARM ON FRIDAY...BUT WILL STILL REMAIN
VERY COOL FOR THIS TIME OF YEAR.
ANOTHER QUICK MOVING MID LEVEL DISTURBANCE LOOKS TO RACE
SOUTHEASTWARD TOWARDS THE AREA ALONG THE BACK SIDE OF THE EXITING
UPPER LEVEL LOW. THIS COULD BRING SOME MORE SHOWERS AND POSSIBLY
SOME THUNDERSTORMS TO PORTIONS OF THE AREA ON SATURDAY. IT CURRENTLY
APPEARS THE BEST CHANCES WILL BE ALONG AND SOUTH OF INTERSTATE 80.
TEMPERATURES WILL REBOUND NICELY TO NEAR 70 ON SATURDAY...WITH EVEN
WARMER TEMPERATURES WELL INTO THE 70S AND 80S EXPECTED ON SUNDAY AND
MONDAY. THIS LOOKS TO OCCUR AS THE UPPER RIDGE ACROSS THE PLAINS
STATES BUILDS EASTWARD. THE EASTWARD PUSH OF THIS RIDGE MAY BE
HINDERED...HOWEVER...AS THE GUIDANCE IS SUGGESTING THAT THE UPPER
LOW WILL REMAIN ACROSS THE NORTHEASTERN CONUS. THIS FLOW PATTERN
COULD ALLOW SOME DISTURBANCES TO RIDE SOUTHWARD ACROSS THE WESTERN
GREAT LAKES AND PUSH A BACKDOOR COLD FRONT BACK ACROSS THE AREA
EARLY NEXT WEEK. THIS MAY BRING SOME COOLER WEATHER BACK TO THE AREA
WITH ONSHORE FLOW BY THE MIDDLE OF NEXT WEEK.
KJB
&&
.CLIMATE...
917 PM CDT
HIGH TEMPERATURES ON THURSDAY WILL BE IN THE LOWEST 10 PERCENT OF
OBSERVED CLIMATOLOGY FOR NORTHERN ILLINOIS DURING THE LAST WEEK
OF MAY. THE RECORD LOW MAXIMUM TEMPERATURE FOR ROCKFORD ON MAY
31ST WILL HAVE A CHANCE TO BE BROKEN...ALTHOUGH THE CURRENT
FORECAST HIGH IS A FEW DEGREES ABOVE THIS. IF THERE IS ANY
UNCERTAINTY THOUGH...ITS A GREATER LIKELIHOOD FOR IT TO BE COOLER
THAN FORECAST AS OPPOSED TO WARMER. THE RECORD LOW MAX IS 54
DEGREES SET IN 1903. AS FOR CHICAGO...WHICH HAS A LONGER PERIOD OF
RECORD...THE RECORD LOW MAX FOR MAY 31ST IS 43 DEGREES SET IN
1889. THAT WILL NOT BE IN JEOPARDY.
MTF
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* PRECIPITATION TIMING AND IMPACTS TO FLIGHT CATEGORY.
* STRONG GUSTY WINDS THURSDAY AFTERNOON. BMD
//DISCUSSION...UPDATED 06Z...
SHOWERS ARE BEGINNING TO MOVE INTO NORTHERN ILLINOIS AHEAD OF UPPER
LOW TRACKING ACROSS NORTHERN IOWA. INITIAL ROUND OF SHOWERS IS
ENCOUNTERING DRY AIR LEADING TO SOME EROSION ALONG THE LEADING EDGE.
AS THE ATMOSPHERE GRADUALLY SATURATES...EXPECT COVERAGE TO INCREASE
ESPECIALLY AFTER AROUND 08Z FOR ROCKFORD AND 10Z FOR THE CHICAGO
AREA. WINDS ARE EXPECTED TO STAY OUT OF THE NORTHEAST MUCH OF THE
DAY THURSDAY...WITH GUSTS INTO THE MID TO UPPER TEENS EARLY IN THE
DAY INCREASING TO ABOVE 20 KT IN THE AFTERNOON. CIGS WILL GRADUALLY
DROP DURING THIS TIME...BUT CONFIDENCE IS NOT HIGH AT THIS POINT AS
TO HOW LOW. NAM MODEL SOUNDINGS AND MOS GUIDANCE INDICATE THAT CIGS
WILL DROP TO IFR...THOUGH GFS/MAV IS A BIT MORE RESERVED KEEPING
THINGS MVFR OR BETTER. GIVEN THE NAMS TENDENCY TO OVERDO LOW LEVEL
MOISTURE...WILL KEEP FLIGHT CATEGORY ABOVE IFR FOR NOW...BUT WILL
HAVE TO MONITOR TRENDS FOR POSSIBLY LOWER CONDITIONS. SHOWERS MAY
LINGER INTO FRIDAY MORNING WHEN THE SURFACE LOW IS PROGGED TO PULL
AWAY FROM THE REGION TAKING SHOWERS ALONG WITH IT. WINDS WILL SHIFT
BACK TO THE NNW IN THE WAKE OF THE SURFACE LOW EARLY FRIDAY MORNING
AND SHOULD THEN SEE GRADUALLY IMPROVING CONDITIONS. BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN RAIN OVERSPREADING THE TERMINALS
TONIGHT...LOW CONFIDENCE ON TIMING.
* MEDIUM TO HIGH CONFIDENCE IN CIGS DROPPING TO AT LEAST MVFR. LOW
CONFIDENCE ON CIGS DROPPING INTO IFR CATEGORY.
* MEDIUM CONFIDENCE ON WINDSPEEDS THURSDAY. BMD
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
* FRIDAY AND SATURDAY...CHANCE OF RAIN
* SUNDAY...VFR
* MONDAY...CHANCE OF THUNDERSTORMS
* TUESDAY...VFR
SHEA
&&
.MARINE...
411 PM CDT
LARGE HIGH PRESSURE CENTERED OVER THE NORTHERN PLAINS AND THE
UPPER MIDWEST GRADUALLY EXPANDS EASTWARD ACROSS THE GREAT LAKES
TONIGHT AND THURSDAY ALLOWING WINDS TO DIMINISH...AT LEAST
TEMPORARILY. AS LOW PRESSURE LIFTS NORTHEAST AND DEEPENS IS IT
CROSSES THE MID MISSISSIPPI VALLEY THURSDAY AFTERNOON THE
PRESSURE GRADIENT BETWEEN THE RIDGE ACROSS THE GREAT LAKES AND THE
APPROACHING LOW WILL BE ON THE INCREASE AND WILL CONTINUE TO
INCREASE THURSDAY NIGHT AS THE LOW MOVES TO NEAR WESTERN LAKE ERIE
BY FRIDAY MORNING. WINDS WILL RESPOND TO THE TIGHTENING PRESSURE
GRADIENT BY INCREASING OUT OF THE NORTH AND NORTHEAST...ESPECIALLY
ON THE SOUTH PORTION OF THE LAKE. WINDS WILL GRADUALLY BACK AND
SLACKEN LATER FRIDAY AND FRIDAY NIGHT AS THE LOW MOVES NORTH INTO
ONTARIO.
WIND AND WAVE CONDITIONS REQUIRING A SMALL CRAFT ADVISORY ARE
LIKELY FOR THE SOUTHERN PORTION OF THE ILLINOIS WATERS AND ALL OF
THE INDIANA WATERS FROM THURSDAY AFTERNOON UNTIL LATE FRIDAY.
HAZARDOUS CONDITIONS FOR SMALL CRAFT AREA ALSO LIKELY FOR THE
NORTHERN PORTION OF THE ILLINOIS WATERS THURSDAY NIGHT INTO
FRIDAY.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE NORTHERLY IS TO MICHIGAN CITY IN UNTIL 4 PM
FRIDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1002 AM CDT THU MAY 31 2012
.UPDATE...
RADAR TRENDS INDICATE THE CONVECTION HAS STRATIFORMED OUT SO THE
THREAT OF ANY TSRA ACROSS THE SOUTH THIRD OF THE CWFA HAS ENDED.
OVERALL THE FCST IS GENERALLY ON TRACK. MAX TEMPERATURES HAVE BEEN
LOWERED SLIGHTLY BASED ON READINGS UNDER THE COLD POOL YESTERDAY
AND THE EFFECT OF RAIN IN OTHER AREAS.
BASED ON CURRENT RADAR AND RAP TRENDS...TEMPERATURES WILL REMAIN
NEARLY STEADY IN THE UPPER 40S TO LOWER 50S THROUGH THE LATE
MORNING AND EARLY AFTERNOON HOURS. AS PRECIPITATION INTENSITY AND
AREAL COVERAGE DECREASES IN THE MID TO LATE AFTERNOON HOURS
TEMPERATURES WILL SLOWLY RISE. MAX TEMPERATURES WILL LIKELY OCCUR
IN THE 5 TO 7 PM TIME FRAME. AN UPDATE REFLECTING THESE CHANGES
WILL BE AVAILABLE SHORTLY. ..08..
&&
.PREV DISCUSSION... /ISSUED 652 AM CDT THU MAY 31 2012/
AVIATION...
LOW PRESSURE SYSTEM WILL MOVE ACROSS MISSOURI TODAY WITH A TROUGH
EXTENDING NORTH INTO THE REGION. THIS WILL BRING A LARGE AREA OF
RAIN ACROSS THE TERMINALS TODAY. KCID AND KDBQ ARE ALREADY IN THE
MVFR TO EVEN IFR CIGS WITH MVFR TO VFR VISIBILITIES...AND THESE
ARE EXPECTED TO SPREAD EAST TO AFFECT KMLI AND KBRL IN THE NEXT
FEW HOURS. THESE LOWERED CONDITIONS TO CONTINUE TO AFFECT THE
TERMINALS UNTIL SOMETIME THIS AFTERNOON WHEN THE PRECIPITATION AND
LOWERED VISIBILITIES WILL END FIRST. MVFR CIGS LIKELY LINGER INTO
THE EVENING...AND SOME LIGHT RAIN SHOWERS OR DRIZZLE MAY ALSO BE
POSSIBLE. CLEARING SHOULD GRADUALLY OCCUR FROM WEST TO EAST AFTER
00Z THIS EVENING. FOG IS POSSIBLE TOWARDS 12Z WITH RECENT RAINFALL
AND LIGHT WINDS. HAVE LEFT OUT OF TERMINALS FOR NOW...BUT WILL BE
CONSIDERED FOR LATER ISSUANCES. LE
PREV DISCUSSION... /ISSUED 336 AM CDT THU MAY 31 2012/
SYNOPSIS...
AN INVERTED TROUGH IS EXTENDED UP OVER THE REGION FROM A WEAK
SURFACE LOW OVER EASTERN OKLAHOMA AS OF 3 AM THIS MORNING. THIS
INVERTED TROUGH...AND THE LARGE AREA OF PRESSURE FALLS WITH IT IS ON
THE EAST SIDE OF A FAIRLY LARGE AREA OF LIGHT TO MODERATE
RAINFALL...EXTENDING FROM SOUTHERN WISCONSIN ACROSS THE NORTHERN
HALF OF THE FORECAST AREA BACK INTO SOUTHERN IOWA. AT 850MB...THERE
IS A CLOSED CIRCULATION MOVING OUT OF SOUTH DAKOTA INTO NORTHWEST
IOWA AS OF THE 00Z ANALYSIS...AND ANTICIPATE THAT BY NOW IT IS OVER
NORTHWEST IOWA. THERE IS ALSO A STRONG BAROCLINIC ZONE OVER THE
MIDWEST...WITH TEMPERATURES CHANGING FROM -1C AT KABR TO +16 AT
KTOP. THE 500MB TROUGH AND VORT MAX APPEAR TO BE RIGHT BEHIND
IT...PASSING OVER KFSD. THIS SYSTEM HAS MANY CHARACTERISTICS OF A
WINTER OR EARLY SPRING SYSTEM...AND IS STRONGLY DYNAMICALLY FORCED.
LE
SHORT TERM...TODAY AND TONIGHT...
THIS STRONGLY DYNAMICALLY FORCED SYSTEM WILL CONTINUE TO MOVE ACROSS
THE FORECAST AREA TODAY...AND OFF TO THE EAST TONIGHT. THE MAIN
AREA OF PRECIPITATION...WHICH SHOULD BE CENTERED OVER THE NORTHWEST
HALF OF THE FORECAST AREA AS OF 12Z THIS MORNING...WILL SLOWLY
ROTATE SOUTHEAST AHEAD OF THE 850MB LOW...CONTINUING THE RAIN ACROSS
MOST OF THE FORECAST AREA THIS MORNING. BY THIS AFTERNOON THE 850MB
LOW WILL BE NEAR KDBQ...AND AS THE FORCING WEAKENS WE SHOULD SEE THE RAIN
BEGINNING TO WEAKEN AND PERHAPS EVEN STOP DURING THE AFTERNOON FROM
THE NORTHWEST. HOWEVER...BY THIS EVENING THIS SYSTEM SHIFTS OFF TO
THE EAST FAIRLY QUICKLY AND WE SHOULD SEE THE RAIN STOP FROM WEST TO
EAST DURING THE LATE AFTERNOON AND EVENING HOURS. BY MIDNIGHT...I
ANTICIPATE THAT ONLY THE FAR EASTERN COUNTIES WILL STILL HAVE
RAIN...WHICH SHOULD SHUT OFF SOON AFTER. INITIALLY WE WERE THINKING
THERE WOULD BE SOME ELEVATED THUNDER THREAT WITH THIS SYSTEM ACROSS
THE SOUTH...BUT THERE HAS BEEN NO LIGHTING REPORTED OVER SOUTHERN
IOWA WHERE I WOULD HAVE EXPECTED IT TO START SHOWING UP IF IT WAS
GOING TO...SO HAVE DECIDED TO LEAVE IT OUT OF THE FORECAST FOR NOW.
THERE WILL BE SOME CONVECTIVE ELEMENTS WHICH MAY ENHANCE RAINFALL
RATES AT TIMES...BUT DO NOT EXPECT LIGHTNING TO BE A SIGNIFICANT
FACTOR WITH THIS STORM AT THIS TIME. WITH THE RAINFALL MOVING
IN...TEMPERATURES HAVE FALLEN INTO THE LOW 50S WHERE IT WAS IN THE
MID AND UPPER 50S BEFORE. EXPECT THAT TODAY IS GOING TO BE A CHILLY
MISERABLE DAY WITH THE RAIN FALLING...TEMPERATURES ONLY IN THE
50S...AND A BRISK EAST TO NORTHEAST WIND. IT IS GOING TO FEEL MORE
LIKE FALL OR EARLY SPRING THAN THE LAST DAY OF MAY. HIGHS WILL ONLY
BE IN THE MID 50S WHERE IT RAINS THE LONGEST...THOUGH SOME AREAS IN
THE WEST WHERE IT STOPS RAINING THE SOONEST MAY RISE INTO THE MID
AND EVEN UPPER 50S. THE DIURNAL RANGE TODAY IS NOT LIKELY TO BE
MUCH OVER 10 DEGREES...IF THAT. TONIGHT THE COOLER AND DRIER AIR
MOVING IN FROM THE NORTHWEST ALONG WITH THE CLEARING SKIES SHOULD
ALLOW TEMPERATURES TO FALL INTO THE 40 TO 45 DEGREE RANGE NEARLY
EVERYWHERE. LE
LONG TERM...FRIDAY THROUGH WEDNESDAY...
THE SURFACE AND UPPER LEVEL LOWS EXIT EAST INTO THE EASTERN GREAT
LAKES AND ONTARIO FRIDAY...LEAVING A NW FLOW OVER THE LOCAL AREA.
MODELS CONTINUE TO SUGGEST ONE OR MORE POSSIBLE WEAK MID LEVEL
SHORTWAVES THAT COULD PRODUCE SHOWERS IN THE NW FLOW UNTIL THE
BUILDING UPPER RIDGE OUT WEST PLACES A MORE SUBSIDENT REGIME OVER
THE AREA BY SATURDAY NIGHT.
FRIDAY...SURFACE RIDGE BUILDS INTO WESTERN IA...PROVIDING A DRY
AIRMASS ON NW WINDS OVER EASTERN IA INTO NW IL. A CONFLUENT FLOW
OVERHEAD AT 500 MB...AND THE STRONGER MID AND UPPER FLOW WELL TO THE
SW SHOULD RESULT IN A DRY DAY WITH AT LEAST PARTLY SUNNY SKIES.
MODELS SUGGEST MIXING WILL BE SUFFICIENTLY DEEP INTO THE STILL COOL
AIR ALOFT TO RESULT IN HIGHS IN THE UPPER 60S TO AROUND 70.
FRIDAY NIGHT INTO SATURDAY....WILL HAVE A POTENTIAL FOR LATE NIGHT
SHOWERS AND DAYTIME THUNDERSTORMS AS THE RIDGE AXIS OUT WEST BEGINS
TO MIGRATE EASTWARD SENDING THE MID LEVEL WAVE TRAIN OVERHEAD. THERE
CONTINUES TO BE SOME DISAGREEMENT AMONG THE MODELS AS TO WHICH
TIMEFRAME WILL SEE THE PRIMARY FORCING...SO POPS ARE KEPT IN A
SLIGHT TO LOW END CHANCE RANGE THROUGHOUT. TEMPERATURES SHOULD CONTINUE TO
MODERATE...WITH MINS IN THE 50S AND HIGHS SATURDAY INTO THE LOWER
70S.
SUNDAY THROUGH WEDNESDAY...A BLOCKY UPPER LEVEL PATTERN DEVELOPS AS
THE UPPER LEVEL RIDGE BUILDS AND SHARPENS OVER THE CENTRAL
U.S...FLANKED BY TROUGHS OVER THE COASTS. THIS SHOULD PUSH HIGHS
BACK INTO THE 80S...WHILE INCREASING GULF MOISTURE AND RISING
DEWPOINTS LIMIT MINS TO THE 60S. THERE CONTINUES TO BE A WEAK SIGNAL
TO SUGGEST A POSSIBLE MCS LATE SUNDAY NIGHT INTO MONDAY WHERE LOW
POPS ARE MAINTAINED. SHEETS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1226 AM CDT THU MAY 31 2012
...UPDATED AVIATION SECTION...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 120 PM CDT WED MAY 30 2012
THE HRRR AND RAP MODELS HAVE SHOWN A PERSISTENT CONVECTIVE
INITIATION SIGNAL ACROSS WEST CENTRAL OR SOUTHWEST KANSAS...ROUGHLY
IN AN AREA BOUNDED BY KALVESTA-GOVE-NESS CITY-KALVESTA...BY 20 TO
21Z. THIS WOULD SEEM TO MATCH THE LOCATION OF WHERE THE BOUNDARY
IS...ALTHOUGH IS A BIT FARTHER SOUTH. IT WOULD SEEM THE BEST AREA
FOR CONVECTIVE INITIATION WOULD BE JUST NORTH OF WHERE THE LATEST
HRRR RUNS HAVE IT...BUT EITHER WAY CONVECTIVE INITIATION SHOULD
OCCUR BY NO LATER THAN 22Z NORTH OF HIGHWAY 50 AND ALONG/SOUTH OF
INTERSTATE 70 IN SOUTHWEST/WEST-CENTRAL KANSAS. THE EARLY STAGE OF
CONVECTIVE MODE SHOULD BE SUPERCELLULAR WITH SURFACE-BASED CAPE
CONTINUING TO INCREASE ABOVE 3000 J/KG AND A SUBSTANTIAL AMOUNT OF
DEEP LAYER SHEAR TO SUPPORT VIGOROUS SUPERCELL THUNDERSTORMS.
SUPERCELL STORM MOTION WILL BE SOUTHEAST AT AROUND 20 TO 25 KNOTS
(NON SUPERCELL STORM MOTION BEING MORE EASTERLY). THE STORM
PREDICTION CENTER (SPC) PROBABILISTIC HAIL AND WIND ARE VERY HIGH
ACROSS MUCH OF THE DDC FORECAST AREA...INCLUDING ALL POINTS SOUTH OF
HIGHWAY 4 AND EAST OF HIGHWAY 83. THE SPC PROBABILISTIC SEVERE
WEATHER THREATS LOOK PRETTY GOOD AND AGREE ON JUST ABOUT ALL
ACCOUNTS. THE ONLY THING I QUESTION IS THE TORNADO POTENTIAL...AS
CONVECTIVE MODE AFTER A FEW HOURS MAY TRANSITION MORE TO A
QUASI-LINEAR SIGNIFICANT SEVERE EPISODE (DAMAGING TO DESTRUCTIVE
WIND POTENTIAL 80+ MPH). THIS MAY NOT OCCUR UNTIL LATER THIS
EVENING AS THE SEVERE WEATHER EVENT SHIFTS INTO OKLAHOMA. IF THE
SUPERCELL PHASE CAN LAST SEVERAL HOURS THEN THE TORNADO POTENTIAL
WILL DEFINITELY BE ENHANCED...AND FOR THAT REASON THE 10 PERCENT
TORNADO POTENTIAL (PROB OF A TORNADO WITHIN 25 MILES OF A POINT)
DOES LOOK JUSTIFIED FOR AREAS GENERALLY SOUTHEAST OF A LIBERAL TO
JETMORE TO LARNED LINE. DURING THE EVENING HOURS...THE SEVERE
WEATHER THREAT WILL DIMINISH FROM NORTH TO SOUTH AS THE MAIN AREA
SHIFTS INTO NORTHERN OKLAHOMA...HOWEVER WILL MAINTAIN SOME 20-50
POPS IN THE SOUTHEAST HALF OF THE FORECAST AREA THROUGH THE 06-09Z
TIME FRAME AS ADDITIONAL STORMS MAY DEVELOP IN THE WAKE OF THE
PRIMARY ROUND. ANYTHING DEVELOPING AFTER THE PRIMARY ROUND WILL
HAVE MUCH LESS INSTABILITY TO WORK WITH AND THE SEVERE WEATHER
THREAT SHOULD BE RATHER LOW.
THE REST OF THE FORECAST FOR LATE TONIGHT AND TOMORROW WAS
ESSENTIALLY UNCHANGED AS SUBSIDENCE AND DRIER AIR MOVES IN ON
NORTHEAST WINDS. TEMPERATURES WILL STRUGGLE TO ESCAPE THE LOWER 70S
OVER MUCH OF SOUTHWEST KANSAS ON THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 256 PM CDT WED MAY 30 2012
AFTER THE SHORTWAVE TROUGH MENTIONED IN THE SHORT TERM DISCUSSION
PASSES TO THE EAST, SURFACE HIGH PRESSURE WILL BUILD INTO WESTERN
KANSAS THURSDAY AND THURSDAY NIGHT. THURSDAY WILL BE COOLER BEHIND
THE FRONT WITH HIGHS IN THE 70S. THURSDAY NIGHT`S LOWS WILL BE FAIRLY
CHILLY IN THE 40S AS SKIES REMAIN PARTLY CLOUDY WITH FAIRLY LIGHT
SOUTHERLY WINDS. HOWEVER, IF THERE ARE MORE CLOUDS THAN CLEAR AREAS,
THEN UPPER 40S WOULD BE MORE LIKELY THAN LOWER OR MID 40S. THERE IS
A VERY SLIGHT CHANCE OF ELEVATED SHOWERS DEVELOPING TOWARD THURSDAY
MORNING AS WARM ADVECTION BEGINS IN THE ABSENCE OF SIGNIFICANT
MID-LEVEL CAPPING.
WEAK UPPER-LEVEL RIDGING IS PROGGED BY ALL THE MODELS TO DEVELOP
ACROSS THE ROCKIES BY FRIDAY AND SATURDAY AND PERSIST INTO SUNDAY,
WITH NORTHWEST TO WEST-NORTHWESTERLY MID TO HIGH-LEVEL FLOW ACROSS
THE ROCKIES. THERE WILL BE A SLIGHT MID-LEVEL DOWNSLOPE COMPONENT
ACROSS THE ROCKIES, WHICH WILL TEND TO SUPPORT SOUTHERLY WINDS AND
MOISTURE TRANSPORT INTO KANSAS. GIVEN THAT MID-LEVEL CAPPING TENDS
TO BE WEAK IN THESE REGIMES, NOCTURNAL STORM CLUSTERS COULD DEVELOP
SOMEWHERE ACROSS THE CENTRAL PLAINS IN THE MID-LEVEL BAROCLINIC
ZONE, POSSIBLY AS EARLY AS THURSDAY NIGHT(AS ALREADY MENTIONED), BUT
MORE LIKELY BY FRIDAY NIGHT. THE WARMEST TEMPERATURES FRIDAY AND
SATURDAY WILL BE IN FAR SOUTHWEST KANSAS CLOSER TO THE LEE TROUGH
WHERE HIGHS COULD REACH INTO THE UPPER 80S TO LOWER 90S, WHILE
SLIGHTLY COOLER TEMPERATURES CAN BE EXPECTED FURTHER EAST. THE MID
TO UPPER-LEVEL FLOW WILL BECOME MORE ZONAL BY SUNDAY, ALLOWING FOR
SOME LOWERING OF SURFACE PRESSURES AND WARM ADVECTION IN THE LEE OF
THE ROCKIES ALONG WITH WARMING TEMPERATURES IN THE LOWER TROPOSPHERE
ACROSS THE CENTRAL PLAINS. HIGHS COULD REACH TO BETWEEN 95 AND 100F.
A DEEP UPPER-LEVEL TROUGH WILL AMPLIFY OFF OF THE WEST COAST BY
MONDAY, WITH UPPER-LEVEL RIDGING ACROSS THE PLAINS. MONDAY SHOULD BE
FAIRLY DRY WITH HIGH AFTERNOON TEMPERATURES IN THE LOWER TO MID 90S.
ISOLATED EVENING THUNDERSTORMS CANNOT BE RULED OUT AS THE MODELS ARE
DEPICTING A WEAK SURFACE BOUNDARY CLOSE BY. THERE IS SOME
UNCERTAINTY WITH REGARDS TO THE EVOLUTION OF THE LARGE SCALE PATTERN
BY TUESDAY AND WEDNESDAY OF NEXT WEEK AND THEREAFTER. THE ECMWF AND
GEM PROGRESS THE UPPER-LEVEL TROUGH INTO CALIFORNIA/NEVADA AREA BY
WEDNESDAY WHILE THE GFS PROGRESSES THE TROUGH INTO THE NORTHERN
ROCKIES AND WESTERN CANADA. BUT ALL THREE OF THESE MODELS MAINTAIN
UPPER-LEVEL RIDGING ACROSS THE PLAINS THROUGH WEDNESDAY. HOWEVER,
THE GFS AND ECMWF SHOW PRECIPITATION IN THE MIDDLE OF THE RIDGE AXIS
EACH DAY, POSSIBLY AS A RESULT OF DAYTIME HEATING AND WEAK CAPPING.
ALSO, THE ECMWF HINTS AT A PLUME OF MID-LEVEL MOISTURE PROGRESSING
FROM THE TROPICS INTO WESTERN KANSAS, AND THIS COULD ALSO RESULT IN
PRECIPITATION EVEN IN THE UPPER-LEVEL RIDGE AXIS. DESPITE THE
UPPER-LEVEL RIDGING, AFTERNOON TEMPERATURES COULD BE HELD DOWN INTO
THE UPPER 80S TO LOWER 90S TUESDAY BY CLOUDS AND PRECIPITATION IF
THIS MOIST SCENARIO ACTUALLY PANS OUT. SEVERE WEATHER CHANCES LOOK
MINIMAL DUE TO THE WEAK WINDS THROUGHOUT THE TROPOSPHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1226 AM CDT THU MAY 31 2012
A COLD FRONT HAS PASSED THROUGH THE TAF SITES SHIFTING THE WINDS
TO THE NORTH. THE PRESSURE GRADIENT ACROSS WILL INCREASE BEHIND
THIS FRONT AS HIGH PRESSURE BUILDS INTO SOUTHWEST KANSAS
INCREASING WINDS FROM AROUND 12 KNOTS TO AROUND 20 KNOTS BY 09Z
ACROSS DDC AND GCK TERMINALS. THE HAYS TERMINAL SHOULD REMAIN
AROUND 12 KNOTS. MVFR CONDITIONS WILL ALSO BE POSSIBLE AFTER 09Z
AS STRATUS AOA020 FILTERS IN BEHIND THE AFOREMENTIONED FRONT.
CLEARING IS ANTICIPATED AFTER SUNRISE TOMORROW WITH VFR CONDITIONS
PREVAILING FOR THE REMAINDER OF THE DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 83 59 88 / 10 20 20 20
GCK 47 84 59 88 / 10 20 10 20
EHA 50 89 59 90 / 10 10 10 20
LBL 49 87 59 90 / 10 10 10 20
HYS 46 78 57 86 / 20 20 20 10
P28 48 78 59 86 / 10 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...FINCH
AVIATION...HOVORKA 42
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1155 PM CDT WED MAY 30 2012
...UPDATE TO AVIATION...
.DISCUSSION...
SHORT TERM - THROUGH THURSDAY...
19Z WATER VAPOR IMAGERY SHOWS A COMPACT SHORTWAVE DIVING SOUTHEAST
INTO SD. ELEVATED STORMS HAVE PERSISTED ACROSS CENTRAL NEB DUE TO
THIS WAVE. AT THE SFC...A WARM FRONT IS LIFTING NORTH THROUGH THE
FORECAST AREA WITH DEEPER MOISTURE ADVECTING NORTH INTO CENTRAL
AND WESTERN KS. AT 19Z THE WARM FRONT WAS NEAR OR JUST SOUTH OF
THE KS RIVER.
FOR TONIGHT...THUNDERSTORMS ARE EXPECTED TO BECOME WIDESPREAD AND
MOVE SOUTHEAST ACROSS THE AREA. THE PAST SEVERAL RUNS OF THE HIGH
RES HRRR HAVE SUGGESTED THAT AN ISOLATED STORM OR TWO MAY TRY TO
DEVELOP ON THE WARM FRONT AROUND 4 PM...THEN A LINEAR CONVECTIVE
SYSTEM MOVE ACROSS THIS EVENING. WITH THE WARM SECTOR MOVING INTO
THE AREA...INSTABILITY HAS BEEN INCREASING. MID LEVEL LAPSE RATES
ARE NEAR 8 C/KM WITH ML CAPE AS HIGH AS 2000 J/KG. SO THERE WOULD BE
ENOUGH INSTABILITY FOR STORMS TO BECOME SEVERE. IF DISCRETE STORMS
ARE ABLE TO DEVELOP THIS AFTERNOON ALONG THE WARM FRONT...THERE
COULD BE A TORNADO THREAT INITIALLY. HOWEVER LOW LEVEL SHEER IS
RATHER MARGINAL SO THIS WOULD WORK AGAINST TORNADOS. IF THE LINE OF
STORMS IS ABLE TO FORM A STRONG COLD POOL...STRONG STRAIGHT LINE
WINDS MAY BE MORE OF A CONCERN AFTER DARK IN EASTERN KS. SO WITH THE
STRONG DYNAMICS FROM THE UPPER WAVE AND INCREASING MOISTURE FROM THE
SOUTH...WILL INCREASE POPS FOR TONIGHT TO CATEGORICAL. EXPECT LOWS
TO BE FAIRLY SIMILAR TO THE PREV FORECAST WITH AROUND 50 IN THE FAR
NORTHWEST TO NEAR 60 IN THE FAR SOUTHEAST.
BY THURSDAY...THINK THAT THE BULK OF CONVECTION WILL BE MOVING EAST
OF THE AREA AS THE SHORTWAVE BEGINS TO CLOSE OFF OVER THE MID MS
RIVER VALLEY. MODELS INDICATE THERE IS STILL SOME PV ANOMALIES
MOVING AROUND THE BACK SIDE OF THE UPPER WAVE ALONG THE MO RIVER.
ALTHOUGH MUCH IF NOT ALL OF THE INSTABILITY SHOULD BE SHIFTED TO THE
EAST. SO THERE MAY BE SOME PRECIP LINGER ACROSS NORTHEAST KS DURING
THE DAY. BUT WOULD EXPECT THAT TO BE MAINLY SHOWERS. THERE COULD BE
SOME INSOLATION THURSDAY...ESPECIALLY ACROSS NORTH CENTRAL KS AND
WITH THE MODELS TENDED TO BE A LITTLE COOL THE PAST COUPLE
DAYS...HAVE BUMPED UP HIGHS TO THE UPPER 60S AND AROUND 70 IN NORTH
CENTRAL AND EAST CENTRAL KS AND THE MID 60S NORTHEAST WHERE CLOUD
COVER AND PRECIP CHANCES SHOULD BE HIGHER.
WOLTERS
MID TERM - THURSDAY NIGHT THROUGH SATURDAY...
THERE ARE TWO PRIMARY WEATHER STORIES IN THE MID TERM. THE FIRST
SURROUNDS A CHILLY START TO FRIDAY MORNING. A COOL AIRMASS WILL
SETTLE OVERHEAD WHILE SURFACE HIGH PRESSURE DRIFTS ACROSS EASTERN
KANSAS. EXPECT MOST CLOUD COVER TO HOLD OFF UNTIL AFTER SUNRISE SO
THE COMBINATION OF LIGHT WINDS...CLEAR SKIES...AND A COOL AIRMASS
SHOULD LEAD TO MORNING LOWS IN THE MIDDLE 40S. ANY UNCERTAINTY IN
THIS COLD FORECAST WOULD REST WITH CLOUD COVER POTENTIAL AS ANY MID
CLOUDS MOVING IN FROM THE WEST WOULD RESULT IN A SHARP JUMP IN LOW
TEMPS UNDER THE CLOUDS.
THE OTHER FOCUS DURING THE MID TERM IS ON RAIN CHANCES FRIDAY INTO
FRIDAY NIGHT. A CLOSED UPPER TROUGH WILL REMAIN NEARLY STATIONARY
OVER THE GREAT LAKES ON FRIDAY WHILE A SHORT WAVE TROUGH WILL PASS
THROUGH NEBRASKA AND EASTERN KANSAS ON THE BACK SIDE OF THE MAIN
SYSTEM. IT APPEARS THAT THERE WILL BE AN ENHANCED ZONE OF
ISENTROPIC ASCENT ACROSS THE AREA ALONG A MID LEVEL FRONTAL
BOUNDARY LOOSELY ASSOCIATED WITH THIS SHORT WAVE. THE ADDITION OF
WEAK UPPER LEVEL ASCENT ASSOCIATED WITH THE WAVE AND A VERY WEAK
SURFACE COLD FRONT SHOULD LEAD TO ISOLATED TO SCATTERED SHOWERS
WITH A THUNDERSTORM OR TWO POSSIBLE. THE BEST PRECIP CHANCES
APPEAR TO COME LATE FRIDAY AFTERNOON INTO EARLY SATURDAY
MORNING...AND DO NOT EXPECT MUCH MORE THAN SCATTERED LIGHT TO
MODERATE RAIN.
A WARMING TREND WILL BEGIN FOR SATURDAY WITH SOME WARM AIR
ADVECTION ALOFT AND PLENTY OF SUNSHINE BRINGING HIGHS INTO THE
80S.
BARJENBRUCH
LONG TERM - SUNDAY THROUGH WEDNESDAY...
A LONG WAVE TROUGH AXIS WILL SET UP ACROSS THE EASTERN HALF OF THE
CONUS WHILE LONG WAVE RIDGING GRADUALLY INCREASES ACROSS THE
ROCKIES AND HIGH PLAINS. EXPECT THE LOCAL FORECAST AREA TO BE IN A
BIT OF A PINCH POINT BETWEEN THE TROUGH AND RIDGE THROUGH THE
FIRST PART OF THE EXTENDED PERIOD WITH EPISODES OF ENHANCED LIFT
ACROSS THE AREA AS WARM ADVECTION ATTEMPTS TO SURGE NORTH OVER A
WEAK STATIONARY FRONTAL BOUNDARY DRAPED ACROSS KANSAS. THUS...IT
WILL BE A FAIRLY UNSETTLED PERIOD WITH OCCASIONAL CHANCES FOR
THUNDERSTORMS BOTH DURING THE PEAK HEATING HOURS AS WELL AS SOME
POTENTIAL FOR OVERNIGHT MCS ACTIVITY. THE BEST CHANCE FOR
WIDESPREAD PRECIP APPEARS TO COME SUNDAY NIGHT AS A SHORT WAVE
TROUGH MOVES OVER THE RIDGE AND ACROSS THE REGION. THE BEST CHANCE
FOR DRY WEATHER APPEARS TO COME MONDAY THROUGH TUESDAY AS SLIGHTLY
DRIER AIR MOVES IN...BUT THUNDERSTORM CHANCES COME BACK INTO THE
FORECAST BY THE MIDDLE OF NEXT WEEK AS A TROUGH DEEPENS OVER THE
ROCKIES AND MOISTURE PUSHES BACK NORTH INTO THE AREA.
TEMPERATURES WILL BE WARM...LIKELY IN THE 90S AT TIMES...BUT WILL
ALSO BE HIGHLY DEPENDENT UPON CLOUD COVER. ANY SUNNY DAYS IN THE
LONG TERM WILL LIKELY RESULT IN HIGHS AT LEAST IN THE LOWER 90S
WHILE LOW TEMPS MOST NIGHTS SHOULD BE IN THE UPPER 60S TO AROUND
70.
BARJENBRUCH
&&
.AVIATION...
TIMING AND HEIGHTS OF STRATUS DECK ARE THE MAIN CONCERNS FOR THIS
FORECAST. CIGS ON IFR/MVFR BORDER COMING SOUTHEAST FROM EASTERN
NEBRASKA SHOULD REACH THE TERMINALS IN THE 9-12Z PERIOD BASED ON
TRENDS...THOUGH GUIDANCE IS A BIT QUICKER. WILL GO WITH OBS AT
THIS POINT. GIVEN UPSTREAM AND GUIDANCE AGREEMENT...EXPECT A FEW
HOURS OF IFR CIGS BEFORE RISING TO VFR AROUND 16Z.
65
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
251 AM EDT THU MAY 31 2012
.UPDATE...
ISSUED AT 728 PM EDT WED MAY 30 2012
PERSISTENT CLOUDS CONTINUE TO SLOWLY DIMINISH OVER THE CWA THIS
EVENING. THEY HAVE BEEN THE THICKEST OVER THE WCNTRL/SCNTRL PORTION
OF THE AREA AND MAY EVEN BE PRODUCING A FEW SPRINKLES OVER NRN
MENOMINEE COUNTY. RAP RUNS CONTINUE TO HAVE THE BEST HANDLE ON THESE
CLOUDS ON THE 0.5-1KM LAYER AND WITH THE LOSS OF DIURNAL
HEATING...EXPECT THEM TO QUICKLY DIMINISH WHILE PUSHING S. DID DELAY
THE EXIT CLOSER TO MIDNIGHT OVER THE SCNTRL.
WITH THE CLOUDS DIMINISHING AND COOL DRY AIR IN PLACE...PWAT VALUES
AROUND 35 PERCENT OF NORM...EXPECT TEMPS TO QUICKLY FALL AFTER
SUNSET WHERE SKIES ARE CLEAR. HAVE SOME CONCERN THAT THE INITIAL
CLEAR SKIES OVER THE EAST WILL ALLOW SOME OF THE TRADITIONAL COLD
SPOTS TO NEAR FREEZE WARN CRITERIA...28 DEGREES FOR 3HRS. BUT
LINGERING WINDS ALOFT MAY PROVIDE JUST ENOUGH MIXING TO KEEP TEMPS
AT OR SLIGHTLY ABOVE. THUS...WILL LEAVE HEADLINES AS IS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
CURRENTLY...THERE IS AN UPPER TROUGH DRAPED N OF THE CWA...WITH SFC
RIDGING PUSHING IN FROM THE W. NW LOW LEVEL WINDS COMBINED WITH
LINGERING LOW LEVEL MOISTURE AND COOLER 850MB TEMPS AROUND -2C HAS
LEAD TO CLOUDS OVER THE AREA TODAY...BUT THE CLOUD COVER IS AND WILL
CONTINUE TO DIMINISH THROUGH THIS AFTERNOON AND EVENING. THE UPPER
TROUGH WILL MOVE TO THE CENTER OF THE CWA BETWEEN 12Z AND 18Z
THU...WITH THE SFC RIDGE MOVING FARTHER INTO THE CWA THROUGH THE
NIGHT. THIS LEADS TO CLEARING SKIES AS MUCH DRIER AIR MOVES
OVERHEAD...SO TEMPS WILL BE COLD TONIGHT SEEING AS HOW HIGH TEMPS
LATE THIS AFTERNOON INTO THIS EVENING WILL BE IN THE MID 40S TO MID
50S. EXPECT WIDESPREAD FROST OVER ALL BUT THE KEWEENAW
PENINSULA...MAINLY INLAND FROM THE GREAT LAKES WHERE TEMPS WILL FALL
INTO THE UPPER 20S...COLDEST OVER THE INTERIOR WEST AND CENTRAL.
THE SWRN EXTENT OF THE UPPER TROUGH DEEPENS OVER SW WI BY 00Z FRI IN
RESPONSE TO AN UPPER JET MOVING IN FROM THE NRN PLAINS. AT THE SAME
TIME...A W-E ORIENTED UPPER RIDGE WILL PUSH TO FAR NRN LAKE
SUPERIOR. HOWEVER...MOST OF THE CLOUDS AND ALL OF THE PRECIP FROM
THIS SYSTEM AS IS STRENGTHENS WILL STAY S OF THE CWA THU. 850MB
TEMPS WILL INCREASE TO A CWA AVG VALUE OF AROUND 5C BY 00Z
FRI...WHICH WILL ALLOW FOR WARMER HIGH TEMPS IN THE 50S NEAR LAKE
SUPERIOR...AND IN THE 60S INLAND.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 439 PM EDT WED MAY 30 2012
IN THE LONGER TERM...INITIAL FOCUS OF FCST WILL BE ON RAIN POTENTIAL
FRI/SAT AS SYSTEM LIFTS THRU LWR MI...POSSIBLY BRUSHING THE FCST
AREA WITH RAIN SHIELD. FARTHER DOWN THE LINE...PATTERN SHOULD
OVERALL SUPPORT DRY WEATHER AS MID/UPPER RIDGE BUILDS THRU CNTRL
NAMERICA.
BEGINNING THU NIGHT...SHORTWAVE DROPPING INTO THE MIDWEST WILL
DEEPEN INTO A MIDLEVEL LOW CENTERED VCNTY OF CHICAGO BY FRI MORNING.
UPPER MI REMAINS UNDER SFC RIDGING N OF SYSTEM...SO DRY WEATHER IS
EXPECTED THU NIGHT. SHOULD SEE AN INCREASE IN HIGH CLOUDS EXPANDING
N FROM THE ORGANIZING SYSTEM TO THE S. NONETHELESS...LIGHT/CALM WIND
AND PRECIPITABLE WATER 40-60PCT OF NORMAL SUGGEST FAVORING THE LOWER
END OF GUIDANCE. FROST MAY BE AN ISSUE IN THE TYPICAL COLD SPOTS...
DEPENDING ON HOW QUICKLY HIGH CLOUDS INCREASE.
SYSTEM ORGANIZING TO THE S THU NIGHT WILL TRACK THRU THE GREAT LAKES
REGION FRI/SAT. AFTER SHOWING A NW TREND TO SYSTEM YESTERDAY...
MODELS HAVE SETTLED TOWARD A MID LEVEL LOW TRACK ACROSS LWR MI AND
TOWARD JAMES BAY. TRACK IS FAR ENOUGH TO THE E THAT ONLY THE ERN
FCST AREA MAY GET BRUSHED BY ITS PCPN SHIELD FRI INTO SAT. AT THIS
POINT...CHC POPS STILL LOOK ON TRACK...BUT WILL TRIM WRN EXTENT OF
POPS E TO ROUGHLY A MUNISING/MENOMINEE LINE.
SUN THRU WED...MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST AN
AMPLIFYING CNTRL NAMERICA RIDGE NEXT WEEK AS A RIDGE OVER THE
ROCKIES THIS WEEKEND DRIFTS E AND MERGES WITH A POSITIVE ANOMALY
RETROGRADING FROM THE DAVIS STRAIT. A TROF WILL BE SITUATED OVER THE
WRN CONUS WITH A DEEPER TROF OVER THE NE. RESULT WILL BE NWRLY FLOW
GRADUALLY BECOMING NRLY BY THE MIDDLE OF THE WEEK AS RIDGE SHARPENS
JUST TO THE W. PATTERN SHOULD TEND TO FAVOR DRIER CONDITIONS HERE
WITH BUILDING MIDLEVEL RIDGE TO THE W AND NW SUPPORTING SFC HIGH
PRES GRADUALLY EXPANDING S FROM NCNTRL CANADA/HUDSON BAY INTO THE
GREAT LAKES REGION. HOWEVER...SUMMERTIME NWRLY FLOW CAN OFTEN LEAD
TO SCT DIURNAL CONVECTION WITH ANY MINOR SHORTWAVE PROGRESSING THRU
THE FLOW. TO SOME EXTENT...MEDIUM RANGE GUIDANCE OVER THE LAST FEW
DAYS HAS SUGGESTED THAT POTENTIAL. ALTHOUGH NOT WELL AGREED UPON...
THERE HAS BEEN A SIGNAL IN RECENT DAYS FOR A SHORTWAVE TO PASS THRU
THE AREA MON...SO FCST WILL CONTINUE TO INCLUDE LOW POPS LATE SUN
INTO MON. LATEST MODEL RUNS APPEAR TO BE TRENDING AWAY FROM THIS
SHORTWAVE CUTTING THRU THE BUILDING RIDGE AND INTO THE UPPER
LAKES...SO POPS HAVE BEEN DROPPED MOSTLY TO SLIGHT CHC. BEYOND
MON...SINCE THE EXPECTED PATTERN DOES NOT FAVOR ORGANIZED PCPN
EVENTS...PLAN TO KEEP FCST ON THE DRY SIDE GIVEN THE VERY LOW
PREDICTABILITY AT THIS TIME RANGE OF ANY MINOR SHORTWAVES AND
ASSOCIATED POTENTIAL SCT PCPN. WITH SFC HIGH PRES SLOWLY BUILDING S
FROM NRN CANADA...THERE SHOULD BE A WIND COMPONENT OFF LAKE SUPERIOR
MOST DAYS TO KEEP LAKESIDE LOCATIONS ON THE COOLER SIDE. INLAND...
TEMPS SHOULD BE NEAR TO SLIGHTLY ABOVE NORMAL FOR EARLY JUNE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 251 AM EDT THU MAY 31 2012
HIGH PRESSURE OVER THE UPPER GREAT LAKES WILL KEEP LIGHT/VRB WINDS
AND VFR CONDITIONS THROUGH THE TAF PERIOD. MODELS SHOW HIGH CLOUDS
DEVELOPING OVER INLAND AREAS /KIWD AND KSAW/...BUT WITH SIGNIFICANT
DRY AIR IN PLACE...ONLY WENT WITH SCATTERED DECK.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 439 PM EDT WED MAY 30 2012
GUSTY WINDS WILL CONTINUE TO DIMINISH FROM W TO E THIS EVENING AS
HIGH PRES BUILDS INTO THE UPPER LAKES. BY LATE TONIGHT...WINDS WILL
BE UNDER 15KT. WINDS WILL REMAIN MOSTLY UNDER 15KT THRU THU AND INTO
FRI AFTN. WINDS MAY INCREASE A LITTLE FRI NIGHT AND SAT OVER EASTERN
LAKE SUPERIOR AS LOW PRES MOVES NE THRU THE CNTRL GREAT LAKES
REGION. OTHERWISE...WINDS WILL GENERALLY REMAIN ON THE LIGHT SIDE
INTO THE WEEKEND.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
FROST ADVISORY UNTIL 8 AM EDT /7 AM CDT/ THIS MORNING FOR MIZ002-
004>007-009>014-084-085.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...SRF
SHORT TERM...TITUS
LONG TERM...ROLFSON
AVIATION...JMW
MARINE...TITUS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1258 PM CDT THU MAY 31 2012
.UPDATE...
ISSUED AT 1108 AM CDT THU MAY 31 2012
SHOWERS...ALONG WITH SCATTERED THUNDERSTORMS...WILL PERSIST ALONG
AND ESPECIALLY EAST OF THE MISSISSIPPI RIVER INTO THE MID
AFTERNOON HOURS. ALTHOUGH THERE HAS BEEN A DEFINITE EWD PUSH TO
THE BACK EDGE OF THE RAIN AREA...EXPECTING ADDITIONAL DEVELOPMENT
TO OCCUR AS SHORTWAVE OVER NW MO DIGS INTO MID MISSISSIPPI VALLEY.
IT STILL APPEARS THAT ANY SEVERE WEATHER POTENTIAL WILL BE
CONFINED TO A VERY NARROW WINDOW OF OPPORTUNITY IN OUR FAR SE
COUNTIES. PROPAGATION OF SURFACE BOUNDARY...ALONG WITH CURRENTLY
RAIN-COOLED AIRMASS IN OUR SE...CERTAINLY SUGGESTS THE GREATER
THREAT WILL BE EAST OF OUR CWA.
TEMP TRENDS STILL LOOKING REASONABLE...ALTHOUGH DID HAVE TO UP
MAX TEMPS OVER MID MO AS BREAK IN THE CLOUDS HERE HAS ALLOWED
TEMPS TO JUMP INTO THE LOWER 70S. THIS WARMUP SHOULD BE FAIRLY
BRIEF...AS CLOUDS AND CAA WILL DROP TEMPS BACK INTO THE 60S FOR
MUCH OF THE AFTERNOON.
TRUETT
&&
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 1235 PM CDT THU MAY 31 2012
FA WILL CERTAINLY BE EXPEREINCING ATYPICAL AVIATION CONDITIONS
FOR LATE MAY AND EARLY JUNE OVER THE NEXT 12-18 HOURS. SURFACE LOW
IS APPROACHING STL AREA ATTM...WITH SCT-BKN CLDS BTWN 1500-2000
FEET IN THE PROXIMITY OF THE LOW. MEANWHILE...A MUCH MORE
EXTENSIVE AREA OF MVFR...AND OCNL IFR...CIGS LOCATED TO THE N AND
NW OF THE LOW. THIS CLOUD DECK SHOULD PERSIST INTO THE EARLY
EVENING AT BOTH COU AND UIN...AND IS EXPECTED TO ROTATE INTO THE
STL BY MID AFTERNOON AS THE SURFACE LOW PUSHES INTO IL. STILL
EXPECTING SPOTTY SHOWERS ALONG THE MISSISSIPPI RIVER THIS
AFTERNOON...WITH THE THREAT OF STRONGER CONVECTION FOCUSED TO THE
SE OF THE STL AREA. 12Z MOS OUTPUT...AS WELL AS 12Z FORECAST
SOUNDINGS...ARE STILL STRONGLY SUGGESTING WIDESPREAD IFR CIGS
DEVELOPING EARLY THIS EVENING. AS MENTIONED AT THE START OF THE
AFD THIS WOULD BE HIGHLY UNUSUAL...BUT GIVEN THE UNSEASONAL NATURE
OF THIS SYSTEM TREND SEEMS REASONABLE. DRIER AIR ADVECTING INTO
THE BACK SIDE OF THE SURFACE SYSTEM SHOULD SLOWLY ERODE THIS LOWER
DECK LATE TONIGHT AND EARLY FRIDAY MORNING...MODELS DO NOT HAVE A
GOOD HANDLE ON THIS TREND SO FORECAST REPRESENTS A VERY FIRST
ROUGH APPROXIMATION ON WHEN CLEARING MAY OCCUR.
SPECIFICS FOR KSTL...
AS MENTIONED ABOVE...SCT-BKN CU/CUFRA WILL GIVE WAY TO A MORE
EXTENSIVE AREA OF MVFR CIGS...WITH CIGS BETWEEN 1500-2000 FT
BECOMING COMMON FROM MID/LATE AFTERNOON INTO EARLY EVENING. MOS
AND FORECAST SOUNDINGS THEN SUGGEST THAT THESE CIGS WILL LOWER
BELOW 1KFT DURING THE EVENING...WITH THESE IFR CIGS THEN
PERSISTING INTO EARLY FRIDAY MORNING. LOOKS LIKE THE MOST ROBUST
CONVECTION THIS AFTERNOON WILL OCCUR/REDEVELOP JUST TO THE SE OF
THE AREA...WITH GENERALLY SPOTTY LIGHT SHRA IN THE STL TAF VICINITY.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1119 AM CDT THU MAY 31 2012
.UPDATE...
ISSUED AT 1108 AM CDT THU MAY 31 2012
SHOWERS...ALONG WITH SCATTERED THUNDERSTORMS...WILL PERSIST ALONG
AND ESPECIALLY EAST OF THE MISSISSIPPI RIVER INTO THE MID
AFTERNOON HOURS. ALTHOUGH THERE HAS BEEN A DEFINITE EWD PUSH TO
THE BACK EDGE OF THE RAIN AREA...EXPECTING ADDITIONAL DEVELOPMENT
TO OCCUR AS SHORTWAVE OVER NW MO DIGS INTO MID MISSISSIPPI VALLEY.
IT STILL APPEARS THAT ANY SEVERE WEATHER POTENTIAL WILL BE
CONFINED TO A VERY NARROW WINDOW OF OPPORTUNITY IN OUR FAR SE
COUNTIES. PROPAGATION OF SURFACE BOUNDARY...ALONG WITH CURRENTLY
RAIN-COOLED AIRMASS IN OUR SE...CERTAINLY SUGGESTS THE GREATER
THREAT WILL BE EAST OF OUR CWA.
TEMP TRENDS STILL LOOKING REASONABLE...ALTHOUGH DID HAVE TO UP
MAX TEMPS OVER MID MO AS BREAK IN THE CLOUDS HERE HAS ALLOWED
TEMPS TO JUMP INTO THE LOWER 70S. THIS WARMUP SHOULD BE FAIRLY
BRIEF...AS CLOUDS AND CAA WILL DROP TEMPS BACK INTO THE 60S FOR
MUCH OF THE AFTERNOON.
TRUETT
&&
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 606 AM CDT THU MAY 31 2012
LARGE AREA OF SHRA/TSRA OVER S CNTRL MO WILL CONTINUE TO MOVE EWD OVER
THE NEXT FEW HOURS. THE NORTHERN EDGE OF THIS MASS WILL PASS CLOSE
ENOUGH TO THE ST. LOUIS METRO AREA TAF SITES THROUGH 14Z TO
WARRANT EITHER VCSH OR A SHORT TEMPO GROUP FOR VFR -SHRA. RADAR IS
SHOWING A GRADUAL INCREASE IN AREAL COVERAGE OR SHRA/SCT TSRA FROM
NERN MO SWWD INTO W CNTRL MO THE PAST COUPLE OF HOURS IN RESPONSE
TO DEEPENING TROUGH OVER THE CENTRAL PLAINS. EXPECT THIS AREA TO
CONTINUE TO INCREASE IN SIZE AND MOVE EWD THROUGH THE MORNING.
HAVE INCLUDED ABOUT 4 HOURS OF -SHRA AT ALL OF THE TAF SITES THIS
MORNING/EARLY AFTERNOON TO ACCOUNT FOR A FAIRLY WIDESPREAD
COVERAGE OF RAIN DURING THIS PERIOD. INITIAL VFR CONDITIONS WILL
DECREASE TO MVFR WITH THE RAIN...WITH CIGS BECOMING MVFR/IFR AS
AREA OF LOW CIGS CURRENTLY OVER WRN IA/ERN NE/NERN KS MOVES SEWD
INTO THE AREA. THESE LOW CLOUDS WILL REMAIN OVER THE AREA UNTIL
TONIGHT WHEN THEY WILL BEGIN TO CLEAR OUT FROM WEST TO EAST.
SURFACE LOW OVER SW MO WILL MOVE ACROSS SRN MO CAUSING CURRENT
ELY WINDS TO BACK NWLY THIS MORNING AT ALL OF THE TAF SITES.
SPECIFICS FOR KSTL...MAY SEE SOME VFR -SHRA AT THE TERMINAL THROUGH
13Z ALONG NRN EDGE OF LARGE MASS OF -SHRA/-TSRA MOVES THROUGH SRN
MO. WILL LIKELY SEE -SHRA BETWEEN 16-20Z AS AREA OF RAIN FILLS IN
OVER THE NEXT FEW HOURS OVER WRN AND CNTRL MO THE NEXT FEW HOURS
AND MOVES EWD. CIGS WILL DECREASE FROM VFR TO MVFR AS THE RAIN
MOVES THROUGH...AND THEN REMAIN MVFR/POSSIBLY IFR AT TIMES LATE
THIS AFTERNOON AND EVENING AFTER THE RAIN EXITS THE REGION. VFR
CONDITIONS SHOULD RETURN AFT 06Z AS CLOUDS MOVE OUT OF THE AREA.
SFC WINDS WILL BACK FROM ELY TO NWLY QUICKLY BETWEEN 17-20Z AS
SFC LOW PASSES TO THE SOUTH.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
642 AM CDT Thu May 31 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Short Range (Thursday through Saturday)
Bulk of shower and thunderstorm activity appears to be splitting the
forecast area this morning. MCS over southwest Missouri should
continue general eastward progression, while shower activity associated
with deepening upper level trough so far has mainly been confined to
north of the Missouri-Iowa state line. Short range HRRR model has
been persistent this morning in filling area of precipitation in over
northern Missouri and it appears to be materializing with the last
few radar volume scans over northern central Missouri.
Surface low currently located over northeast Oklahoma forecast to
push northeast across southern Missouri today as decent cold air
advection sets in behind the system. Still anticipating a good deal
of cloud cover across the region today, however given current radar
trends will lower PoPs especially over the western 2/3 of forecast
area. There may be some clearing this afternoon over the western
part of the forecast area, however model soundings seem to hint at
bringing some additional cloud cover back into the region after
sunset. Will refine with later forecasts, but this could have an
impact on morning low temperatures on Friday.
With surface high pressure dominating the weather on Friday,
depending on morning cloud cover, should see chilly start with
temperatures in the 40s at most locations. In the meantime upper
level trough becomes established over the Great Lakes putting
forecast area in northwest flow pattern. Some indications that weak
low-level warm advection and isentropic ascent set up for Friday
night into Saturday morning. This could interact with subtle
shortwave/speed max rotating through mean trough over the Great Lakes
to provide for some elevated convection. At this time though it
appears best chance for activity would remain north and east of
forecast area so have trimmed PoPs a bit to into the slight chance
category.
MJM
Medium Range (Sunday through Wednesday)...
Later half of the forecast arrives Sunday with conditions across the
Central Plains warming back up after a few days of below to near
normal temperatures. The pattern across the nation Sunday will begin
rather benignly as it will still be relatively flat, though that
will quickly change as a trough shifts onshore across the Pacific
Coast, with a corresponding amplification of a ridge across the
Plains States. This amplification will bring above normal
temperatures back to the region, which should then prevail through
at least the first half of the work week.
Some focus will be needed for POPs late in the weekend and into the
beginning of the work week. Verity of mid-range models are
advertising a shortwave crossing the ridge axis Sunday, which
generates precipitation across our neck-of-the-woods Sunday and
Sunday night, with some models lingering precipitation into the day
Monday. Confidence on the specifics of the shortwave (like timing
and location) are fairly low, but given the nocturnal environment
that the expanding ridge will bring to the Plains, thoughts are this
shortwave my spawn a MCS Sunday night. Have limited chance POPs to
the overnight hours of Sunday with this expectation. Otherwise,
models also have a smattering of slight chance POPs in the coming
work week, but the output seems to suggest that they are having
issues with the generally warm and moist environment present under
the ridge. So, have trimmed much of the slight chance POPs from the
days after Monday.
Cutter
&&
.AVIATION...
For the 12Z TAFs...Low end MVFR clouds have spread south into the
terminals this morning in the cool air behind last night convective
system. Clouds are expected to lift and break up later this morning,
leaving VFR conditions to prevail through the rest of the daylight
hours. As clouds scatter later this morning, gusty winds will onset
from the north as boundary layer mixing ramps up. Gusty winds will
calm as the sun sets this evening. Otherwise, models indicate that
some low ceilings will rotate south across the terminals again
tonight. Confidence is not high enough to bite on the model guidance
that MVFR, and especially the sub-MVFR, ceilings will be moving in,
so have limited them in at 4000ft for tonight.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
607 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 606 AM CDT THU MAY 31 2012
LARGE AREA OF SHRA/TSRA OVER S CNTRL MO WILL CONTINUE TO MOVE EWD OVER
THE NEXT FEW HOURS. THE NORTHERN EDGE OF THIS MASS WILL PASS CLOSE
ENOUGH TO THE ST. LOUIS METRO AREA TAF SITES THROUGH 14Z TO
WARRANT EITHER VCSH OR A SHORT TEMPO GROUP FOR VFR -SHRA. RADAR IS
SHOWING A GRADUAL INCREASE IN AREAL COVERAGE OR SHRA/SCT TSRA FROM
NERN MO SWWD INTO W CNTRL MO THE PAST COUPLE OF HOURS IN RESPONSE
TO DEEPENING TROUGH OVER THE CENTRAL PLAINS. EXPECT THIS AREA TO
CONTINUE TO INCREASE IN SIZE AND MOVE EWD THROUGH THE MORNING.
HAVE INCLUDED ABOUT 4 HOURS OF -SHRA AT ALL OF THE TAF SITES THIS
MORNING/EARLY AFTERNOON TO ACCOUNT FOR A FAIRLY WIDESPREAD
COVERAGE OF RAIN DURING THIS PERIOD. INITIAL VFR CONDITIONS WILL
DECREASE TO MVFR WITH THE RAIN...WITH CIGS BECOMING MVFR/IFR AS
AREA OF LOW CIGS CURRENTLY OVER WRN IA/ERN NE/NERN KS MOVES SEWD
INTO THE AREA. THESE LOW CLOUDS WILL REMAIN OVER THE AREA UNTIL
TONIGHT WHEN THEY WILL BEGIN TO CLEAR OUT FROM WEST TO EAST.
SURFACE LOW OVER SW MO WILL MOVE ACROSS SRN MO CAUSING CURRENT
ELY WINDS TO BACK NWLY THIS MORNING AT ALL OF THE TAF SITES.
SPECIFICS FOR KSTL...MAY SEE SOME VFR -SHRA AT THE TERMINAL THROUGH
13Z ALONG NRN EDGE OF LARGE MASS OF -SHRA/-TSRA MOVES THROUGH SRN
MO. WILL LIKELY SEE -SHRA BETWEEN 16-20Z AS AREA OF RAIN FILLS IN
OVER THE NEXT FEW HOURS OVER WRN AND CNTRL MO THE NEXT FEW HOURS
AND MOVES EWD. CIGS WILL DECREASE FROM VFR TO MVFR AS THE RAIN
MOVES THROUGH...AND THEN REMAIN MVFR/POSSIBLY IFR AT TIMES LATE
THIS AFTERNOON AND EVENING AFTER THE RAIN EXITS THE REGION. VFR
CONDITIONS SHOULD RETURN AFT 06Z AS CLOUDS MOVE OUT OF THE AREA.
SFC WINDS WILL BACK FROM ELY TO NWLY QUICKLY BETWEEN 17-20Z AS
SFC LOW PASSES TO THE SOUTH.
BRITT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
403 AM CDT Thu May 31 2012
.DISCUSSION...
Short Range (Thursday through Saturday)
Bulk of shower and thunderstorm activity appears to be splitting the
forecast area this morning. MCS over southwest Missouri should
continue general eastward progression, while shower activity associated
with deepening upper level trough so far has mainly been confined to
north of the Missouri-Iowa state line. Short range HRRR model has
been persistent this morning in filling area of precipitation in over
northern Missouri and it appears to be materializing with the last
few radar volume scans over northern central Missouri.
Surface low currently located over northeast Oklahoma forecast to
push northeast across southern Missouri today as decent cold air
advection sets in behind the system. Still anticipating a good deal
of cloud cover across the region today, however given current radar
trends will lower PoPs especially over the western 2/3 of forecast
area. There may be some clearing this afternoon over the western
part of the forecast area, however model soundings seem to hint at
bringing some additional cloud cover back into the region after
sunset. Will refine with later forecasts, but this could have an
impact on morning low temperatures on Friday.
With surface high pressure dominating the weather on Friday,
depending on morning cloud cover, should see chilly start with
temperatures in the 40s at most locations. In the meantime upper
level trough becomes established over the Great Lakes putting
forecast area in northwest flow pattern. Some indications that weak
low-level warm advection and isentropic ascent set up for Friday
night into Saturday morning. This could interact with subtle
shortwave/speed max rotating through mean trough over the Great Lakes
to provide for some elevated convection. At this time though it
appears best chance for activity would remain north and east of
forecast area so have trimmed PoPs a bit to into the slight chance
category.
MJM
Medium Range (Sunday through Wednesday)...
Later half of the forecast arrives Sunday with conditions across the
Central Plains warming back up after a few days of below to near
normal temperatures. The pattern across the nation Sunday will begin
rather benignly as it will still be relatively flat, though that
will quickly change as a trough shifts onshore across the Pacific
Coast, with a corresponding amplification of a ridge across the
Plains States. This amplification will bring above normal
temperatures back to the region, which should then prevail through
at least the first half of the work week.
Some focus will be needed for POPs late in the weekend and into the
beginning of the work week. Verity of mid-range models are
advertising a shortwave crossing the ridge axis Sunday, which
generates precipitation across our neck-of-the-woods Sunday and
Sunday night, with some models lingering precipitation into the day
Monday. Confidence on the specifics of the shortwave (like timing
and location) are fairly low, but given the nocturnal environment
that the expanding ridge will bring to the Plains, thoughts are this
shortwave my spawn a MCS Sunday night. Have limited chance POPs to
the overnight hours of Sunday with this expectation. Otherwise,
models also have a smattering of slight chance POPs in the coming
work week, but the output seems to suggest that they are having
issues with the generally warm and moist environment present under
the ridge. So, have trimmed much of the slight chance POPs from the
days after Monday.
Cutter
&&
.AVIATION...
For the 06Z TAFs...VFR showers continue to effect the Kansas City
terminals early this morning, with still another wave of showers
poised to spread across the Kansas-Missouri border again early this
morning. Next round of showers will have some lower ceilings
associated, but have limited the low CIGS to 2500 ft owing to current
upstream trends. What ceilings do move in this morning should scatter
out by the mid-morning hours, with boundary layer mixing then
bringing the days gusty winds.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
354 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.LONG TERM...
ISSUED AT 348 AM CDT THU MAY 31 2012
(FRIDAY THROUGH WEDNESDAY)
IT APPEARS THAT THE PRECIPITATION WILL MOVE E OF OUR FORECAST AREA
BY FRI WITH THE UPPER LOW MOVING INTO NERN IL BY 12Z FRI AND THE SFC
LOW IN NWRN OH AND A TRAILING COLD FRONT EXTENDING S-SW THROUGH KY
AND TN. MAY STILL HAVE SOME CLOUD COVER MAINLY ACROSS THE IL SIDE
OF THE FORECAST AREA. TEMPERATURES ON FRI AND FRI NGT WILL BE BELOW
NORMAL WITH 850 MB TEMPERATURES OF ONLY 4-6 DEGREES C AT 18Z FRI.
TEMPERATURES WILL BEGIN TO MODERATE ON SAT AS THE SFC WINDS BACK
AROUND TO A W-SWLY DIRECTION AS THE SFC RIDGE SHIFTS SE OF OUR
AREA. THE MODELS DEPICT SOME WEAK NW FLOW SHORTWAVES MOVING SEWD
THROUGH THE REGION BUT IT LOOKS LIKE THE PRECIPITATION ASSOCIATED
WITH THESE FEATURES WILL REMAIN N AND E OF OUR AREA ON SAT.
TEMPERATURES WILL CONTINUE TO WARM ON SUN TO ABOVE NORMAL VALUES
AS AN UPPER LEVEL RIDGE TRIES TO BUILD OVER THE PLAINS WITH RISING
HEIGHTS OVER OUR AREA AHEAD OF IT. THE NEXT CHANCE OF PRECIPITATION
WILL OCCUR SUN NGT AND MON AS A NW FLOW SHORTWAVE DROPS SEWD
THROUGH OUR AREA WITH FAIRLY STRONG LOW-MID LEVEL WAA AHEAD OF
IT. PREFER THE ECMWF MODEL SOLUTION AS THE GFS MODEL APPEARS TO
INTENSIFY THE SHORTWAVES TOO MUCH DUE TO FEEDBACK PROBLEMS. THIS
PRECIPITATION SHOULD SHIFT SE OF OUR AREA BY MON NGT WITH THE
UPPER LEVEL RIDGE MOVING OVER MO TUE AND WED LEADING TO MUCH ABOVE
NORMAL TEMPERATURES.
GKS
&&
.AVIATION...
ISSUED AT 1215 AM CDT THU MAY 31 2012
OBSERVED TRENDS ON RADAR AS WELL AS THE LATEST MODEL GUIDANCE NOW
STRONGLY SUGGEST THAT THE TWO MAIN GENERATORS OF RAIN WILL LARGELY
DO THE SPLITS AROUND THE FA. THE FIRST UPPER LEVEL DISTURBANCE
DRIVING THE MCS OVER SERN KS AND FAR SWRN MO WILL EDGE THE FA IN
THE SW AND CLIP KCOU LATE TONIGHT BUT SHOULD ENTIRELY MISS THE STL
METRO TAFS. PCPN ASSOCIATED WITH THE SECOND MORE NLY UPPER LEVEL
SYSTEM IS FILLING IN A BIT MORE OVER IA AND ERN NEBRASKA AND IS
EXPECTED TO MAINLY EDGE THE NRN AND ERN FA LATE TONIGHT AND
THURSDAY. SOME DEGREE OF FILLING IN IS EXPECTED FOR AREAS FURTHER
S INTO STL METRO MAINLY DURING THURSDAY MORNING AND MIDDAY BEFORE
IT ALL HEADS E. SFC LO PRES WILL OOZE THRU THE FA THURSDAY MORNING
WHEN THIS PCPN SHOULD TRY TO FILL IN...WITH A TRAILING CDFNT IS
THEN EXPECTED TO SWEEP THRU AND END MUCH OF THE PCPN CHCS AT THAT
POINT. SOME PATCHY LIGHT PCPN IS STILL POSSIBLE HEADING INTO THE
EVENING.
SPECIFICS FOR KSTL...VFR CONDITIONS TO PREVAIL AT THIS POINT UNTIL
PROBABLY THURSDAY AFTERNOON WHEN CD FROPA IS EXPECTED TO BRING IN
SOME WRAPAROUND LO CLOUDS THAT WILL LAST THRU MUCH OF THURSDAY
NIGHT. PCPN CHCS LOOK PRETTY MINIMAL WITH FIRST WAVE NOW
PROCEEDING THRU SERN KS AND SWRN MO AND IFFY WITH THE SECOND WAVE.
MAY SEE SOME FILLING IN THURSDAY MORNING AND MIDDAY WHEN SECOND
WAVE PASSES MAINLY TO THE N BUT FROPA SHOULD LARGELY END PCPN
CHCS...ALTHOUGH SOME PATCHY LIGHT PCPN STILL POSSIBLE. HAVE HELD
OFF ON IFR LATE THURSDAY UNTIL WE SEE BETTER EVIDENCE OF
WIDESPREAD LO CLOUD DEVELOPMENT.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
301 AM CDT THU MAY 31 2012
.SHORT TERM...
ISSUED AT 255 AM CDT THU MAY 31 2012
(TODAY AND TONIGHT)
MAIN FORECAST CONCERN IS AREAL EXTENT OF CATEGORICAL POPS AND THE
POTENTIAL FOR A FEW SEVERE THUNDERSTORMS OVER THE SOUTHERN PART OF
THE CWA. PRECIPITATION FROM THIS SYSTEM HAS NOW CONCENTRATED IN TWO
SEPARATE MASSES...ONE WHICH IS OVER IOWA AND A MCS OVER SOUTHWEST
MISSOURI/NORTHEAST OKLAHOMA WHICH NOW MOVING EASTWARD. THE FORWARD
PROPAGATING MOTION VECTORS ON THE RAP SUGGEST THAT THIS COMPLEX WILL
CONTINUE TO MOVE EASTWARD AND SHOULD REACH THE SOUTHERN PART OF THE
CWA INCLUDING CRAWFORD AND REYNOLD COUNTIES BY 12Z. THEREAFTER...
SURFACE LOW CURRENTLY OVER NORTHWEST ARKANSAS WILL MOVE INTO EAST
CENTRAL MO BY MID MORNING WHICH IS CONSISTENT WITH THE GFS/LOCAL
WRF. LARGE SCALE ASCENT WILL INCREASE OVER THE CWA THIS MORNING IN
RESPONSE TO GREAT PLAINS TROUGH WHICH CONTINUES TO DEEPEN AND SHOULD
CAUSE AN INCREASE IN AREAL COVERAGE OF SHOWERS AND THUNDERSTORMS
TO THE NORTH OF THE ONGOING MCS. ATMOSPHERE WILL BECOME INCREASING
UNSTABLE OVER THE SOUTHERN CWA WITH MUCAPES AROUND 1000 J/KG AND
DEEP LAYER AROUND 40 KTS. THIS SUGGESTS THE POTENTIAL FOR A FEW
SEVERE THUNDERSTORMS PRODUCING LARGE HAIL AND DAMAGING WINDS LATE
THIS MORNING AND EARLY AFTERNOON BEFORE THE SHORTWAVE TROUGH AND
SURFACE LOW MOVE EAST OF THE AREA BY 21Z. SO WILL MAINTAIN
CATEGORICAL THREAT FOR SHOWERS AND THUNDERSTORMS OVER THE ENTIRE
CWA FOR LATER THIS MORNING INTO THE THE AFTERNOON BEFORE POPS
RAPIDLY DECREASE TO JUST CHANCES OVER JUST SOUTH CENTRAL ILLINOIS
DURING THE EARLY EVENING HOURS. EXPECT DRY WEATHER AND DECREASING
CLOUDS AFTER MIDNIGHT AS STRONG SUBSIDENCE SETS IN BEHIND THE
UPPER TROUGH.
TEMPERATURES WILL LIKELY REMAIN STEADY AND THEN FALL THIS AFTERNOON
OVER NORTHEAST MISSOURI/WEST CENTRAL ILLINOIS TO THE NORTH OF THE
SURFACE TRACK. MY HIGHS ARE CLOSER TO THE COOLER NAM MOS
TEMPERATURES FOR TODAY. MOS LOWS TONIGHT ARE IN GOOD AGREEMENT AND
LINE UP WELL WITH A BLEND OF THE 2M TEMPS FROM THE MODELS.
BRITT
&&
.AVIATION...
ISSUED AT 1215 AM CDT THU MAY 31 2012
OBSERVED TRENDS ON RADAR AS WELL AS THE LATEST MODEL GUIDANCE NOW
STRONGLY SUGGEST THAT THE TWO MAIN GENERATORS OF RAIN WILL LARGELY
DO THE SPLITS AROUND THE FA. THE FIRST UPPER LEVEL DISTURBANCE
DRIVING THE MCS OVER SERN KS AND FAR SWRN MO WILL EDGE THE FA IN
THE SW AND CLIP KCOU LATE TONIGHT BUT SHOULD ENTIRELY MISS THE STL
METRO TAFS. PCPN ASSOCIATED WITH THE SECOND MORE NLY UPPER LEVEL
SYSTEM IS FILLING IN A BIT MORE OVER IA AND ERN NEBRASKA AND IS
EXPECTED TO MAINLY EDGE THE NRN AND ERN FA LATE TONIGHT AND
THURSDAY. SOME DEGREE OF FILLING IN IS EXPECTED FOR AREAS FURTHER
S INTO STL METRO MAINLY DURING THURSDAY MORNING AND MIDDAY BEFORE
IT ALL HEADS E. SFC LO PRES WILL OOZE THRU THE FA THURSDAY MORNING
WHEN THIS PCPN SHOULD TRY TO FILL IN...WITH A TRAILING CDFNT IS
THEN EXPECTED TO SWEEP THRU AND END MUCH OF THE PCPN CHCS AT THAT
POINT. SOME PATCHY LIGHT PCPN IS STILL POSSIBLE HEADING INTO THE
EVENING.
SPECIFICS FOR KSTL...VFR CONDITIONS TO PREVAIL AT THIS POINT UNTIL
PROBABLY THURSDAY AFTERNOON WHEN CD FROPA IS EXPECTED TO BRING IN
SOME WRAPAROUND LO CLOUDS THAT WILL LAST THRU MUCH OF THURSDAY
NIGHT. PCPN CHCS LOOK PRETTY MINIMAL WITH FIRST WAVE NOW
PROCEEDING THRU SERN KS AND SWRN MO AND IFFY WITH THE SECOND WAVE.
MAY SEE SOME FILLING IN THURSDAY MORNING AND MIDDAY WHEN SECOND
WAVE PASSES MAINLY TO THE N BUT FROPA SHOULD LARGELY END PCPN
CHCS...ALTHOUGH SOME PATCHY LIGHT PCPN STILL POSSIBLE. HAVE HELD
OFF ON IFR LATE THURSDAY UNTIL WE SEE BETTER EVIDENCE OF
WIDESPREAD LO CLOUD DEVELOPMENT.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1021 PM CDT FRI JUN 1 2012
.UPDATE...JUST COMPLETED AN UPDATE ADDRESSING ONLY THE OVERNIGHT
PERIOD THROUGH 12Z. PRIMARY CHANGE WAS TO LINGER A TOKEN 20
PERCENT CHANCE OF SHOWERS THROUGH 06Z ACROSS MAINLY THE EASTERN
1/2 OF THE CWA...AS RADAR TRENDS CONFIRM THAT POTENTIALLY SPOTTY
MEASURABLE RAIN WILL NOT BE OUT OF THE CWA BY 03Z AS EARLIER
FORECAST INDICATED. PULLED THUNDER WORDING FOR THE NIGHT...AS NO
LIGHTNING STRIKES HAVE BEEN DETECTED FOR A FEW HOURS NOW AND
REMAINING MUCAPE IS ALMOST NIL PER RUC-BASED MESOANALYSIS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS
FAIRLY SHARP NORTHWEST FLOW ALOFT...WITH THE LINGERING SHOWERS
CONCENTRATED WITHIN A CORRIDOR OF SUBTLE MID LEVEL SHORTWAVE
ENERGY AND AN 80-90KT UPPER LEVEL JET STREAK. AS THE NIGHT WEARS
ON...THIS MODEST UPPER SUPPORT SHOULD SLIDE OFF TO THE SOUTH AND
EAST OF THE CWA...AND THUS HAVE NO PRECIPITATION MENTION POST-06Z.
THAT BEING SAID...THE LATEST HRRR REFLECTIVITY PROG TRIES TO BRING
A NARROW BAND OF SPRINKLES/LIGHT SHOWERS ACROSS THE FAR SOUTHWEST
CWA BETWEEN 09Z-12Z...WHICH SEEMS TO BE TIED TO ANOTHER SUBTLE
RIBBON OF FRONTOGENESIS/THETA-E ADVECTION EVIDENT AROUND 700MB.
WILL OMIT THIS FROM THE FORECAST FOR NOW...BUT WOULD NOT SURPRISED
TO SEE IT FORM...AS THE LAST 18 HOURS HAVE AGAIN PROVEN THAT GETTING
CONSIDERABLE LEAD TIME ON LOW-IMPACT RAINFALL EVENTS IN NORTHWEST
FLOW IS NOTORIOUSLY CHALLENGING. TEMPERATURE WISE...MADE NO CHANGE
WHATSOEVER TO OVERNIGHT LOWS...STILL AIMING FOR UPPER 40S-LOW 50S.
PER LATEST HOURLY GFS LAMP GUIDANCE...THERE ARE HINTS THAT
LINGERING MID LEVEL CLOUDS COULD HOLD THINGS UP THINGS A FEW
DEGREES WARMER THAN ADVERTISED...BUT AFTER DIPPING BELOW FORECAST
LOWS THE PAST FEW MORNINGS AM NOT GOING TO BET ON IT. ALSO THERE
ARE SOME HINTS THAT LIGHT FOG COULD TRY FORMING LATE TONIGHT OVER
THE MOIST GROUND IN AREAS THAT SAW RAINFALL DURING THE PAST 18
HOURS...BUT CONFIDENCE IS LOW IN DEVELOPMENT GIVEN CONSIDERABLE
MID LEVEL CLOUDS THAT WILL ALSO OMIT THIS MENTION FROM GRIDS.
&&
.PREV DISCUSSION... /ISSUED 609 PM CDT FRI JUN 1 2012/
AVIATION...00Z KGRI TAF. VFR CEILING AND VISIBILITY ARE FORECAST
THROUGH THE NEXT 24 HOURS. STARTING OFF FOR THE FIRST FEW HOURS
THIS EVENING...WILL INTRODUCE A VICINITY SHOWER MENTION TO ACCOUNT
FOR SOME SHOWER/WEAK THUNDERSTORM ACTIVITY SLIDING DOWN FROM THE
NORTH. IF CONFIDENCE INCREASES THAT THESE SHOWERS WILL HOLD
TOGETHER LONG ENOUGH TO DIRECTLY IMPACT KGRI WILL AMEND WITH A
SHORT-FUSE TEMPO GROUP. OTHERWISE...PRECIPITATION CHANCES ARE
ESSENTIALLY NILL BEYOND THIS EVENING...WITH ONLY FEW TO SCATTERED
MID-HIGH LEVEL CLOUDS IN PLACE FOR SATURDAY. ALTHOUGH SURFACE
BREEZES ARE LIKELY TO AVERAGE UNDER 10KT THROUGH MOST IF NOT ALL
OF THE PERIOD...DIRECTION WILL BE A BIT VARIABLE. THIS
EVENING/OVERNIGHT...A MIX OF SOUTHERLY AND WESTERLY BREEZES WILL
PREVAIL. THEN DURING THE DAY SATURDAY...OPTED TO SIMPLY USE VARIABLE
6KT WORDING...AS A PASSING SURFACE HIGH PRESSURE AXIS WILL
GRADUALLY TRANSITION BREEZES FROM WESTERLY TO EASTERLY TO
SOUTHEASTERLY. ADDING ADDITIONAL WIND DETAIL BEYOND THE FIRST 12
HOURS IS TRICKY AT THIS TIME RANGE GIVEN SUCH LOW SPEEDS.
PREV DISCUSSION... /ISSUED 353 PM CDT FRI JUN 1 2012/
SHORT TERM...THROUGH SATURDAY. MORNING UPPER AIR ANALYSIS
INDICATES UPPER LEVEL TROUGHING OVER THE CENTRAL CONUS WITH
RIDGING OVER THE WEST AND EAST. MID AND UPPER LEVEL JET ENERGY
REMAINS POSITIONED FROM THE PACIFIC NORTHWEST...SOUTHEASTWARD INTO
THE CENTRAL PLAINS AND THEN NORTHEASTWARD INTO THE NORTHEASTERN
CONUS. MID-AFTERNOON WATER VAPOR IMAGERY SHOWS INCREASING MID
LEVEL MOISTURE FLOWING IN FROM THE PACIFIC INTO THE NORTHWESTERN
CONUS...AND SOUTHEASTWARD INTO THE CENTRAL PLAINS. A MID LEVEL LOW
IS NOTED OVER THE GREAT LAKES REGION...AND A MID LEVEL SHORT WAVE
OVER THE THE DAKOTAS. AT THE SURFACE AN AREA OF HIGH PRESSURE IS
NOTED NEAR KEMP...AND A TROUGH EXISTS FROM WESTERN NEBRASKA ON
SOUTH ALONG THE COLORADO/KANSAS BORDER. AS A RESULT...LOW LEVEL
FLOW GENERALLY REMAINS FROM THE SOUTH ACROSS OUR CWA.
GUIDANCE SUGGESTS THE MID LEVEL SHORT WAVE OVER THE DAKOTAS WILL
PUSH SOUTHEAST LATE THIS AFTERNOON THROUGH TONIGHT...THUS PROMOTING
A WEAK SURFACE LOW OVER THE UPPER MISSISSIPPI VALLEY WHICH SHOULD
HELP PULL THE WESTERN NEBRASKA SURFACE TROUGH EAST/SOUTHEAST ACROSS
OUR AREA. THE BULK OF THE THERMAL ADVECTION AND DPVA IN ASSOCIATION
WITH THE MID LEVEL SHORT WAVE SHOULD REMAIN EAST/NORTHEAST OF OUR
AREA...BUT JUST ENOUGH MID LEVEL OMEGA...ALONG WITH SOME LOW LEVEL
CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH...MAY BE ENOUGH TO
PROMOTE SOME PRECIPITATION ACROSS OUR NORTH AND EAST LATE THIS
AFTERNOON THROUGH THIS EVENING. RAIN FROM EARLIER TODAY HAS
ENCASED MUCH OF OUR CWA UNDER A MESO-HIGH AND WITH LOW LEVEL
MOISTURE QUITE LOW...INSTABILITY IS HARDLY ANYTHING TO GET EXCITED
ABOUT. THAT BEING SAID...VISIBILITY SATELLITE IMAGERY DOES
INDICATE CLOUDS BEGINNING TO BREAK ACROSS OUR NORTH/NORTHWEST AND
IF THIS TREND CONTINUES...IT IS POSSIBLE THAT WHAT LITTLE DIABATIC
HEATING WE RECEIVE THIS AFTERNOON...ALONG WITH SOMEWHAT INCREASING
MID LEVEL LAPSE RATES IN THE VICINITY OF THE MID LEVEL TROUGH AXIS
PASSING JUST TO OUR NORTHEAST...COULD PERHAPS PROMOTE ~100J/KG
DEEP LAYER MUCAPE. GIVEN ALL THIS...WILL GO AHEAD AND INCLUDE A
SLIGHT CHANCE POP ACROSS OUR NORTH AND EAST 21Z-03Z...WITH THUNDER
MENTION ALSO INCLUDED. SUBSIDENCE WILL SETTLE IN ACROSS THE AREA
BY 03Z TONIGHT AS THE MID LEVEL TROUGH AXIS PUSHES WELL
EAST/SOUTHEAST OF OUR AREA...AND WITH AN OVERALL LACK IN KINEMATIC
FORCING DRY CONDITIONS SHOULD THEN PRESENT THEMSELVES TO OUR AREA
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST PERIOD.
BELOW-NORMAL LOWS ARE STILL EXPECTED TONIGHT AS SKIES CLEAR OUT AND
RELATIVELY HIGH PRESSURE REMAINS SITUATED OVER THE AREA. CLEARING
SKIES...DRY CONDITIONS AND A DOWN-SLOPING WESTERLY LOW LEVEL WIND
FIELD WILL THEN HELP PROMOTE A MUCH WARMER DAY ON SATURDAY...WITH
HIGHS IN THE 80S FORECAST FOR THE MOST PART.
LONG TERM...SATURDAY NIGHT THROUGH SUNDAY. BIGGEST CHALLENGE WILL
RECURRING CHANCES OF SHOWERS AND THUNDERSTORMS.
EXTENDED MODELS ARE IN PRETTY GOOD AGREEMENT...BUT THERE ARE SOME
DIFFERENCES IN THE LARGE SCALE SOLUTIONS.
FOR SATURDAY NIGHT...WE BEGIN WITH AN AMPLIFYING UPPER LEVEL PATTERN
WITH A RIDGE DEVELOPING OVER THE ROCKY MOUNTAINS/CENTRAL
PLAINS...FLANKED BY AN ALREADY DEEPLY AMPLIFIED MEAN TROUGH TO THE
EAST AND DEVELOPING TROUGH OVER THE NORTHERN ATLANTIC...ENTERING THE
PACIFIC NORTHWEST. BY LATE SATURDAY NIGHT A MODEST LOW-LEVEL JET
DEVELOPS OVER THE HIGH PLAINS AND NUDGES EAST...WITH THE THETA-E
AXIS MAKING ITS WAY INTO THE WESTERN CWA...HELPING TO GIVE US A BIT
OF A CHANCE OF SHOWERS AND THUNDERSTORMS. BULK SHEAR WILL BE
WEAK...AND INSTABILITY IS NOT IMPRESSIVE. THIS WILL NOT BE A
SCENARIO FOR WIDESPREAD STRONG OR SEVERE THUNDERSTORMS...MORE LIKE
AN ISOLATED STRONG STORM FOR THIS TIME PERIOD.
BY SUNDAY...THE INSTABILITY AXIS ASSOCIATED WITH A WEAK SURFACE
FRONT/TROUGH SHOULD BE SOMEWHERE OVER THE CWA...WHICH WILL HELP
SPARK SOME THUNDERSTORMS MAINLY IN THE AFTERNOON AND EVENING.
INSTABILITY WILL BE GREATER THAN SATURDAY NIGHT THANKS TO THE WEAK
BOUNDARY...SO WILL BE A BETTER SHOT AT A FEW SEVERE
THUNDERSTORMS...ALTHOUGH SHEAR WILL REMAIN WEAK AND INSTABILITY WILL
BE MODERATE.
THE SCENARIO OF MODERATE INSTABILITY AND LOW SHEAR WILL HOLD THROUGH
WEDNESDAY...ALTHOUGH IT APPEARS THAT CONVECTION SHOULD REMAIN IN THE
HIGH PLAINS FOR MONDAY AND TUESDAY. WILL KEEP CHANCES OF STRONG TO
SEVERE SHOWERS AND THUNDERSTORMS AROUND FOR TUESDAY NIGHT INTO
FRIDAY...BUT NO WIDESPREAD OUTBREAK IS ANTICIPATED AS OF NOW AS
SEVERE POTENTIAL LOOKS BEST IN THE HIGHER PLAINS. THE HEAT WILL ALSO
INCREASE QUITE A BIT UNDER THE RIDGE WITH HIGHS IN THE MID 80S TO
LOWER 90S FROM SUNDAY THROUGH WEDNESDAY. SO FOR MONDAY INTO
TUESDAY...KEEPING DRY EXCEPT SOME FAR WESTERN AREAS ON TUESDAY
AFTERNOON.
BY TUESDAY NIGHT...MODELS SHOW THAT THE MORE NEGATIVELY
TILTED UPPER LEVEL TROUGH TO THE WEST COULD INCLUDE A CLOSED LOW.
WHAT MODELS DO WITH THE LOW DIFFER TO SOME DEGREE...BUT I TEND TO
LIKE THE ECMWF/ECMWF ENSEMBLES SOLUTION FOR THE PAST CONSISTENCY. BY
THURSDAY...THE CLOSED LOW SHOULD JOIN WITH THE SEVERELY POSITIVELY
TILTED LONGWAVE TROUGH ON THE EAST FLANK OF THE CENTRAL RIDGE AND
THEN BISECT THE RIDGE ACROSS THE NORTHERN/CENTRAL PLAINS IN AN
WEST-EAST ORIENTATION. THE GFS DOES NOT SHOW THIS...BUT KEEPS THE
RIDGE IN TACT. AT THE SAME TIME...AT THE SURFACE THE ECMWF DEPICTS
AN INVERTED TROUGH STRETCHING INTO THE CWA FROM THE SOUTH. THIS
TROUGHINESS SHOULD GIVE US OUR BEST SHOT AT PRECIPITATION FOR THE
LONG TERM ON WEDNESDAY NIGHT/THURSDAY. THIS WOULD ALSO BE THE TIME
PERIOD THAT WOULD BE MORE FAVORABLE TOWARD POSSIBLE SEVERE WEATHER
AS WE HAVE A MORE FAVORABLE SYNOPTIC ENVIRONMENT AND STRONGER FOCUS
AT THE SURFACE. THIS SCENARIO IS A BIT DICEY TO PREDICT AND
CONFIDENCE IN THE SYNOPTIC SCALE EVOLUTION IS NOT THE
GREATEST...WITH SMALLER DETAILS BEING QUITE UNCERTAIN. A COOL DOWN
IS IN ORDER FOR THURSDAY INTO FRIDAY AS THE RIDGE GETS PINCHED WITH
HIGHS IN THE 70S BY FRIDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM...BRYANT
LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1238 AM CDT THU MAY 31 2012
.AVIATION...06Z KGRI TAF...IFR CIGS WILL CONTINUE FOR THE NEXT
HOUR OR TWO AT KGRI AS CIGS ALONG LEADING EDGE OF STRATUS RUNNING
BETWEEN 7 AND 9 HUNDRED FEET. HOWEVER...EXPECT THESE IFR CIGS TO
BE BRIEF BASED ON UPSTREAM OBSERVATIONS...AND BROUGHT CIGS UP TO
MVFR LEVELS BY 08Z. THEREAFTER...EXPECT LOW LEVEL STRATUS TO HOVER
AT THE TERMINAL THROUGH THE AFTERNOON HOURS THURSDAY...SLOWLY
LIFTING AND EVENTUALLY CLEARING BY AROUND 02Z FRIDAY. WINDS WILL
GENERALLY REMAIN NORTHERLY THROUGH THE PERIOD BETWEEN
12-18KTS...AS A SURFACE HIGH ACROSS THE NORTHERN PLAINS CONTINUES
ITS ADVANCE SOUTHWARD. THIS HIGH WILL BECOME CENTERED ACROSS
NEBRASKA BY EARLY EVENING...AND THEREFORE EXPECT A RETURN TO LIGHT
WINDS AROUND SUNSET.
&&
.PREV DISCUSSION... /ISSUED 938 PM CDT WED MAY 30 2012/
UPDATE...AFTER A MORE-ACTIVE-THAN-EXPECTED DAY THAT FEATURED
ROUGHLY 6 HOURS OF SEVERE THUNDERSTORMS MAINLY ACROSS THE SOUTHERN
1/2 OF THE CWA...THINGS HAVE QUIETED DOWN CONSIDERABLY OVER THE
PAST FEW HOURS...WITH WHAT SHOULD BE THE LAST FEW WEAK STORMS OF
THE EVENING GRADUALLY EXITING A HANDFUL OF FAR SOUTHERN/SOUTHEASTERN
COUNTIES WITHIN THE NEXT 1-2 HOURS. 02Z OBJECTIVE SURFACE ANALYSIS
DEPICTS THE PRIMARY SYNOPTIC COLD FRONT PUSHING SOUTH OUT OF FAR
SOUTHERN NEB ZONES INTO KS...WITH STEADY BUT NOT OVERLY STRONG NORTH
BREEZES PUSHING IN BEHIND THE FRONT...DRIVEN BY A 1020MB HIGH
CENTERED OVER SOUTHERN ND/NORTHERN SD. ALTHOUGH OBJECTIVE
MESOSCALE ANALYSIS INDICATED THAT PARTS OF NORTH CENTRAL KS ZONES
MAY STILL BE HOLDING ON TO MUCAPE IN EXCESS OF 500 J/KG...THUNDER
POTENTIAL IS DEFINITELY ON A FAST DECLINE AS THE LOW LEVEL COLD
FRONT CONTINUES TO PUSH SOUTHWARD. ALOFT...WATER VAPOR IMAGERY
SHOWS THE PRIMARY WEST-NORTHWEST FLOW 500MB VORT MAX CENTERED NEAR
THE IA/NE/SD/MN BORDER AREA...WITH THE BEST LARGE SCALE FORCING
STEADILY DEPARTING EAST AS THE NIGHT PROGRESSES. ALTHOUGH SOME
LIGHT SHOWER POTENTIAL CANNOT BE RULED OUT AFTER MIDNIGHT EVEN
AFTER THUNDER EXITS...DECIDED THAT SUPPORT FOR MEASURABLE PRECIP
WAS LOW ENOUGH POST-06Z TO SIMPLY GO WITH A SLIGHT CHANCE OF
SPRINKLES...AND EVEN THIS MAY BE OVERKILL PER THE LATEST HRRR RUNS.
MAY TWEAK OVERNIGHT LOWS DOWNWARD VERY SLIGHTLY ON ONE MORE
FORECAST UPDATE WITHIN THE NEXT HOUR...WITH MUCH OF THE NORTHERN
CWA LIKELY HEADED FOR THE MID 40S...WITH UPPER 40S/NEAR 50
PREVAILING SOUTH. CLOUD TRENDS OVERNIGHT ARE SOMEWHAT
UNCERTAIN...AND EXPECT SOME VARIABILITY AS MID/HIGH CLOUDS RETREAT
SOMEWHAT FROM THE SOUTH AND LOWER STRATUS WORKS IN FROM THE NORTH.
PREV DISCUSSION... /ISSUED 306 PM CDT WED MAY 30 2012/
SHORT TERM...THROUGH 00Z FRIDAY. MORNING UPPER AIR ANALYSIS
INDICATES QUASI-ZONAL TO NORTHWESTERLY MID AND UPPER LEVEL FLOW
ACROSS CENTRAL PORTIONS OF THE CONUS...WITH SUBTLE RIDGING ACROSS
THE WESTERN AND EASTERN CONUS. MID AND UPPER LEVEL JET ENERGY IS
POSITIONED FROM THE NORTHWESTERN CONUS...ACROSS CENTRAL PORTIONS
OF THE CONUS AND ON INTO THE EASTERN CONUS. EARLY AFTERNOON WATER
VAPOR IMAGERY SHOWS INCREASED VALUES OF MID LEVEL MOISTURE FLOWING
IN FROM THE PACIFIC...PUSHING ACROSS THE NORTHWESTERN CONUS AND
INTO THE CENTRAL PLAINS. A MID LEVEL SHORT WAVE IS ALSO NOTED OVER
THE NORTHERN PLAINS...MOVING EAST/SOUTHEAST. AT THE SURFACE A
TROUGH OF LOW PRESSURE IS NOTED EXTENDING ACROSS WESTERN NEBRASKA.
IN ADDITION...AN AREA OF HIGH PRESSURE IS LOCATED OVER THE UPPER
MISSISSIPPI VALLEY...WITH LOW LEVEL RETURN FLOW ON THE BACK SIDE
OF THE SURFACE RIDGE INFILTRATING PORTIONS OF THE CENTRAL PLAINS.
THAT BEING SAID...CONVECTIVELY INDUCED OUTFLOW AT THE SURFACE
IS PROMOTING A BIT MORE CHAOTIC LOW LEVEL WIND FIELD ACROSS OUR
CWA...THAN THAT OF THE TRUE SOUTHEASTERLY WINDS WHICH ARE TRYING
TO DEVELOP. THIS MESO-HIGH IS PROMOTING A DIFFERENTIAL HEATING
BOUNDARY NOW EVIDENT ACROSS WESTERN PORTIONS OF OUR CWA. KUEX
INDICATES CONVECTION PERSISTING ACROSS MUCH OF SOUTH CENTRAL
NEBRASKA AS OF MID AFTERNOON.
LOW LEVEL RETURN FLOW IS HELPING PROMOTE LOW LEVEL THERMAL
ADVECTION AND RESULTANT ISENTROPIC UPGLIDE AND SATURATION OVER OUR
CWA...PRIMARILY ALONG THE 300-310K SURFACES. LAPS PROXIMITY
SOUNDINGS FROM ACROSS OUR WESTERN CWA SUGGEST AIR
PARCELS...ASCENDING FROM AROUND 700MB...ARE CONTENDING WITH LESS
THAN 30J/KG CIN AND WORKING WITH 600-1000J/KG CAPE. IN ADDITION...MID
AND UPPER LEVEL JET ENERGY IS HELPING PROMOTE DEEP LAYER BULK
SHEAR VALUES OF 30-40KTS. EVEN THOUGH THE INSTABILITY IS NOT
OVERLY IMPRESSIVE...THE COOL LOW TO MID LEVEL AIRMASS AND THE DEEP
LAYER SHEAR ARE MORE THAN COMPENSATING...WITH SEVERAL REPORTS OF
HAIL ALREADY REPORTED ACROSS THE AREA TODAY. BROAD-SCALE ASCENT
SHOULD PERSIST THROUGH THE REST OF THIS AFTERNOON AND INTO
TONIGHT...WITH DEEP LAYER SHEAR AND INSTABILITY ALSO LIKELY
PERSISTING. IN ADDITION...VISIBLE SATELLITE IMAGERY INDICATES LOW
LEVEL CONVERGENCE...ALONG THE DIFFERENTIAL HEATING BOUNDARY ACROSS
WESTERN PORTIONS OF THE CWA...IS HELPING TO PROMOTE WEAK
CONVECTIVE ACTIVITY. FINALLY...KLNX INDICATES ADDITIONAL
CONVECTION FIRING ALONG THE SURFACE TROUGH ACROSS WESTERN
NEBRASKA. THE TROUGH ACROSS WESTERN NEBRASKA...AND THE
DIFFERENTIAL HEATING BOUNDARY OVER WESTERN PORTIONS OF THE
CWA...ARE EXPECTED TO PUSH ACROSS OUR CWA THIS EVENING AND TONIGHT
AS THE MID LEVEL SHORT WAVE...CURRENTLY OVER THE NORTHERN
PLAINS...ALSO PUSHES EAST/SOUTHEAST. AT THIS TIME IT APPEARS THE
BULK OF THE BROAD-SCALE ASCENT AHEAD OF THE NORTHERN PLAINS MID
LEVEL TROUGH AXIS SHOULD REMAIN TO OUR NORTHEAST...BUT ADDITIONAL
CONVECTIVE ACTIVITY WILL BE POSSIBLE OVER OUR AREA THROUGH TONIGHT
AS THE SURFACE TROUGH AND DIFFERENTIAL HEATING
BOUNDARY/STRENGTHENING LOW LEVEL BAROCLINIC ZONE CLEARS THE AREA.
GIVEN ALL THIS...WENT AHEAD AND PRESENTED LIKELY TO DEFINITE POPS
ACROSS THE CWA THROUGH 06Z...WITH POPS TAPERING OFF AFTER 06Z AS
LOW LEVEL FORCING MOVES OFF TO THE EAST/SOUTHEAST. GIVEN THE
AFOREMENTIONED INSTABILITY AND DEEP LAYER SHEAR...WILL ALSO
CONTINUE THE SEVERE WORDING ACROSS THE AREA THROUGH THIS EVENING.
LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY. MAIN FORECAST
CONCERNS WILL BE CHANCES FOR THUNDERSTORMS ON AND OFF DURING THE
PERIOD AND TEMPERATURES.
START OFF THE PERIOD WITH NORTHWEST FLOW THAT BRINGS SEVERAL WEAK
UPPER LEVEL WAVES THROUGH THE REGION THURSDAY NIGHT THROUGH
SATURDAY. THE BEST OF THOSE WAVES SEEMS TO BE DURING THE FRIDAY TO
FRIDAY NIGHT TIME FRAME.
SATURDAY NIGHT THROUGH TUESDAY THERE IS AN UPPER LEVEL RIDGE THAT
MOVES THROUGH THE PLAINS. TEMPERATURES WARM UP...BUT THERE REMAINS
SOME WEAK UPPER LEVEL WAVES THAT MOVE THROUGH THE AREA AND BRING
SOME SPORADIC CHANCES FOR THUNDERSTORMS TO THE FORECAST AREA.
TUESDAY NIGHT INTO WEDNESDAY AN UPPER LEVEL LOW BREAKS DOWN THE
RIDGE AND A SURFACE LOW IN THE SOUTHERN PLAINS HAS AN INVERTED
TROUGH TO THE NORTH ACROSS THE AREA. WITH THIS THERE IS A CHANCE FOR
SOME THUNDERSTORMS. TEMPERATURES WILL COOL A LITTLE BIT AGAIN AFTER
THE RIDGE BREAKS DOWN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ROSSI
UPDATE...PFANNKUCH
SHORT TERM...BRYANT
LONG TERM...JCB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1006 PM EDT FRI JUN 1 2012
.SYNOPSIS...
DRIER AND SLIGHTLY COOLER AIR WILL OVERSPREAD THE REGION SATURDAY
AND SUNDAY BEHIND A COLD FRONT. ANOTHER COLD FRONT WILL CROSS THE
AREA TUESDAY MORNING. AN UPPER TROUGH LINGERING ALONG THE EASTERN
SEABOARD COULD BRING ISOLATED TO SCATTERED THUNDERSTORMS MUCH OF
NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1000 PM FRIDAY...PREFRONTAL BAND OF CONVECTION CROSSING THE
PEE DEE REGION HAS BEGUN TO WEAKEN. HOWEVER A CORRIDOR OF MARGINAL
SURFACE-BASED INSTABILITY REMAINS IN PLACE AHEAD OF THIS LINE FROM
ROUGHLY BENNETTESVILLE TO WILMINGTON. ALTHOUGH THE SEVERE THREAT
IS DIMINISHING...THIS CONVECTION MAY HOLD TOGETHER FOR A FEW MORE
HOURS AS IT MAKES ITS WAY TO THE COAST. BUT SINCE WE EXPECT THE
WEAKENING TREND TO CONTINUE...THE SEVERE THUNDERSTORM WATCH WILL
EXPIRE ON SCHEDULE AT 10 PM.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 330 PM FRIDAY...TREMENDOUSLY DIFFERENT FEEL TO THE WEATHER
THIS WEEKEND AS AN UNSEASONABLY ROBUST COLD FRONT MOVES OFFSHORE
FOLLOWED BY COOL AIR ADVECTION AND DRIER AIR INTO THE REGION.
THIS WILL RESULT IN A PCPN-FREE WEEKEND AND AN ALMOST "CRISP" FEEL
TO THE AIR SUNDAY MORNING WITH LOWS IN THE MID AND UPPER 50S AND
AROUND 60 AT THE COAST. MAX TEMPS TO RUN BELOW NORMAL WITH SUNDAY
MILDEST.
TIDAL CALCULATIONS INDICATE WE MAY NEED A COASTAL FLOOD ADVISORY
MAINLY FOR NUISANCE FLOODING DURING HIGH TIDES OVER THE WEEKEND.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 330 PM FRIDAY...PERSISTENT UPPER TROUGHINESS REMAINS IN PLACE
OVER THE NORTHEASTERN U.S. AND MIDATLANTIC THROUGH THE PERIOD. THIS
WILL ALLOW PIECES OF SHORTWAVE ENERGY TO MOVE THROUGH AT JUST ABOUT
ANY TIME BUT THESE FEATURES WILL BE TOO MOISTURE-DEPRIVED TO YIELD
ANY APPRECIABLE PRECIP CHANCES. THE STRONGEST OF THESE UPPER WAVES
MOVES THROUGH LATE TUESDAY OR TUESDAY NIGHT (OR MONDAY NIGHT
ACCORDING TO ECMWF) AND MAY BE STRONG ENOUGH TO HAVE A SURFACE
REFLECTION ALONG THE WEAK FRONTAL BOUNDARY IT DRIVES THROUGH THE
CAROLINAS. THIS EVENT WILL BRING THE BEST CHANCE FOR RAIN DURING THE
LONG TERM BUT CHANCES WILL NOT BE VERY HIGH AND THE CONTINUED
RELATIVE DRYNESS WILL MINIMIZE QPF WHERE PRECIP DOES MANAGE TO
OCCUR. TEMPERATURE DEVIATIONS FROM CLIMO WILL TEND TO BE SMALL...A
FEW DEGREES SHY BY DAY FROM WEAK CAA AND LOW HEIGHTS...A FEW DEGREES
ABOVE AT NIGHT DUE TO CLOUD COVER.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 23Z...FIRST BAND OF CONVECTION IS NOW EAST OF THE INLAND
TERMINALS...AND WILL LIKELY DISSIPATE BEFORE REACHING THE COAST.
BASED ON THE HRRR MODEL...ANOTHER ROUND OF CONVECTION IS EXPECTED TO
MOVE INTO THE WESTERN TERMINALS FROM 00-03Z. THIS CONVECTION HAS
SOME DYNAMICS TO SUPPORT IT...BUT THE LOSS OF SOLAR INSOLATION
SHOULD KEEP THE INTENSITY DOWN...WITH MVFR CONDITIONS EXPECTED WORST
CASE. OVERNIGHT...COLD FRONT WILL SWEEP THROUGH THE REGION FROM WEST
TO EAST WITH A WIND SHIFT TO THE NORTHWEST AND THE CESSATION OF ANY
PRECIP. SOME LIGHT SHOWERS COULD MAKE IT TO THE COAST...BUT WENT
WITH VCSH. SATURDAY...A NICE AVIATION DAY IN STORE WITH VFR
CONDITIONS AND A LIGHT NORTHWEST FLOW CONTINUING.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
THROUGH SATURDAY. VFR EXPECTED FRIDAY THROUGH THE END OF THE PERIOD.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 PM FRIDAY...LATEST AREA OBSERVATIONS ALONG THE COAST
INDICATE PREFRONTAL WINDS IN THE 20-25 KT RANGE WITH OCCASIONAL
GUSTS AS HIGH AS 31 KT AT JMPN7 THIS EVENING. WINDS OFFSHORE HAVE
REMAINED IN THE 15-20 KT RANGE WITH SEAS AVERAGING AROUND 4 FT.
MSLP GRADIENT SHOULD WEAKEN AS THE FRONT MOVES ACROSS THE WATERS
AFTER 06Z AND MODELS SUGGEST THE POST-FRONTAL GRADIENT WILL REMAIN
SOMEWHAT WEAK. THE MARGINAL SMALL CRAFT ADVISORY WILL REMAIN IN
PLACE NORTH OF LITTLE RIVER FOR THE NEXT SEVERAL HOURS...MAINLY
FOR WINDS NEAR THE IMMEDIATE COAST...BUT MAY BE ABLE TO BE DROPPED BY
08-09Z.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 330 PM FRIDAY...WINDS AND SEAS WILL BE JUST STARTING TO
IMPROVE DAYBREAK SATURDAY...BUT STILL ROUGH...WITH LEFT OVER
SOUTHERLY SWELL ENERGY. THUS AN EXERCISE CAUTION STATEMENT MAY BE
NEEDED EARLY. AS THE WEEKEND PROGRESSES FURTHER IMPROVEMENT IS
EXPECTED. NW WINDS SATURDAY WILL BACK TO W-WSW BY SUNDAY...SPEEDS
GENERALLY 15 KT OR LESS.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 PM FRIDAY...WESTERLY WINDS EXPECTED THROUGH MOST OF THE
LONG TERM...ALTHOUGH SOME UNCERTAINTY EXISTS REGARDING TIMING OF A
FRONTAL BOUNDARY EXPECTED AROUND THE MID WEEK PERIOD. THIS
BOUNDARY MAY COME AS SOON AS MONDAY NIGHT AND ONLY BRING A SMALL
SHIFT FROM SW TO NW WITH ITS PASSAGE. OTHER SOLUTIONS ARE MUCH
SLOWER...AS LATE AS TUESDAY INTO TUESDAY NIGHT. THIS SOLUTION HAS
A STRONGER WAVE OF LOW PRESSURE THAT MAY INTRODUCE A PRECEDENT
SOUTHERLY WIND AND A STRONGER NW WIND IN ITS WAKE. THE PERSISTENCE
OF THE GFS MODEL SHOWING THIS SOLUTION MAKES IT FAIRLY APPEALING
AND THE FORECAST WILL BE NUDGED TOWARDS IT WITHOUT EMBRACING FULLY
IN CASE THE FASTER AND WEAKER SOLUTION PANS OUT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SATURDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...CRM
NEAR TERM...SHK/CRM
SHORT TERM...MJC
LONG TERM...MBB
AREA FORECAST DISCUSSION
NWS RALEIGH NC
318 PM EDT THU MAY 31 2012
.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE AREA WILL GIVE WAY TO A DEVELOPING WARM
FRONT... WHICH WILL HEAD NORTHWARD THROUGH VIRGINIA TONIGHT. A
POWERFUL STORM SYSTEM WILL APPROACH FROM THE WEST FRIDAY... WITH
COLD FRONT PASSAGE LATE FRIDAY EVENING. HIGH PRESSURE WILL BUILD
OVER THE REGION THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM THURSDAY...
THROUGH THIS EVENING: THE MAIN CONCERN FOR THE NEXT SEVERAL HOURS IS
THE LOCATION AND AREAL EXTENT OF ANY STORMS. LATEST SURFACE ANALYSIS
SHOWS A HIGHLY DIFFUSE AND WEAK E-W BOUNDARY ACROSS NRN NC. IT IS
ALONG THIS BOUNDARY THAT SEVERAL MODELS... INCLUDING THE 12KM NAM /
4KM NAM CONUS NEST AND RAP... DEVELOP SCATTERED CONVECTION LATE THIS
AFTERNOON. WHILE THIS LOCATION APPEARS REASONABLE GIVEN THE
ANTECEDENT CONDITIONS... THE LOW MOISTURE HERE (BOTH NEAR THE
SURFACE AND WITH BELOW-NORMAL PRECIPITABLE WATER) AND LIKELIHOOD OF
LITTLE MORE THAN MARGINAL INSTABILITY (ESPECIALLY IN THE MID LEVELS
WHERE AIR REMAINS DRY/WARM WITH WEAK LAPSE RATES) WOULD LIMIT
COVERAGE. ANOTHER SUBTLE BOUNDARY SEPARATING DEW POINTS OF 60-65 TO
ITS SOUTH AND 55-60 TO ITS NORTH STRETCHES ACROSS THE SANDHILLS INTO
THE CENTRAL COASTAL PLAIN. THE LAST SEVERAL HRRR MODEL RUNS HAVE
CONSISTENTLY DEVELOPED A FEW STORMS HERE LATER TODAY... ALSO
REASONABLE CONSIDERING THE CONVECTIVE CLOUDS ALREADY FORMING IN THIS
AREA AND CURRENT MLCAPE OF 500-1000 J/KG. WILL HOLD ONTO A MENTION
OF ISOLATED STORMS IN THE SOUTHEAST SECTIONS AS WELL AS OVER THE
NORTH FOR A FEW HOURS LATE THIS AFTERNOON INTO EARLY THIS EVENING...
BEFORE THE LOSS OF HEATING LEADS TO DISSIPATION WITHIN THE WEAK
SHEAR ENVIRONMENT. SURFACE WINDS ARE EXPECTED TO REMAIN FAIRLY LIGHT
FROM THE SOUTH AND SSW AT 6-10 MPH OVERNIGHT... LEADING TO A
DECOUPLING OF THE LOWER TROPOSPHERE AS 925-850 MB WINDS BEGIN TO
STRENGTHEN OUT OF THE SOUTHWEST TO 25-30 MPH... AND THIS STRONG WARM
AIR ADVECTION JUST OFF THE SURFACE LATE TONIGHT MAY ALLOW US TO
RETAIN ENOUGH ELEVATED INSTABILITY FOR ISOLATED SHOWERS OVERNIGHT...
A SCENARIO PAINTED BY THE HIGH-RES WRF-NMM... ALTHOUGH THIS IS
PREDICATED UPON US SEEING A SUFFICIENT RETURN OF DEEPER MOISTURE AND
HIGHER PW VALUES OVERNIGHT. WITH PW EXPECTED TO BE JUST SLIGHTLY
ABOVE NORMAL AT MOST PRIOR TO DAWN FRIDAY... WILL MENTION JUST
ISOLATED SPRINKLES OVERNIGHT. LOWS IN THE MID TO UPPER 60S LOOK
GOOD. -GIH
&&
.SHORT TERM /FRIDAY AND FRIDAY NIGHT/...
AS OF 315 PM THURSDAY...
...SEVERE STORMS POSSIBLE FRIDAY AFTERNOON AND EVENING...
FOR FRIDAY/FRIDAY NIGHT: THE OVERALL SYNOPTIC ENVIRONMENT AS WELL AS
SEVERAL KEY THERMODYNAMIC AND SHEAR PARAMETERS CONTINUE TO SUPPORT A
GOOD CHANCE OF STRONG TO SEVERE STORMS LATE FRIDAY AFTERNOON THROUGH
MUCH OF THE EVENING. THE DIFFUSE BOUNDARY ACROSS NRN NC THIS
AFTERNOON IS EXPECTED TO HAVE MOVED NORTH OF THE STATE FRIDAY...
PLACING CENTRAL NC FULLY IN THE PREFRONTAL WARM SECTOR. DEEP LAYER
SHEAR IS PREDICTED BY THE MODELS TO STRENGTHEN TO AROUND 30-35 KTS
AS THE DEEPENING MID LEVEL TROUGH... ASSOCIATED WITH THE LOW WHICH
MOVES FROM NEAR CHI NE ACROSS MI... DIGS INTO THE MID SOUTH AND
SWINGS THROUGH THE SRN/CENTRAL APPALACHIANS WITH A NEGATIVE TILT AND
DECENT DPVA OVER WRN/NRN NC. WHILE THE GREATEST MID LEVEL HEIGHT
FALLS WILL OCCUR TO OUR NW... WE WILL STILL SEE 20-50 METER DROPS
THROUGH FRIDAY. DYNAMIC FORCING WILL ALSO BE AUGMENTED BY
STRENGTHENING UPPER DIVERGENCE... INDUCED BY BOTH THE UPPER JET CORE
OVER OH/LAKE HURON AS WELL AS THE STRENGTHENING SUBTROPICAL JET OVER
THE SOUTHEAST STATES. THE AGEOSTROPHIC RESPONSE FROM THIS LATTER JET
AS IT ACCELERATES BY ABOUT 30-35 KTS IN 12 HOURS SHOULD CAUSE THE
UPPER DIVERGENCE TO INCREASE RAPIDLY OVER CENTRAL NC INTO VA BY
AFTERNOON... ADDING TO THE OVERALL ASCENT AND SUPPORT FOR ORGANIZED
STORMS. 850 MB WINDS DO SPEED UP TO 35-45 KTS OVER CENTRAL NC BY
AFTERNOON... ALTHOUGH THE STRONGEST WINDS WILL BE FOUND TO OUR NORTH
THROUGH VA/PA/NY. AS LOW LEVEL TEMPS AND DEW POINTS INCREASE WITH
STEADY OR COOLING MID LEVELS... INSTABILITY IS EXPECTED TO BECOME
MODERATE BY AFTERNOON WITH MODELS INDICATING MLCAPE OF 1000-1800
J/KG... AROUND 500-800 J/KG OF THIS LOCATED IN THE -10C TO -30C
LAYER... SUGGESTIVE OF A LARGE HAIL THREAT WITH ANY STORMS. WHILE
THE 0-1 KM SRH WILL LIKELY BE MAXIMIZED IN THE VICINITY OF THE
NORTHWARD-RETREATING WARM FRONT... 0-1 KM WIND VECTORS AND DERIVED
PARAMETERS SUCH AS THE BULK RICHARDSON NUMBER CONTINUE TO SUPPORT
THE POTENTIAL FOR SUPERCELLS IN CENTRAL NC. AT THE VERY LEAST WE ARE
LIKELY TO SEE AN ORGANIZED SQUALL LINE WITH A RISK OF LARGE HAIL AS
WELL AS DAMAGING WINDS WITHIN BOWING SEGMENTS. THE LATEST MODEL RUNS
CONTINUE TO PLACE THE GREATEST SEVERE RISK OVER THE CENTRAL AND
EASTERN CWA -- ALTHOUGH SEVERE STORMS COULD OCCUR ANYWHERE -- AND
MAINLY BETWEEN THE HOURS OF 4 PM AND 10 PM. HIGHS 84-90 WITH SW
WINDS 10-15 MPH GUSTING TO 22-27 MPH AFTER THE NOCTURNAL JET MIXES
OUT. GRADUAL CLEARING OVERNIGHT AS THE COLD FRONT MOVES EAST OF THE
AREA AND AS THE MID LEVEL VORTICITY LOBE SWINGS BY TO OUR NORTH.
LOWS 58-65. -GIH
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 255 PM THURSDAY...
BASED ON A MODEL CONSENSUS...FRIDAY EVENINGS CONVECTION WILL BE NEAR
THE COAST AT 12Z SATURDAY MORNING AS THE COLD FRONT PUSHES THROUGH
THE COASTAL PLAIN. A TRAILING UPPER JET WILL SURGE SOUTH UNDERNEATH
AN UPPER LOW OVER THE GREAT LAKES AND ACROSS THE TN VALLEY SATURDAY
AND SATURDAY NIGHT. SOME MID AND HIGH CLOUDS SHOULD ACCOMPANY THE
FAST FLOW ALOFT..SO WHILE SKIES SHOULD BE MOSTLY CLEAR IMMEDIATELY
BEHIND THE FRONT SATURDAY...WE WILL SHOW AN INCREASE IN CLOUD COVER
LATE SATURDAY. DESPITE THE UPPER JET AND A SHOT OF MODEST
DPVA...FORECAST SOUNDINGS APPEAR TO BE TOO TABLE AND DRY
FOR MEASURABLE PRECIP...AND THE NAM IS THE ONLY MODEL CURRENTLY
SHOWING ANY LIGHT PRECIP AT ALL. 850MB TEMPS ARE FORECAST TO FALL
TO AROUND 9-10C...AND DRY ADIABATIC MIXING AND LOW LEVEL THICKNESSES
SCHEMES ALL SUGGEST HIGHS UNDER GUIDANCE IN THE UPPER 70S. LOWS
SATURDAY NIGHT IN THE MID 50S. MORE OF THE SAME IS EXPECTED ON
SUNDAY WITH RELATIVELY DRY NORTHWESTERLY FLOW ALOFT....THOUGH WEAK
HEIGHT RISES AND DOWNSLOPE FLOW SHOULD SPRING HIGHS UP INTO THE LOW
TO MID 80S.
AMPLIFIED FLOW WITH AN OMEGA BLOCK IS THEN EXPECTED OVER THE CONUS
NEXT WEEK...LEADING TO EAST AND WEST COAST TROUGHS AND A RIDGE OVER
THE CENTRAL US. NORTHWESTERLY FLOW IS FORECAST TO CONTINUE MONDAY
BEFORE MODELS SHOW VORTICITY SWINGING AROUND THE EAST COAST
TROUGH...SOUTH ACROSS THE MID ATLANTIC STATES TO THE CAROLINAS.
WHILE THERE IS GENERALLY GOOD LARGE SCALE AGREEMENT...THE ECMWF AND
GFS VARY ON THE AMPLITUDE/TIMING OF FORCING AND THE LOCATION OF THE
MEAN FRONTAL ZONE...WHICH SHOULD STRETCH FROM THE SOUTHEAST US TO
THE UPPER MIDWEST. THIS LEADS TO A LOW CONFIDENCE FORECAST
REGARDING THE TIMING AND DURATION OF PRECIP CHANCES FROM LATE MONDAY
THROUGH THE END OF THE PERIOD. HIGHS ARE EXPECTED TO BE AROUND
NORMAL MONDAY IN THE MID 80S...FALLING TO SLIGHTLY BELOW NORMAL WITH
INCREASING PRECIP CHANCES THROUGH MID WEEK.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 120 PM THURSDAY...
VFR CONDITIONS WILL HOLD OVER CENTRAL NC THROUGH TONIGHT... WITH
WEAK HIGH PRESSURE AND A DRY AIR MASS OVER THE REGION. VERY ISOLATED
AND CIRCUMNAVIGABLE STORMS MAY DEVELOP PRIMARILY NEAR FAY BUT ALSO
POSSIBLE NEAR RDU/RWI BETWEEN 20Z THIS AFTERNOON AND 01Z THIS
EVENING... AND THE TYPICAL VARIABLE/GUSTY WINDS NEAR STORMS AND MVFR
CONDITIONS BENEATH STORMS ARE A SLIM POSSIBILITY... HOWEVER THE VAST
MAJORITY OF THE DAY EVEN AT THIS SPOTS WILL REMAIN VFR. VSBYS/CIGS
WILL STAY VFR TONIGHT... HOWEVER THERE IS A CHANCE OF BORDERLINE LOW
LEVEL WIND SHEAR CONDITIONS (MAINLY SPEED SHEAR) FROM 07Z-13Z FRIDAY
MORNING AT ALL CENTRAL NC LOCATIONS... AS NEAR-SURFACE WINDS FROM
THE S AND SSW AT 5-9 KTS ARE TOPPED BY SWRLY WINDS OF 25-30 KTS AT
1800-2500 FT AGL. THIS LOW LEVEL JET WILL MIX OUT WITH HEATING SOON
AFTER DAYBREAK FRIDAY. AN APPROACHING COLD FRONT WILL BRING
WIDESPREAD STRONG THUNDERSTORMS FRIDAY AFTERNOON... BUT MAINLY AFTER
THE END OF THIS TERMINAL AERODROME FORECAST VALID PERIOD.
LOOKING BEYOND 18Z FRIDAY... CONFIDENCE IS HIGH THAT CENTRAL NC
AIRPORTS WILL BE AFFECTED BY STRONG STORMS AHEAD OF A COLD FRONT
LATE FRIDAY AFTERNOON INTO THE EVENING... ESPECIALLY FROM 20Z
THROUGH 03Z. LARGE HAIL OVER 1 INCH IN DIAMETER AND SURFACE WIND
GUSTS TO OVER 60 KTS ARE POSSIBLE. AVIATION INTERESTS SHOULD PAY
CLOSE ATTENTION TO THE LATEST CONDITIONS AND FORECASTS FRIDAY
AFTERNOON/EVENING. MVFR CIGS MAY BRIEFLY LINGER BEHIND THE COLD
FRONT LATE FRIDAY NIGHT. VFR CIGS ARE EXPECTED LATE SATURDAY THROUGH
SUNDAY DUE TO UPPER LEVEL DISTURBANCES PASSING OVERHEAD. CONDITIONS
WILL REMAIN VFR THROUGH MONDAY... THEN ADDITIONAL DISTURBANCES AND A
BACKDOOR COOL FRONT MAY BRING MVFR CONDITIONS MONDAY NIGHT/TUESDAY.
-GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
102 AM CDT THU MAY 31 2012
.DISCUSSION...
THE OVERALL FORECAST IS WELL ON TRACK...WITH ONLY MINIMAL CHANGES
REQUIRED TO BLEND TO THE LAST EST 06 UTC OBSERVED TRENDS. DID ADD A
SLIGHT CHANCE MENTION OF SHOWERS TO THE FAR SOUTHWEST OVERNIGHT
WITH THE LATEST RUNS OF THE HRRR SUPPORTING THE PROPAGATION OF
ONGOING SHOWER ACTIVITY ACROSS SOUTHEAST MONTANA INTO THE FAR
SOUTHWEST PORTIONS OF NORTH DAKOTA. DID MAINTAIN A MENTION OF
PATCHY FOG FOR LOCATIONS IMPACTED BY RAINFALL YESTERDAY. THE
CURRENT FROST ADVISORY LOOKS GOOD...WITH NO CHANGES REQUIRED.
&&
.AVIATION...
AT MIDNIGHT CDT...HIGH PRESSURE CENTERED NEAR MOBRIDGE
SOUTH DAKOTA IS EXPECTED TO REMAIN NEARLY STATIONARY OVERNIGHT. THE
FORECAST IS FOR VFR CONDITIONS AT ALL TAF SITES THROUGH 7 PM CDT
THURSDAY. ALTHOUGH VFR IS EXPECTED...ONE UNCERTAINTY IS THE ABUNDANT
LOW LEVEL MOISTURE FROM THE RECENT RAIN SOUTHWEST AND SOUTH CENTRAL.
WITH MAINLY CLEAR SKIES AND LIGHT WINDS THERE IS AN INCREASE THE FOG
POSSIBILITY. SO EXPECT KDIK/KBIS TO HAVE SOME LOCAL OR VICINITY FOG
BETWEEN 09Z/4 AM CDT AND 14Z/9 AM CDT. MENTIONED VCFG THERE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
FROST ADVISORY UNTIL 9 AM CDT /8 AM MDT/ THIS MORNING FOR
NDZ018>020-033>036-041-042-044>047-050.
&&
$$
UPDATE...AYD
AVIATION...WAA
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1218 PM CDT THU MAY 31 2012
.UPDATE...
UPDATED TO INCLUDE 18Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION...
UPDATE... /ISSUED 1015 AM CDT THU MAY 31 2012/
CURRENT FORECAST IS ON TRACK AT THIS TIME. NO UPDATES TO GRIDS AS
OF THIS MOMENT. SEE BELOW FOR UPDATED DISCUSSION ON SEVERE WEATHER
POTENTIAL.
RRH
AS OF 10 AM...CONDITIONS ACROSS THE MIDSOUTH RANGED FROM MOSTLY
CLEAR ACROSS THE TENNESSEE RIVER VALLEY TO MOSTLY CLOUDY ACROSS
THE MAJORITY OF NORTHERN MISSISSIPPI AND EASTERN ARKANSAS. THE SUN
HAS BEEN OUT FOR MOST OF THE MORNING ACROSS WESTERN TENNESSEE AND
NORTHEASTERN MISSISSIPPI. SOME ADDITIONAL CLEARING IS VISIBLE ON
SATELLITE OVER WESTERN MISSISSIPPI...SOUTHERN ARKANSAS...AND
NORTHERN LOUISIANA. A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
OVER NORTHEASTERN ARKANSAS BUT THESE STORMS HAVE POSED NO THREAT
OF SEVERE WEATHER SO FAR.
THE INSTABILITY WILL GRADUALLY INCREASE THROUGH THE REST OF THE
MORNING AND EARLY AFTERNOON HOURS IN AREAS WHERE CLOUD COVER HAS
CLEARED. MODELS ARE INDICATING CAPE VALUES BETWEEN 2000 J/KG TO
3000 J/KG WILL BE POSSIBLE BY EARLY THIS AFTERNOON. LATEST RUN OF
THE NAM MODEL HAS INITIALIZED WELL AND IS HANDLING THE CURRENT
CONVECTION OVER MISSOURI AND TEXAS WITH GOOD ACCURACY. GOING BY
THIS MODEL...CONVECTION WILL RAPIDLY INCREASE ACROSS ARKANSAS
BETWEEN THE HOURS OF NOON AND 2 PM. THIS AREA OF THUNDERSTORMS
WILL MOVE ACROSS THE MIDSOUTH THIS AFTERNOON AND CLEAR THE REGION
BY THIS EVENING. A FEW SHOWERS MAY DEVELOP ALONG THE COLD FRONT
THIS EVENING BUT THE SEVERE WEATHER SHOULD HAVE CLEARED OUT BY
THEN. THE MAIN THREATS FOR THIS AFTERNOONS STORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. TORNADOES DO NOT SEEM LIKELY ACROSS THE
MAJORITY OF THE MIDSOUTH AT THIS TIME DUE TO A UNIDIRECTIONAL WIND
FIELD. HOWEVER...AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM...AN
ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT FOR NORTHWEST
TENNESSEE AND THE MISSOURI BOOTHEEL. THIS IS BECAUSE THE SURFACE
WINDS WILL REMAIN BACKED TO THE SOUTHEAST A LITTLE LONGER ACROSS
THIS AREA OF CONCERN THAN THE REST OF THE MIDSOUTH. SOUNDINGS FOR
TODAY SHOW DRIER AIR IN THE LOWER ATMOSPHERE WITH DOWNDRAFT CAPE
VALUES AS HIGH AS 1000 J/KG TO 1500 J/KG...WHICH WOULD INDICATE A
BETTER POTENTIAL FOR DAMAGING WINDS. STEEP LOW LEVEL LAPSE RATES
WILL ALLOW FOR STRONG UPDRAFTS...WHICH WILL SOMEWHAT INCREASE THE
HAIL POTENTIAL.
RRH
PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
18Z TAF CYCLE (31/18Z-01/18Z)
NUMEROUS THUNDERSTORMS ARE EXPECTED TO SPREAD INTO AND DEVELOP
ACROSS THE MIDSOUTH THIS AFTERNOON AS AN UPPER LEVEL TROUGH AND
ASSOCIATED COLD FRONT APPROACH FROM THE WEST. A FEW STORMS MAY BE
SEVERE WITH DAMAGING WINDS AND LARGE HAIL. THUNDERSTORMS GRADUALLY
ENDING FROM THE WEST THIS EVENING AND OVERNIGHT. SOUTHWEST WINDS
10-12 KTS WITH OCCASIONAL GUSTS TO NEAR 18 KTS WILL PREVAIL THIS
AFTERNOON. WIND TURNING TO THE NORTHWEST AND NORTH TONIGHT AT 12
KTS WITH GUSTS TO 18 KTS. MVFR CEILINGS SPREADING INTO THE AREA
TONIGHT BEHIND THE COLD FRONT GRADUALLY CLEARING AT KMEM AND KJBR
AFTER 01/13-15Z.
JCL
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 57 74 58 83 / 50 10 0 20
MKL 55 73 48 81 / 60 10 0 10
JBR 55 74 54 82 / 30 10 10 20
TUP 62 76 53 83 / 80 10 0 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1015 AM CDT THU MAY 31 2012
.UPDATE...
CURRENT FORECAST IS ON TRACK AT THIS TIME. NO UPDATES TO GRIDS AS
OF THIS MOMENT. SEE BELOW FOR UPDATED DISCUSSION ON SEVERE WEATHER
POTENTIAL.
RRH
&&
.DISCUSSION...
AS OF 10 AM...CONDITIONS ACROSS THE MIDSOUTH RANGED FROM MOSTLY
CLEAR ACROSS THE TENNESSEE RIVER VALLEY TO MOSTLY CLOUDY ACROSS
THE MAJORITY OF NORTHERN MISSISSIPPI AND EASTERN ARKANSAS. THE SUN
HAS BEEN OUT FOR MOST OF THE MORNING ACROSS WESTERN TENNESSEE AND
NORTHEASTERN MISSISSIPPI. SOME ADDITIONAL CLEARING IS VISIBLE ON
SATELLITE OVER WESTERN MISSISSIPPI...SOUTHERN ARKANSAS...AND
NORTHERN LOUISIANA. A FEW SHOWERS AND THUNDERSTORMS HAVE DEVELOPED
OVER NORTHEASTERN ARKANSAS BUT THESE STORMS HAVE POSED NO THREAT
OF SEVERE WEATHER SO FAR.
THE INSTABILITY WILL GRADUALLY INCREASE THROUGH THE REST OF THE
MORNING AND EARLY AFTERNOON HOURS IN AREAS WHERE CLOUD COVER HAS
CLEARED. MODELS ARE INDICATING CAPE VALUES BETWEEN 2000 J/KG TO
3000 J/KG WILL BE POSSIBLE BY EARLY THIS AFTERNOON. LATEST RUN OF
THE NAM MODEL HAS INITIALIZED WELL AND IS HANDLING THE CURRENT
CONVECTION OVER MISSOURI AND TEXAS WITH GOOD ACCURACY. GOING BY
THIS MODEL...CONVECTION WILL RAPIDLY INCREASE ACROSS ARKANSAS
BETWEEN THE HOURS OF NOON AND 2 PM. THIS AREA OF THUNDERSTORMS
WILL MOVE ACROSS THE MIDSOUTH THIS AFTERNOON AND CLEAR THE REGION
BY THIS EVENING. A FEW SHOWERS MAY DEVELOP ALONG THE COLD FRONT
THIS EVENING BUT THE SEVERE WEATHER SHOULD HAVE CLEARED OUT BY
THEN. THE MAIN THREATS FOR THIS AFTERNOONS STORMS WILL BE DAMAGING
WINDS AND LARGE HAIL. TORNADOES DO NOT SEEM LIKELY ACROSS THE
MAJORITY OF THE MIDSOUTH AT THIS TIME DUE TO A UNIDIRECTIONAL WIND
FIELD. HOWEVER...AHEAD OF A DEVELOPING LOW PRESSURE SYSTEM...AN
ISOLATED TORNADO OR TWO CAN NOT BE RULED OUT FOR NORTHWEST
TENNESSEE AND THE MISSOURI BOOTHEEL. THIS IS BECAUSE THE SURFACE
WINDS WILL REMAIN BACKED TO THE SOUTHEAST A LITTLE LONGER ACROSS
THIS AREA OF CONCERN THAN THE REST OF THE MIDSOUTH. SOUNDINGS FOR
TODAY SHOW DRIER AIR IN THE LOWER ATMOSPHERE WITH DOWNDRAFT CAPE
VALUES AS HIGH AS 1000 J/KG TO 1500 J/KG...WHICH WOULD INDICATE A
BETTER POTENTIAL FOR DAMAGING WINDS. STEEP LOW LEVEL LAPSE RATES
WILL ALLOW FOR STRONG UPDRAFTS...WHICH WILL SOMEWHAT INCREASE THE
HAIL POTENTIAL.
RRH
&&
PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
12Z TAF CYCLE
A DIFFICULT FORECAST ONCE AGAIN FOR TODAY AS MULTIPLE MESOSCALE
FEATURES MAY DOMINATE THE EVOLUTION OF THE OVERALL PATTERN OVER
THE NEXT 24 HOURS. THIS RESULTS IN LOWER THAN PREFERRED FORECAST
CONFIDENCE.
A DECAYING MCS CONTINUES TO MOVE EAST WITH AN OUTFLOW BOUNDARY
THAT SHOULD WEAKEN AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST BY MID MORNING. LATEST HIGH RESOLUTION RAPID REFRESH MODEL
RUN WHICH HANDLED OVERNIGHT CONVECTION BEST INDICATES AT LEAST
SCATTERED DEVELOPMENT ALONG THIS EASTWARD MOVING OUTFLOW BOUNDARY.
PLAN TO MAINTAIN A VCTS BEGINNING AT 14Z AT JBR AND CONTINUING
INTO AFTERNOON POINTS FURTHER EAST. WINDS SHOULD INITIALLY BE
SOUTHEASTERLY AND LIGHT BUT VEER TO THE SOUTH AND EVENTUALLY
SOUTHWEST BY THIS AFTERNOON AND INCREASE IN INTENSITY.
AT THIS TIME...IT APPEARS THAT THE GREATEST THUNDERSTORM POTENTIAL
WILL HOLD OFF UNTIL THIS AFTERNOON AS A RATHER WELL DEFINED
SHORTWAVE OVER EASTERN OKLAHOMA THIS MORNING MOVES EAST INTO THE
REGION. HAVE MAINTAINED TEMPO GROUPS FOR STORMS THROUGH THE
AFTERNOON AND EARLY EVENING HOURS FROM WEST TO EAST AT ALL SITES.
THUNDERSTORM POTENTIAL SHOULD END FROM WEST TO EAST DURING THE
EVENING HOURS AS A COLD FRONT SWEEPS EAST ACROSS THE AREA. WINDS
SHOULD COME OUT OF THE NORTHWEST AND NORTH WITH SOME GUSTS
OVERNIGHT BEHIND THE FRONTAL PASSAGE.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
715 AM CDT THU MAY 31 2012
.UPDATE...
UPDATED FOR THE 12Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 353 AM CDT THU MAY 31 2012/
DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
12Z TAF CYCLE
A DIFFICULT FORECAST ONCE AGAIN FOR TODAY AS MULTIPLE MESOSCALE
FEATURES MAY DOMINATE THE EVOLUTION OF THE OVERALL PATTERN OVER
THE NEXT 24 HOURS. THIS RESULTS IN LOWER THAN PREFERRED FORECAST
CONFIDENCE.
A DECAYING MCS CONTINUES TO MOVE EAST WITH AN OUTFLOW BOUNDARY
THAT SHOULD WEAKEN AS IT MOVES INTO THE FORECAST AREA FROM THE
WEST BY MID MORNING. LATEST HIGH RESOLUTION RAPID REFRESH MODEL
RUN WHICH HANDLED OVERNIGHT CONVECTION BEST INDICATES AT LEAST
SCATTERED DEVELOPMENT ALONG THIS EASTWARD MOVING OUTFLOW BOUNDARY.
PLAN TO MAINTAIN A VCTS BEGINNING AT 14Z AT JBR AND CONTINUING
INTO AFTERNOON POINTS FURTHER EAST. WINDS SHOULD INITIALLY BE
SOUTHEASTERLY AND LIGHT BUT VEER TO THE SOUTH AND EVENTUALLY
SOUTHWEST BY THIS AFTERNOON AND INCREASE IN INTENSITY.
AT THIS TIME...IT APPEARS THAT THE GREATEST THUNDERSTORM POTENTIAL
WILL HOLD OFF UNTIL THIS AFTERNOON AS A RATHER WELL DEFINED
SHORTWAVE OVER EASTERN OKLAHOMA THIS MORNING MOVES EAST INTO THE
REGION. HAVE MAINTAINED TEMPO GROUPS FOR STORMS THROUGH THE
AFTERNOON AND EARLY EVENING HOURS FROM WEST TO EAST AT ALL SITES.
THUNDERSTORM POTENTIAL SHOULD END FROM WEST TO EAST DURING THE
EVENING HOURS AS A COLD FRONT SWEEPS EAST ACROSS THE AREA. WINDS
SHOULD COME OUT OF THE NORTHWEST AND NORTH WITH SOME GUSTS
OVERNIGHT BEHIND THE FRONTAL PASSAGE.
JLH
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
353 AM CDT THU MAY 31 2012
.DISCUSSION...FORECAST FOCUS ON CONVECTIVE POTENTIAL TODAY.
.SHORT TERM...TODAY THROUGH FRIDAY NIGHT.
A VERY COMPLEX CONVECTIVE SCENARIO IS BEGINNING TO UNFOLD ACROSS
THE LOWER MISSISSIPPI VALLEY TODAY. ONE COMPLEX OVER SOUTHERN
MISSOURI IS HEADED MAINLY EAST ALONG THE SYNOPTIC WARM FRONT. ANOTHER
MCS LOCATED OVER NORTHEAST TEXAS IS HEADED MORE EAST/SOUTHEAST
DUE TO A NUMBER OF COLD POOL INTERACTIONS - ONE FROM THAT COMPLEX
ITSELF AND ANOTHER FROM YESTERDAYS STORMS OVER NORTHERN
MISSISSIPPI. HI-RES RAPID REFRESH MODEL INDICATES THE NORTHERN
COMPLEX DIMINISHING THIS MORNING WITH THE SOUTHERN ONE EXPANDING
AND EVENTUALLY TURNING DUE SOUTH THRU ERN TX/WRN LA. THIS TREND
IS ALREADY BEING SEEN WITH MORE STORMS FIRING OVER THE DFW
METROPLEX. BETWEEN THE NORTHERN COMPLEX DYING AND THE SOUTHERN ONE
TURNING MORE SOUTH WITH TIME...THINK THE MIDSOUTH WILL BE SPARED
FROM MUCH CONVECTION THIS MORNING. HOWEVER...AS INSTABILITY
INCREASES BY MIDDAY WITH MID LEVEL HEIGHT FALLS AND LITTLE OR NO
CAPPING...THINK NUMEROUS THUNDERSTORMS WILL REDEVELOP AHEAD OF THE
FRONT...POSSIBLY CONGEALING INTO CLUSTERS OR LINE SEGMENTS CAPABLE
OF MAINLY WIND DAMAGE. HRRR SHOWS THIS QUITE WELL. ONE VERY REAL
CONCERN IS WHETHER THE COLD POOL FROM YESTERDAY AND THE LARGE COLD
POOL TO THE WEST WILL SQUASH DEVELOPMENT THIS AFTERNOON. STILL A
LOT OF UNCERTAINTY BUT STAYED THE COURSE WITH VERY HIGH POPS THIS
AFTERNOON...WHICH IS CONSIDERABLY ABOVE MOS GUIDANCE.
SHOWERS AND STORMS WILL CLEAR TO THE EAST THIS EVENING WITH
DECREASING CLOUDS...GUSTY NORTH WINDS...AND COOL TEMPERATURES
OVERNIGHT.
A VERY PLEASANT DAY ON TAP FOR FRIDAY WITH BREEZY NORTHWEST WINDS
AND TEMPERATURES ONLY IN THE LOW TO MID 70S. LOWS FRIDAY NIGHT
LOOK TO DROP INTO THE 40S EAST AND LOW TO MID 50S WEST. MAY BE
ONE OF THE COOLEST DAYS FOR THE NEXT FEW MONTHS.
.LONG TERM...SATURDAY THROUGH WEDNESDAY.
A RIDGE WILL BUILD OVER THE PLAINS FOR THE WEEKEND AND KEEP THE
MIDSOUTH IN A NORTHWEST FLOW FOR THE EXTENDED. SEVERAL
DISTURBANCES WITHIN THE NORTHWEST FLOW WILL BRING CHANCES FOR
THUNDERSTORMS DURING THIS PERIOD. BEST CHANCES APPEAR TO BE SUNDAY
THROUGH MONDAY NIGHT SO BUMPED UP POPS TO THE 30-40 PCT RANGE.
OTHERWISE...EARLY SUMMERLIKE TEMPERATURES CAN BE EXPECTED.
BORGHOFF
&&
.AVIATION...
06Z TAF SET
COLD FRONT WILL MOVE INTO THE CWA AFTER 16Z. EXPECT TSRAS TO DEVELOP
ALONG AND AHEAD OF THE FRONT. HAVE TEMPOS AT EACH TAF SITE FOR BEST
TIME PERIOD OF SEEING TSRAS. THE TSRAS MAY TEMPORARILY BRING MVFR OR
LOWER CONDITIONS BUT OTHERWISE EXPECT VFR CONDITIONS OVER THE NEXT
24 HOURS. LIGHT WINDS WILL BECOME SW AT 10-12 KTS AHEAD OF THE
FRONT. BEHIND THE FRONT WINDS WILL SWITCH TO THE NW.
KRM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 84 57 74 58 / 80 50 10 0
MKL 84 55 73 48 / 80 60 10 0
JBR 81 55 74 54 / 80 30 0 0
TUP 88 62 76 53 / 70 80 10 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1154 PM CDT WED MAY 30 2012
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT SHWRS/TSTM 31/16Z-01/00Z. MVFR
FOG POSSIBLE CSV...OTHERWISE VFR/SKC CONDITIONS THRU 31/16Z.
EXPECT INCREASING DIURNAL BASED UNSTABLE ATM TO SUPPORT SCT TO
NUMEROUS SHWRS/TSTMS BY 31/22Z...BUT WITH SOME UNCERTAINTIES
PER LOCATION DEVELOPMENT DUE TO DEVELOPMENT BEING MAINLY DIURNAL
DRIVEN IN NATURE...WILL MENTION VCTS/CB REMARKS IN TAFS THRU 01/01Z.
EXPECT BKN VFR CB BASED CEILINGS BY 01/01Z ALSO...BUT TEMP MVFR
/IFR/LIFR CEILINGS POSSIBLE. BEST POTENTIAL FOR MVFR VSBYS/CEILINGS
AT OR AFTER 01/00Z AS SFC FRONTAL DYNAMICS SLOWLY APPROACH AREA.
&&
.PREV DISCUSSION.../ISSUED 706 PM CDT WED MAY 30 2012/
UPDATE...
LAPS CAP CONTINUES TO EXPAND THIS EVENING WHILE CAPES ARE ON THE
DOWNSWING. GIVEN THE ISC STATUS AND LATEST SHORT TERM QPF
EXPECTATIONS OVERNIGHT...WILL GO AHEAD AND SLASH POPS FOR ALL BUT
THE WESTERN QUARTER OF THE MID STATE. WILL KEEP 20 POPS GOING
ACROSS THE FAR WEST GIVEN THE SLIGHT MOISTURE ENHANCEMENT THAT IS
EXPECTED TOWARD 12Z FOR THAT AREA.
OTW...WILL INCREASE CLOUD COVERAGE ACROSS THE SOUTH FOR THIS
EVENING...GIVEN THE UPPER LEVEL BLOW OFF FROM THE WEAKENING STORMS
TO OUR SW. REMAINDER OF THE FORECAST...LOOKS TO BE IN GOOD SHAPE.
PREV DISCUSSION... /ISSUED 611 PM CDT WED MAY 30 2012/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
UNCERTAINTIES...AREAL DEVELOPMENT OF SHWRS/TSTM 31/16Z-31/24Z.
EXPECT SCT AC/CI THRU 31/14Z WITH MVFR FOG POSSIBLE CSV PER LOW
LEVEL MOISTURE POOLING...CALM WINDS...AND CLRING SKIES. EXPECT
INCREASING UNSTABLE ATM TO SUPPORT SCT TO NUMEROUS SHWRS/TSTMS
BY 31/24Z...BUT WITH SOME UNCERTAINTIES PER LOCATION DEVELOPMENT
DUE TO DEVELOPMENT BEING MAINLY DIURNAL DRIVEN IN NATURE...THUS
WILL MENTION VCTS/CB REMARKS IN TAFS ONLY. EXPECT BKN VFR CB
BASED CEILINGS BY 31/24Z...BUT TEMP MVFR/IFR/LIFR CEILINGS POSSIBLE.
PREV DISCUSSION.../ISSUED 459 PM CDT WED MAY 30 2012/
UPDATE...
WRF...NAM AND GFS ARE ALL VIRTUALLY BONE DRY OVERNIGHT. RUC STILL
TRYING TO HANG ON TO CONVECTION WHICH HAS YET TO OCCUR. CURRENT
FCST IS IN THE 20-30 PERCENT RANGE. CONVECTION COULD STILL FIRE
BUT ITS LOOKING LESS AND LESS LIKELY.
THE PLAN FOR TONIGHT WILL BE TO GIVE THE CONVECTION CHANCES
ANOTHER HOUR OR TWO BEFORE WITHDRAWING THE OVERNIGHT POPS.
OVERNIGHT UPPER DIVERGENCE AND MOISTURE LEVELS ARE HELD AT
BAY. HOWEVER...MAY KEEP A SLIGHT CHANCE GOING ACROSS OUR SOUTHWEST AS PER
THE CURRENT PROXIMITY OF THIS AFTERNOONS CONVECTION.
OTW...QUIET NIGHT...ESPECIALLY COMPARED TO WHAT MAY BE TOMORROW AT
THIS TIME.
NO UPDATE AT THIS MOMENT...BUT LOOK FOR UPDATE WITH THE NEXT FEW HOURS.
PREV DISCUSSION.../ISSUED 311 PM CDT WED MAY 30 2012/
DISCUSSION...
AIR MASS SOMEWHAT STABLE THIS AFTERNOON ACROSS THE TENNESSEE
VALLEY WITH TEMPS IN THE 80S. DRIER AIR ALOFT HAS MIXED DOWN TO
THE SURFACE. WILL HAVE SMALL POPS IN FOR TONIGHT BUT THINK WE WILL
HAVE TO WAIT ON BOUNDARY TO OUR SOUTH TO LIFT NORTHWARD INTO
TENNESSEE THURSDAY MORNING TO PROVIDE FOCUS. EXPECT WE WILL SEE
SHOWERS AND STORMS ON THE INCREASE THURSDAY ESPECIALLY BY
AFTERNOON IN MOST AREAS. SHOWERS AND STORMS LOOK CATEGORICAL
THURSDAY NIGHT...ESPECIALLY EVENING. SOME STORMS COULD BE SEVERE
IN THE MID STATE LATE AFTERNOON AND THURSDAY EVENING AS SURFACE
LOW UNDERGOES CYCLOGENSIS AS IT ROLLS EAST FROM OKLAHOMA ON
THURSDAY AND INTO THE TENNESSEE AND OHIO VALLEYS BY LATE IN THE
DAY THURSDAY. WIND PROFILES WOULD SUGGEST DAMAGING WINDS AND LARGE
HAIL TO BE THE MAIN THREAT. RAIN SHOULD END FROM THE WEST FRIDAY
MORNING WITH HIGH PRESSURE WORKING INTO THE AREA FROM MISSOURI. A
DIRTY SURFACE RIDGE WILL BE OVER THE TENNESSEE VALLEY FOR THE NEXT
SEVERAL DAYS AS UPPER TROUGH RULES...WITH NO SIGNIFICANT RAIN
CHANCE UNTIL ABOUT TUESDAY OF NEXT WEEK AND THEN MODELS HAVE
FAIRLY LOW QPF.
AND NOW A LITTLE TRIVIA: NASHVILLE IS ON PACE TO HAVE THE 6TH
WARMEST MAY ON RECORD AND THE WARMEST SINCE 1991. NASHVILLE HAD
TWO DAYS OF 95 DEGREE HEAT THIS MONTH. THE HOTTEST TEMPERATURE
EVER RECORDED IN THE MONTH OF MAY IS 96 BACK IN 1937.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
309 PM CDT THU MAY 31 2012
.SHORT TERM (TONIGHT THROUGH FRIDAY)...OUTFLOW BOUNDARY HAS
REACHED VICTORIA. HOWEVER...SO FAR IT LOOKS LIKE THE CAP AND
NEGATIVE H85 THEATA-E ADVECTION IS WINNING OUT WITH LACK OF
CONVECTION ALONG THE OUTFLOW BOUNDARY ACROSS OUR NE CWA AND
EWX CWA. STILL THE POTENTIAL THROUGH THE LATE AFTERNOON AND
EVENING ACROSS MAINLY THE NORTHWEST CWA FOR CONVECTION TO
DEVELOP WHERE CAP ERODES AND BETTER LOW LEVEL CONVERGENCE IS
SITUATED. IN ADDITION...4 KM NMM AND HRRR HINTING AT CONVECTION
DEVELOPING ACROSS MEXICO POSSIBLY MAKING IT INTO WESTERN CWA LATER
THIS EVENING. WILL KEEP LOW CHANCE POPS IN THE FORECAST THIS
EVENING ALONG AND WEST OF A GEORGE WEST TO HEBBRONVILLE
LINE...WITH 10-20 POPS EAST OF THIS LINE. STILL SUFFICIENT
INSTABILITY AND SHEAR THAT SHOULD STORMS DEVELOP ACROSS THE BRUSH
COUNTRY OR RIO GRANDE PLAINS THEY COULD BECOME STRONG TO SEVERE.
EVENTUALLY THE WEAK BOUNDARY/FRONT WILL STALL OVER THE AREA
OVERNIGHT AND WASH OUT FRIDAY AFTERNOON. WILL MAINTAIN INHERITED
10-20 POPS IN THE FORECAST DURING THE DAY FRIDAY...ALTHOUGH
FORCING APPEARS PRETTY WEAK.
&&
.LONG TERM (FRIDAY NIGHT THROUGH THURSDAY)...DRYING IN THE LOWER
LEVELS WILL LEAD TO A DRY WEEKEND. MODELS ARE IN AGREEMENT WITH AN
UPPER LEVEL CLOSED LOW DEVELOPING ALONG THE WESTERN COAST OF MEXICO.
MODELS PROG THE LOW TO TREK NORTHEAST OVER THE SIERRA MADRE TO THE
RIO GRANDE SOUTH OF THE BIG BEND AREA THROUGH EARLY NEXT WEEK. THIS
WILL BRING MOISTURE TO THE MID AND UPPER LEVELS OF THE ATMOSPHERE...
WITH INCREASING HIGH CLOUDS. SURFACE HIGH OVER THE NORTHERN GULF AND
DEVELOPING LOW OVER THE SOUTHERN PLAINS WILL ALLOW FOR A MODERATE
SOUTHEASTERLY FLOW TO DEVELOP EACH AFTERNOON THROUGH THE
WEEK...BRINGING MOISTURE BACK TO THE LOW LEVELS. HOWEVER...CAPPING
REMAINS QUITE STRONG...WITH BEST MOISTURE IN THE LOW LEVELS...
LEADING TO POSSIBLY ISOLATED SHOWERS IN THE MORNING...WITH ISOLATED
THUNDERSTORM ACTIVITY POSSIBLE IN THE AFTERNOON ALONG THE DEVELOPING
SEABREEZE EACH AFTERNOON THROUGH THE END OF THE EXTENDED. A BIT MORE
COVERAGE WILL BE POSSIBLE AS THE UPPER LOW SHIFTS TO THE
NORTHEAST...THO WILL ALL BE DEPENDENT ON IF THE CAP CAN WEAKEN WELL
ENOUGH. WITH NO STRONG UPPER LEVEL DIFFLUENCE ALOFT...NO STRONG
STORMS ARE EXPECTED AT THIS TIME. OVERALL...TEMPERATURES WILL REMAIN
WARM WITH SIMILARITIES AS THE PAST COUPLE OF DAYS. DUE TO WARM H85
TEMPS MIXING DOWN EACH AFTERNOON...KEPT ABOVE GUIDANCE THROUGH THE
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 75 90 73 91 76 / 10 10 10 10 10
VICTORIA 72 93 71 93 73 / 20 20 10 10 10
LAREDO 76 97 76 100 76 / 40 20 10 10 10
ALICE 74 95 72 97 74 / 20 20 10 10 10
ROCKPORT 78 89 77 88 78 / 10 10 10 10 10
COTULLA 73 95 70 99 73 / 40 20 10 10 10
KINGSVILLE 75 93 73 93 75 / 10 20 10 10 10
NAVY CORPUS 78 89 77 89 78 / 10 10 10 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
JR/76...SHORT TERM
CB/85...LONG TERM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
513 PM PDT Fri Jun 1 2012
.SYNOPSIS...
The weekend will get off to a wet start as a strong and moist
cold front will promote widespread showers and breezy
conditions. The latter half of the weekend will see drier
conditions. Temperatures will remain near or cooler than normal
for this time of year. A brief warm-up is expected on Monday ahead
of a strong cold front. This front will likely deliver some
thunderstorms on Monday into Monday evening. The remainder of the
week will see a progressive pattern with occasional showers and
cooler than normal temperatures.
&&
.DISCUSSION...
Tonight and Saturday...Satellite imagery this afternoon indicated
a cold front along 130W with models showing this front to move
rapidly eastward into the Inland Northwest overnight tonight into
Saturday morning. The front will cross the Cascades overnight into
Eastern Washington, reaching the Idaho Panhandle late tonight into
Saturday morning. Prior to the front passage a moist and somewhat
unstable air mass will result in scattered showers over northeast
Washington and the Idaho Panhandle as well as the East Slopes of
the Cascades. LAPS data from this afternoon indicated CAPES of
200-600 J/KG over the Blues, Northeast Washington Mountains and
Idaho Panhandle. However visible satellite trends and HRRR argue
for only a minimal thunder threat so opted to remove the
thunderstorm wording this evening.
Then as the cold front crosses the Cascades a right entrance
region of an upper jet will result in added lift such that bands
of showers will likely develop over North Central Washington with
this activity moving east during the night as the front and jet
move east. Meanwhile...the most intense showers are expected over
the Blues Mountains, Lewiston area, and Camas Prairie as an area of
elevated instability passes through. Could see isolated
thunderstorms in these areas overnight into Saturday morning.
Behind the front a pronounced dry slot will bring clearing from
west to east on Saturday. This will be especially pronounced in
the lee of the Cascades with a mostly sunny and breezy day
expected. Over the Northeast Washington Mountains and Idaho
Panhandle lingering instability in the afternoon will likely
trigger additional post frontal shower activity along with a
slight chance of thunderstorms. JW
Saturday night through Monday...Strong upper level low is expected to
remain parked over the Gulf of Alaska through the weekend.
Various disturbances will wrap around the eastern periphery of the
low...but the brunt of the energy will generally skirt the region.
Models are in good agreement that the first disturbance will drift
inside of 130w by 12z Sunday then continue northeast and weaken as
it heads across western Washington. Potential instability with
this system looks rather paltry while much of the moisture is
confined above 700 mbs. Suspect the main impact will be an
increasing cloud trend as well as a chance of light rain showers
or sprinkles...with the best chances occurring over the SE portion
of the forecast area. The models have been backing off of late on
the QPF amounts and if this continues...pops may need to be
lowered even further.
By late Sunday night and into Monday...the pattern becomes much more
interesting as the aforementioned Gulf of Alaska low drops south
and east...turning the mean flow to more of a southerly
orientation. The n-s oriented upper level jet is expected to
bisect Washington by late afternoon...with the eastern third of
Washington and the Idaho Panhandle under the strongly diffluent
upper level flow. This flow will coincide with a rapid
destabilization the lower atmosphere warms in response to the low-
level southerly flow. By afternoon...CAPE values surge toward 1000
j/kg...with only weak CIN or convective caps expected. All that`s
needed to tap into this instability and overcome this CIN is a
trigger. None of the models are forecasting a shortwave trough to
get things going during the afternoon...as much of the upper level
energy will remain far south of the forecast area. Thus the main
trigger will have to come from orographic ascent. It`s always
difficult to tell if this ascent will be strong enough to overcome
the CIN...but if it does...thunderstorms could develop rapidly.
Any updrafts could become sustained as 0-6 km shear values look
fairly impressive. Based on model soundings...we cannot rule out
an isolated severe or large thunderstorm....however confidence
would be much higher provided a shortwave would aid in the
breaking of the CIN.
Temperatures will begin the period near seasonal normals...however the
Monday pattern will lead to a significant warm up over the eastern
half of the forecast area...with 70s and even a lower 80 possible.
fx
Monday night through Friday...Overall agreement between models
exists in advertising the arrival of a deep upper level
trough/closed low early in the period...a residence time over or
near the forecast area during the lion`s share of the upcoming
work week...and then the slow departure near the end of the week.
Individual models differ with detailed placement of the main
trough axis/closed low center...but no matter which model verifies
confidence is increasing for a cooler than normal and unsettled
forecast through most of next week. While there are no easily
identifiable organized storm systems within this flow regime...the
presence of wrap-around moisture providing fuel for instability
associated with cool air aloft will create a chance of showers
just about anywhere in the forecast area each day through Thursday
at least...with densest concentrations of showers over the high
terrain surrounding the basin and the eastern half of the Columbia
Basin. By Friday model consensus suggests an exit of the upper
level trough...which may provide the best bet for an essentially
dry day...although southwest flow in advance of the next offshore
trough may lead to a few showers on the higher terrain even on this
day. Once again...without drilling too much into the details given
sub-synoptic model differences...there is fairly high confidence
of a showery...cool and unsettled extended period. /Fugazzi
&&
.AVIATION...
00Z TAFS: Afternoon heating will promote sct -shra and isold -tsra
through 3z across NE WA and N ID. Attention will then turn toward
a vigorous cold front crossing the Cascades arnd 06z...and
Spokane-CDA 10-12z. Expect increasing showers along and ahead of
the front with brief MVFR cigs possible east of Moses Lake under the
heaviest showers. We will also be monitoring mid level instability
spreading across SE WA / lower ID Panhandle ahead of the frontal
passage potentially leading to nocturnal thunderstorms mainly during
the 6-11z timeframe. At this time...Lewiston will have the best
chance for -tsra. Dry air will filter into the region on Sat
leading to breezy winds and rapidly improving conditions outside
orographic -shra for the ID Panhandle. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 54 70 47 67 48 69 / 60 60 10 10 20 60
Coeur d`Alene 53 69 46 65 49 72 / 60 70 10 10 30 60
Pullman 55 68 44 65 49 68 / 60 60 10 10 40 60
Lewiston 61 73 53 72 55 75 / 60 60 10 10 50 60
Colville 52 76 45 73 47 70 / 70 50 0 10 10 70
Sandpoint 53 68 42 65 44 71 / 60 80 10 20 20 70
Kellogg 52 66 44 64 47 73 / 60 90 10 30 40 60
Moses Lake 58 77 50 74 53 68 / 40 20 0 10 30 60
Wenatchee 57 75 54 72 55 65 / 30 10 0 0 20 50
Omak 53 76 47 72 47 67 / 50 10 0 10 10 60
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1053 PM CDT FRI JUN 1 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVING INTO SOUTHWEST LOWER MICHIGAN EARLY
THIS AFTERNOON. A SHORTWAVE ROTATING AROUND THIS UPPER LOW IS
GENERATING A BAND OF LIGHT RAIN THAT IS PIVOTING INTO DOOR COUNTY.
PARTLY TO MOSTLY CLOUDY CONDITIONS RESIDE ELSEWHERE WITH
TEMPERATURES MAINLY INTO THE LOW TO MID 60S. AS THE UPPER LOW
SLOWLY MOVES NORTH OVER THE NEXT 24 HOURS...SMALL PRECIP CHANCES ARE
THE MAIN FORECAST CONCERN.
TONIGHT...THE NAM BECOMES A SOUTHERN OUTLIER WITH THE TRACK OF THE
SURFACE LOW BY 12Z SATURDAY SO USED THE GFS AND ECMWF MOSTLY FOR
THIS FORECAST. NEARLY VERTICALLY STACKED LOW PRESSURE WILL SWING
NORTH OVER LOWER MICHIGAN TO FAR SOUTHERN ONTARIO BY SATURDAY
MORNING. SATELLITE/RADAR TRENDS SUPPORT KEEPING A CHANCE OF SHOWERS
OVER FAR NE WISCONSIN THIS EVENING...BUT LOW TO MID-LEVEL WINDS WILL
EVENTUALLY BACK AROUND TO THE NORTHWEST AND WILL BRING IN DRIER AIR
BELOW 500MB INTO CENTRAL AND NORTHEAST WISCONSIN. AS A RESULT...THE
COLUMN WILL QUICKLY DRY OUT OVER MOST LOCATIONS EXCEPT FOR MAYBE
DOOR COUNTY WHERE A CHANCE OF SHOWERS WILL REMAIN THROUGH THE
NIGHT. THE PRESSURE GRADIENT DOES TIGHTEN TONIGHT AND SHOULD STILL
HAVE A MID/HIGH DECK OVERHEAD...SO THINK LOWS WILL BE WARMER THAN
LAST NIGHT. WILL GO WITH LOWS MAINLY IN THE 40S.
SATURDAY...THE LOW PRESSURE SYSTEM WILL MOVE SLIGHTLY TO THE
NORTHEAST...WHICH MEANS THE DEEPEST MOISTURE WILL REMAIN OVER DOOR
COUNTY. ELSEWHERE...THE INFLUX OF DRIER AIR WILL LEAD TO A PARTLY
TO MOSTLY CLOUDY START TO THE DAY. WARMING LOW LEVEL TEMPERATURES
WILL LEAD TO STEEP LOW LEVEL LAPSE RATES DEVELOPING BY
MIDDAY...WHICH YIELD 100-200 J/KG OF ML CAPE THROUGH THE AFTERNOON.
SHOULD SEE A WIDESPREAD CU FIELD DEVELOP AS A RESULT. NOT SURE IF
THE CU WILL GROW LARGE ENOUGH FOR SHOWERS. MID-LEVEL HEIGHTS WILL
BE RISING THROUGH THE AFTERNOON...THOUGH MODELS ARE HINTING AT A
SURFACE TROUGH DROPPING SOUTH OVER NORTHEAST WISCONSIN THAT COULD
INTERACT WITH THE INSTABILITY TO GENERATE THOSE SHOWERS...AND
POSSIBLY A RUMBLE OF THUNDER. WILL REMOVE POPS OUTSIDE OF DOOR
COUNTY FOR THE MORNING...BUT WILL LEAVE THEM FOR THE AFTERNOON IN
CASE THAT SURFACE TROUGH DOES APPEAR. HIGHS IN THE UPPER 60S TO
LOWER 70S.
.LONG TERM...SATURDAY NIGHT THRU NEXT FRIDAY. TIMING BEST PRECIP
CHANCES AND TEMPS CONTINUE TO BE MAIN FORECAST CHALLENGES.
THE VERTICALLY STACKED SYSTEM RESPONSIBLE FOR THE COOL WEATHER
OVER THE AREA WILL CONTINUE TO SLOWLY PUSH AWAY FROM THE AREA ON
SATURDAY NIGHT...ALLOWING SOME DRIER AIR TO WORK IN...BRINGING AN
END TO ANY SHOWER ACTIVITY. OTHER THAN SOME LINGERING SLIGHT
CHANCE POPS ACROSS THE THE AREA IN THE EVENING...WILL CONTINUE
WITH A DRY FORECAST FOR THE OVERNIGHT HOURS. CLOUDS WILL DECREASE
THROUGH THE EVENING AS THE DRY AIR WORKS INTO THE AREA...ALLOWING
TEMPS TO DROP INTO THE 40S NORTH...AND LOW 50S SOUTH. WEAK
MID/UPPER RIDGING BUILDS ACROSS THE UPPER MIDWEST AND WESTERN
GREAT LAKES ON SUNDAY...BRINGING DRY WEATHER AND A RETURN TO ABOVE
NORMAL TEMPERATURES.
AS THE RIDGE FLATTENS OVER THE WESTERN GREAT LAKES...AND BUILDS
OVER THE NORTHERN PLAINS...ANOTHER PIECE OF SHORTWAVE ENERGY IS
FORECAST TO RIDE ON THE EASTERN SIDE OF THE RIDGE SUNDAY NIGHT.
ECMWF/GFS/NAM ALL SHOW THIS FEATURE...WHILE THE CANADIAN IS
STRONGER WITH THE RIDGE AND KEEPS THE SHORTWAVE ENERGY OVER
SOUTHERN CANADA. GFS HAS SLOWED DOWN WITH ITS TIMING...ALIGNING
BETTER WITH THE ECMWF. SOME MINOR TIMING/STRENGTH DIFFERENCES
STILL REMAIN...BUT HARD TO IGNORE THE MAJORITY OF GUIDANCE...SO
WILL CONTINUE WITH SHOWER/STORM CHANCES ON SUNDAY NIGHT AND INTO
MONDAY. INSTABILITY AND FORCING NOT OVERLY IMPRESSIVE...SO WILL
KEEP POPS IN THE 20-40 PERCENT RANGE...AND ONLY MENTION ISOLATED
THUNDER.
PLENTY OF QUESTIONS REMAIN FOR THE MID TO LATE WEEK PERIOD...AS A
VERY BLOCKY PATTERN SETS UP OVER THE CONUS. MODELS HANDLE JUST
HOW BLOCKY THE PATTERN WILL BE DIFFERENTLY...LEADING TO LOW
CONFIDENCE ON WHEN THE BEST CHANCE FOR SHOWER/STORMS WILL BE.
MODELS CONTINUE TO SHOW WEAK PIECES OF ENERGY ROTATING AROUND THE
UPPER LOW THE EASTERN SEABOARD...EACH OF WHICH WOULD BRING A
CHANCE OF SHOWERS TO THE AREA. GFS IS THE MOST AGGRESSIVE WITH A
POTENT SHORTWAVE DROPPING SOUTH INTO WI ON MONDAY NIGHT. OTHER
MODELS WEAKER AND SLOWER WITH THIS FEATURE. HARD TO RULE OUT
ISOLATED ACTIVITY DEVELOPING WITH DAYTIME HEATING DURING THE MID
TO LATE WEEK PERIOD...SO WILL CONTINUE WITH SLIGHT CHANCE POPS TO
COVER...AS CONFIDENCE NOT HIGH ENOUGH TO BUMP POPS HIGHER.
HIGH TEMPS A LITTLE TRICKY FOR NEXT WEEK...WITH RIDGING TRYING TO
BUILD INTO THE AREA...BUT PERSISTENT EAST WINDS NOT ALLOWING THE
REAL WARM AIR TO MAKE IT TO EASTERN WI. WILL CONTINUE USE A "MIDDLE
OF THE ROAD" APPROACH...WITH HIGHS GENERALLY IN THE 70S AWAY FROM
THE LAKE.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH SATURDAY EVENING.
DEEPER MOISTURE AND UPPER LEVEL DISTURBANCES ROTATING AROUND A
GREAT LAKES UPPER LOW WILL BRING SOME SHOWERS TO FAR NE WI...
ESPECIALLY DOOR COUNTY...THROUGH SATURDAY EVENING. FORECAST
SOUNDINGS INDICATE THAT MARGINAL LLWS IS POSSIBLE EARLY SATURDAY
MORNING...BUT APPEARS TO BE TOO BORDERLINE TO ADD TO THE 06Z TAFS.
WILL HAVE SOME INSTABILITY FOR SHOWER CHANCES SATURDAY AFTERNOON...
AND HAVE ADDED VCSH FOR AUW/CWA/GRB/ATW FROM MID-AFTERNOON
THROUGH EARLY EVENING. NW WINDS WILL ALSO TURN GUSTY BY LATE
SATURDAY MORNING...WITH GUSTS OVER 25 KTS POSSIBLE. THE WIND
SHOULD SUBSIDE BY EARLY SATURDAY EVENING.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
648 PM CDT FRI JUN 1 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SATURDAY.
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVING INTO SOUTHWEST LOWER MICHIGAN EARLY
THIS AFTERNOON. A SHORTWAVE ROTATING AROUND THIS UPPER LOW IS
GENERATING A BAND OF LIGHT RAIN THAT IS PIVOTING INTO DOOR COUNTY.
PARTLY TO MOSTLY CLOUDY CONDITIONS RESIDE ELSEWHERE WITH
TEMPERATURES MAINLY INTO THE LOW TO MID 60S. AS THE UPPER LOW
SLOWLY MOVES NORTH OVER THE NEXT 24 HOURS...SMALL PRECIP CHANCES ARE
THE MAIN FORECAST CONCERN.
TONIGHT...THE NAM BECOMES A SOUTHERN OUTLIER WITH THE TRACK OF THE
SURFACE LOW BY 12Z SATURDAY SO USED THE GFS AND ECMWF MOSTLY FOR
THIS FORECAST. NEARLY VERTICALLY STACKED LOW PRESSURE WILL SWING
NORTH OVER LOWER MICHIGAN TO FAR SOUTHERN ONTARIO BY SATURDAY
MORNING. SATELLITE/RADAR TRENDS SUPPORT KEEPING A CHANCE OF SHOWERS
OVER FAR NE WISCONSIN THIS EVENING...BUT LOW TO MID-LEVEL WINDS WILL
EVENTUALLY BACK AROUND TO THE NORTHWEST AND WILL BRING IN DRIER AIR
BELOW 500MB INTO CENTRAL AND NORTHEAST WISCONSIN. AS A RESULT...THE
COLUMN WILL QUICKLY DRY OUT OVER MOST LOCATIONS EXCEPT FOR MAYBE
DOOR COUNTY WHERE A CHANCE OF SHOWERS WILL REMAIN THROUGH THE
NIGHT. THE PRESSURE GRADIENT DOES TIGHTEN TONIGHT AND SHOULD STILL
HAVE A MID/HIGH DECK OVERHEAD...SO THINK LOWS WILL BE WARMER THAN
LAST NIGHT. WILL GO WITH LOWS MAINLY IN THE 40S.
SATURDAY...THE LOW PRESSURE SYSTEM WILL MOVE SLIGHTLY TO THE
NORTHEAST...WHICH MEANS THE DEEPEST MOISTURE WILL REMAIN OVER DOOR
COUNTY. ELSEWHERE...THE INFLUX OF DRIER AIR WILL LEAD TO A PARTLY
TO MOSTLY CLOUDY START TO THE DAY. WARMING LOW LEVEL TEMPERATURES
WILL LEAD TO STEEP LOW LEVEL LAPSE RATES DEVELOPING BY
MIDDAY...WHICH YIELD 100-200 J/KG OF ML CAPE THROUGH THE AFTERNOON.
SHOULD SEE A WIDESPREAD CU FIELD DEVELOP AS A RESULT. NOT SURE IF
THE CU WILL GROW LARGE ENOUGH FOR SHOWERS. MID-LEVEL HEIGHTS WILL
BE RISING THROUGH THE AFTERNOON...THOUGH MODELS ARE HINTING AT A
SURFACE TROUGH DROPPING SOUTH OVER NORTHEAST WISCONSIN THAT COULD
INTERACT WITH THE INSTABILITY TO GENERATE THOSE SHOWERS...AND
POSSIBLY A RUMBLE OF THUNDER. WILL REMOVE POPS OUTSIDE OF DOOR
COUNTY FOR THE MORNING...BUT WILL LEAVE THEM FOR THE AFTERNOON IN
CASE THAT SURFACE TROUGH DOES APPEAR. HIGHS IN THE UPPER 60S TO
LOWER 70S.
.LONG TERM...SATURDAY NIGHT THRU NEXT FRIDAY. TIMING BEST PRECIP
CHANCES AND TEMPS CONTINUE TO BE MAIN FORECAST CHALLENGES.
THE VERTICALLY STACKED SYSTEM RESPONSIBLE FOR THE COOL WEATHER
OVER THE AREA WILL CONTINUE TO SLOWLY PUSH AWAY FROM THE AREA ON
SATURDAY NIGHT...ALLOWING SOME DRIER AIR TO WORK IN...BRINGING AN
END TO ANY SHOWER ACTIVITY. OTHER THAN SOME LINGERING SLIGHT
CHANCE POPS ACROSS THE THE AREA IN THE EVENING...WILL CONTINUE
WITH A DRY FORECAST FOR THE OVERNIGHT HOURS. CLOUDS WILL DECREASE
THROUGH THE EVENING AS THE DRY AIR WORKS INTO THE AREA...ALLOWING
TEMPS TO DROP INTO THE 40S NORTH...AND LOW 50S SOUTH. WEAK
MID/UPPER RIDGING BUILDS ACROSS THE UPPER MIDWEST AND WESTERN
GREAT LAKES ON SUNDAY...BRINGING DRY WEATHER AND A RETURN TO ABOVE
NORMAL TEMPERATURES.
AS THE RIDGE FLATTENS OVER THE WESTERN GREAT LAKES...AND BUILDS
OVER THE NORTHERN PLAINS...ANOTHER PIECE OF SHORTWAVE ENERGY IS
FORECAST TO RIDE ON THE EASTERN SIDE OF THE RIDGE SUNDAY NIGHT.
ECMWF/GFS/NAM ALL SHOW THIS FEATURE...WHILE THE CANADIAN IS
STRONGER WITH THE RIDGE AND KEEPS THE SHORTWAVE ENERGY OVER
SOUTHERN CANADA. GFS HAS SLOWED DOWN WITH ITS TIMING...ALIGNING
BETTER WITH THE ECMWF. SOME MINOR TIMING/STRENGTH DIFFERENCES
STILL REMAIN...BUT HARD TO IGNORE THE MAJORITY OF GUIDANCE...SO
WILL CONTINUE WITH SHOWER/STORM CHANCES ON SUNDAY NIGHT AND INTO
MONDAY. INSTABILITY AND FORCING NOT OVERLY IMPRESSIVE...SO WILL
KEEP POPS IN THE 20-40 PERCENT RANGE...AND ONLY MENTION ISOLATED
THUNDER.
PLENTY OF QUESTIONS REMAIN FOR THE MID TO LATE WEEK PERIOD...AS A
VERY BLOCKY PATTERN SETS UP OVER THE CONUS. MODELS HANDLE JUST
HOW BLOCKY THE PATTERN WILL BE DIFFERENTLY...LEADING TO LOW
CONFIDENCE ON WHEN THE BEST CHANCE FOR SHOWER/STORMS WILL BE.
MODELS CONTINUE TO SHOW WEAK PIECES OF ENERGY ROTATING AROUND THE
UPPER LOW THE EASTERN SEABOARD...EACH OF WHICH WOULD BRING A
CHANCE OF SHOWERS TO THE AREA. GFS IS THE MOST AGGRESSIVE WITH A
POTENT SHORTWAVE DROPPING SOUTH INTO WI ON MONDAY NIGHT. OTHER
MODELS WEAKER AND SLOWER WITH THIS FEATURE. HARD TO RULE OUT
ISOLATED ACTIVITY DEVELOPING WITH DAYTIME HEATING DURING THE MID
TO LATE WEEK PERIOD...SO WILL CONTINUE WITH SLIGHT CHANCE POPS TO
COVER...AS CONFIDENCE NOT HIGH ENOUGH TO BUMP POPS HIGHER.
HIGH TEMPS A LITTLE TRICKY FOR NEXT WEEK...WITH RIDGING TRYING TO
BUILD INTO THE AREA...BUT PERSISTENT EAST WINDS NOT ALLOWING THE
REAL WARM AIR TO MAKE IT TO EASTERN WI. WILL CONTINUE USE A "MIDDLE
OF THE ROAD" APPROACH...WITH HIGHS GENERALLY IN THE 70S AWAY FROM
THE LAKE.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH SATURDAY. SCATTERED
SHOWERS THAT DEVELOPED ACROSS PARTS OF NC/C/NE WI ALONG A WEAK
SURFACE BOUNDARY...SHOULD QUICKLY DISSIPATE BY SUNSET. HAVE ADDED
VCSH IN THE RHI/AUW/CWA TAFS EARLY THIS EVG TO COVER THIS.
DEEPER MOISTURE AND UPPER LEVEL DISTURBANCES ROTATING AROUND A
GREAT LAKES UPPER LOW WILL ALSO BRING SOME SHOWERS TO FAR NE WI...
ESPECIALLY DOOR COUNTY. FORECAST SOUNDINGS INDICATE THAT THERE MAY
BE A BRIEF PERIOD OF MARGINAL LLWS EARLY SATURDAY MORNING...BUT
WILL TAKE ANOTHER LOOK AT THE LATEST DATA BEFORE DECIDING WHETHER
OR NOT TO ADD IT TO THE 06Z TAFS. WILL HAVE MORE INSTABILITY FOR
SHOWER CHANCES TOMORROW AFTERNOON THAN TODAY...AND HAVE ADDED VCSH
FOR AUW/CWA/GRB/ATW AFTER 20Z. NW WINDS WILL ALSO TURN GUSTY ON
SATURDAY MORNING...WITH GUSTS TO 25 TO 30 KTS POSSIBLE.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
608 PM CDT FRI JUN 1 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
247 PM CDT FRI JUN 1 2012
FORECAST CHALLENGES MAINLY CENTERED AROUND SHOWER/ISOLATED THUNDER
CHANCES THROUGH THE PERIOD.
CURRENT WATER VAPOR AND RAP 500MB ANALYSIS SHOW A CLOSED LOW OVER
LAKE MICHIGAN WHILE A WEAK MID-LEVEL TROUGH WAS ROTATING SOUTHEAST
THROUGH ND. COLD POOL ALOFT ASSOCIATED WITH THE LAKE MICHIGAN LOW
WAS PRODUCING STEEP TEMPERATURES LAPSE RATES AND EXTENSIVE CUMULUS
FIELD ACROSS THE FORECAST AREA. RADAR QUIET AT THIS POINT WITH NO
SIGNIFICANT ECHOES/SHOWERS INDICATED. MEANWHILE...FORCING ASSOCIATED
WITH THE WAVE UPSTREAM OVER ND WAS PRODUCING SCATTERED SHOWERS/ISOLD
THUNDER ACROSS ACROSS EASTERN ND INTO EASTERN NEB. OTHERWISE...
TEMPERATURES ACROSS THE FORECAST AREA THIS AFTERNOON WERE IN THE MID
60S TO AROUND 70 DEGREES.
01.12Z NCEP MODELS AND 01.09Z SREF SHOWING GOOD AGREEMENT WITH
HANDLING OF SYNOPTIC PATTERN THROUGH SUNDAY. GFS A BIT DEEPER WITH
THE MID-LEVEL WAVE ROTATING ACROSS ACROSS THE AREA MONDAY FOR BETTER
SATURATION/RAINFALL POTENTIAL. GENERALLY WENT WITH A CONSENSUS BLEND
AS A RESULT.
FOR TONIGHT...WILL BE WATCHING THE WAVE OVER ND ROTATE SOUTHEAST
WHILE DAMPENING OUT SOME. THE WAVE IS EXPECTED TO SCOOT SOUTHEAST
INTO IA BY 12Z. MOST OF THE FORCING...IE PV-ADVECTION/ISENTROPIC
LIFT AND MOISTURE TRANSPORT AND RESULTANT -SHRA CHANCES EXPECTED TO
BE TIED VERY CLOSE TO THE WAVE ITSELF AND JUST SOUTHWEST OF THE
AREA. HI-RES MESO MODELS ALSO SHOWS ACTIVITY REMAINING MAINLY
SOUTHWEST OF THE AREA. MAINTAINED JUST A SLIGHT -SHRA CHANCE
BASICALLY SOUTHWEST OF A LINE FROM AUSTIN MN TO OELWEIN IA AFTER 03Z
UNTIL 12Z. REST OF THE AREA/BASICALLY EAST OF THE MISSISSIPPI RIVER
SHOULD SEE CLEARING SKIES. THE CLEARING SKIES AND VERY LIGHT
NORTHWEST WINDS ARE EXPECTED TO PRODUCE FAIRLY CHILLY TEMPERATURES
OVERNIGHT...MAINLY IN THE FAVORED COLD SPOT AREAS SUCH AS
SPARTA/BLACK RIVER FALLS. WILL LIKELY SEE TEMPERATURES DIP INTO THE
UPPER 30S IN THOSE AREAS. ELSEWHERE...EXPECT TEMPERATURES MAINLY IN
THE 40S.
FOR SATURDAY...CLOSED LOW WILL DEEPEN SOME OVER LAKE HURON.
ASSOCIATED COLD POOL/CYCLONIC FLOW ALOFT WILL RESIDE OVER THE AREA
WITH 0-3KM MUCAPE AROUND 800J/KM AND MLCAPE AROUND 500J/KG. THIS
SHOULD BE SUFFICIENT ENOUGH FOR SHRA CHANCES ALONG WITH ISOLD
THUNDER. NAM SHOWING ABOUT 15-16 PVU/S ADVECTING SOUTHEAST ACROSS
AREAS NORTHEAST OF I-94 FOR PERHAPS A BETTER SHOT AT THUNDER
ACTIVITY. OTHERWISE...WITH EXTENSIVE CUMULUS AND ISOLD/SCT SHRA
ACTIVITY...TEMPERATURES ARE EXPECTED TO REMAIN SLIGHTLY BELOW NORMAL
IN THE UPPER 60S TO LOWER 70S. A FEW SHOWERS EXPECTED TO LINGER INTO
EARLY SATURDAY EVENING MAINLY NORTHEAST OF I-94. LOOK FOR CLEARING
SKIES THEN THROUGH THE REMAINDER OF THE OVERNIGHT HOURS AS SURFACE
HIGH PRESSURE DRIFTS OVER THE REGION WITH LOWS FALLING INTO THE
MIDDLE 40S TO LOWER 50S.
LATEST MODELS ARE TRENDING A BIT FASTER/STRONGER WITH A MID-LEVEL
TROUGH MOVING SOUTHEAST OUT OF THE NORTHERN PLAINS ON SUNDAY.
AFFECTS OF THIS WAVE WILL BE INCREASING MID-LEVEL CLOUDS THROUGH THE
AFTERNOON WITH A CHANCE OF SHRA/ISOLD THUNDER. THIS WILL BE MANLY
NORTHWEST OF A LINE FROM NEILLSVILLE AND ARCADIA WI...TO CHARLES
CITY IA WHERE NOSE OF 850-700MB MOISTURE TRANSPORT/ISENTROPIC LIFT
WILL BE DIRECTED. LOOK LIKE TEMPERATURES SHOULD BE RIGHT AROUND
NORMAL IN THE MID-UPPER 70S.
LOOK FOR THE MID-LEVEL TROUGH TO ROTATE OVER/ACROSS THE AREA SUNDAY
NIGHT INTO MONDAY FOR A GOOD CHANCE OF SHRA/ISOLD THUNDER. HIGHS
SUNDAY AND MONDAY ARE EXPECTED TO CONTINUE RIGHT AROUND NORMAL IN
THE MID 70S TO A FEW LOWER 80S.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
247 PM CDT FRI JUN 1 2012
01.12Z GFS/ECMWF APPEAR TO BE HAVING PROBLEMS RESOLVING WHERE
EXACTLY OMEGA BLOCK HIGH IS GOING TO SET UP THROUGH THE PERIOD. THE
GFS/ECMWF SEEM TO HAVE FLIP-FLOPPED WITH EACH OTHER/S SOLUTION.
EITHER WAY...APPEARS THE AREA WILL REMAIN JUST EAST OF THIS
RIDGE/OMEGA BLOCK AND WILL BE SUSCEPTIBLE TO CYCLONIC FLOW ALOFT
WITH EMBEDDED IMPULSES. THIS YIELDS SLIGHT CHANCE OF SHOWERS EACH
DAY. OTHERWISE...HIGH TEMPERATURES SHOULD REMAIN RIGHT AROUND NORMAL
LEVELS IN THE 70S.
&&
.AVIATION...TONIGHT AND SATURDAY
608 PM CDT FRI JUN 1 2012
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE PERIOD. MOST THE
CLOUDS CURRENTLY OVER THE AREA ARE EXPECTED TO DISSIPATE WITH THE
LOSS OF THE DAYTIME HEATING LEAVING BEHIND MOSTLY CLEAR SKIES FOR
THE OVERNIGHT HOURS. SOME SHOWERS CURRENTLY OVER THE EASTERN
DAKOTAS AND SOUTHWEST MINNESOTA THAT ARE MOVING SOUTH/SOUTHEAST.
THE 01.18Z NAM AND 01.20Z HRRR BOTH SHOW THESE SHOWERS HOLDING
TOGETHER AFTER SUNSET BUT REMAINING WELL TO THE WEST OF THE AREA
AND ONLY EXPECTING SOME HIGH LEVEL CLOUDS FROM THESE AT MOST. MORE
DIURNAL CUMULUS EXPECTED TO FORM LATE SATURDAY MORNING OR EARLY IN
THE AFTERNOON WITH CYCLONIC FLOW ALOFT AND STEEP LAPSE RATES.
COULD ONCE AGAIN BE SOME ISOLATED SHOWERS AROUND BUT CONFIDENCE
THAT ONCE OF THESE WOULD HIT A TAF SITE IS VERY LOW AND WILL LEAVE
THE FORECASTS DRY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CDT FRI JUN 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
304 PM CDT THU MAY 31 2012
.SHORT TERM...TONIGHT THROUGH SUNDAY
304 PM CDT THU MAY 31 2012
FORECAST CHALLENGES INCLUDE LINGERING SHOWERS INTO THIS
EVENING...THEN CLEARING AND FOG POTENTIAL OVERNIGHT/EARLY FRIDAY
MORNING. ANOTHER CHALLENGE WILL BE THE POTENTIAL FOR REDEVELOPMENT
OF ISOLATED SHOWERS FRIDAY.
CURRENT WATER VAPOR IMAGERY COMBINED WITH 500 MB RAP ANALYSIS SHOW
DEEP MID-LEVEL TROUGH ROTATING SOUTHEAST TROUGH WI/SOUTHERN WI. COLD
AIR ALOFT/LINGERING MID-LEVEL FRONTOGENESIS ASSOCIATED WITH THE
TROUGH WAS PRODUCING SCATTERED SHOWER ACTIVITY ACROSS PORTIONS OF
THE FORECAST AREA. OTHERWISE...CLOUD COVER WAS PRETTY EXTENSIVE
ACROSS THE AREA AND THIS WAS HOLDING TEMPERATURES DOWN IN THE MID/UPPER
50S WHICH IS SOME 20 DEGREES BELOW NORMAL.
31.12Z NCEP MODEL SUITE ALONG WITH THE 31.09Z SREF SHOWING GOOD
AGREEMENT WITH OVERALL SYNOPTIC SETUP THROUGH THE SHORT TERM.
FOR TONIGHT...WILL SEE THAT MID-LEVEL TROUGH MORPH INTO A CLOSED LOW
AND MOVE EAST TOWARD LAKE MICHIGAN THROUGH THE OVERNIGHT HOURS.
APPEARS A FEW DEFORMATION AREA -SHRA WILL LINGER ACROSS THE SOUTH
INTO THE EARLY EVENING HOURS...BUT THEN SHOULD DISSIPATE AROUND 8-9
PM. THE REST OF TONIGHT WILL SEE SLOWLY CLEARING SKIES FROM
NORTHWEST TO SOUTHEAST. CLEARING SKIES/LIGHT WINDS/FAIRLY MOIST
LOWER BOUNDARY LAYER WILL LEAD TO THE POTENTIAL FOR SOME FOG.
MITIGATING FACTOR TO WIDESPREAD FOG WILL BE LIGHT NORTHERLY
COMPONENT TO THE WIND WITH SPEEDS AROUND 10KT AT 500-1000AGL. KEPT
AREAS OF FOG LIMITED TO MISSISSIPPI/WISCONSIN RIVER VALLEYS WHERE
BETTER DECOUPLING OF THE WINDS WILL TAKE PLACE. OTHERWISE...LOOK FOR
OVERNIGHT LOWS ACROSS THE AREA IN THE UPPER 30S IN FAVORED
LOWER-LYING COLD AREAS...TO THE LOWER/MID 40S ELSEWHERE.
ON FRIDAY...THE CLOSED LOW WILL CONTINUE TO DEEPEN AND MOVE SLOWLY
EAST INTO LOWER MICHIGAN. CYCLONIC FLOW/COLD POOL ALOFT WILL RESIDE
OVER OUR AREA WITH STEEP 0-3KM TEMPERATURE LAPSE RATES IN THE
8.5-9C/KM RANGE. NAM ALSO SHOWING 0-3KM MUCAPE AROUND 300J/KG. THIS
SHOULD BE SUFFICIENT FOR EXTENSIVE CUMULUS/TOWERING CUMULUS FIELD
OVER THE FORECAST AREA ALONG WITH ISOLATED SHOWER ACTIVITY. LOOK FOR
HIGHS FRIDAY UNDER THE COLD POOL ALOFT TO TOP OFF IN THE 65-70
DEGREE RANGE. A FEW LINGERING -SHRA STILL POSSIBLE ALONG/NORTHEAST
OF I-94 EARLY FRIDAY EVENING. SCATTERED SHOWERS ALSO POSSIBLE
MAINLY ALONG AND WEST OF THE MISSISSIPPI RIVER FRIDAY NIGHT AS A
WEAK MID-LEVEL TROUGH DROPS SOUTHEAST FROM THE DAKOTAS INTO IA.
FOR SATURDAY...THE CLOSED LOW MOVES INTO EASTERN UPPER MI WITH COLD
CYCLONIC FLOW ALOFT LINGERING ACROSS OUR AREA. THE NAM SHOWS 0-3KM
MUCAPE INCREASING INTO THE 1000-1400J/KG RANGE WHILE 0-1KM ML CAPE
AROUND 500J/KG. THIS WILL LEAD TO ANOTHER DAY OF EXTENSIVE
CUMULUS/TOWERING CUMULUS FIELD ALONG WITH SCATTERED SHRA AND A FEW
THUNDERSTORMS. OTHERWISE...HIGHS SATURDAY ANTICIPATED TO TOP OFF
AGAIN IN THE 65-70 DEGREE RANGE. LOOK FOR THE CONVECTION/CLOUDS TO
DISSIPATED BY EARLY EVENING AS THE LOW/COLD POOL ALOFT MOVES FARTHER
EAST TOWARD LAKE HURON AND RIDGING BUILDS IN FROM THE NORTHERN
PLAINS.
WILL GO DRY ON SUNDAY AS MODELS ARE A BIT SLOWER WITH A MID-LEVEL
TROUGH TOPPING THE RIDGE OVER THE DAKOTAS/CENTRAL PLAINS. WILL
HOWEVER LIKELY SEE AN INCREASE IN MID-HIGH LEVEL CLOUDINESS IN
ADVANCE OF THIS FEATURE.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
304 PM CDT THU MAY 31 2012
31.12Z GFS/ECMWF SHOW A RATHER BLOCKY PATTERN SETTING UP THROUGH THE
PERIOD WITH TROUGHS RESIDING OVER WEST/EAST COASTS AND RIDGE OF HIGH
PRESSURE GETTING PINCHED OVER THE CENTRAL CONUS. SHRA/TS CHANCES
WILL BE SEEN SUNDAY NIGHT THROUGH MONDAY AS A WEAKENING MID-LEVEL
TROUGH TOPS THE RIDGE OVER THE DAKOTAS AND HEADS TOWARD THE UPPER
MISSISSIPPI RIVER VALLEY. FORCING NOT VERY IMPRESSIVE WITH THIS
FEATURE SO WILL CONTINUE WITH SMALLER-END CHANCES FOR NOW. NARROW
RIDGE OF HIGH PRESSURE LOOKS TO KEEP THE AREA DRY THROUGH THE
REMAINDER OF THE PERIOD. TEMPERATURES EXPECTED TO BE MORE SEASONABLE
MONDAY THROUGH THURSDAY AS WELL WITH HIGHS IN THE MID 70S TO AROUND
80.
&&
.AVIATION...THROUGH 18Z FRIDAY
1155 AM CDT THU MAY 31 2012
CIGS ASSOCIATED WITH AN AREA OF LOW PRESSURE WILL EXIT THE AREA THIS
EVENING AS AN AREA OF HIGH PRESSURE BUILDS IN FROM THE PLAINS.
SCT/ISOLD -SHRA STILL POSSIBLE AT KRST/KLSE THROUGH 21Z OR SO. WILL
LEAVE OUT OF TAFS FOR NOW AS CONFIDENCE IS HIGHER FOR PCPN CHANCES
TO THE SOUTH. WILL AMEND IF NECESSARY.
THE HIGH WILL BRING LIGHTER NEAR SFC WINDS...CLEARING SKIES...AND
DRIER AIR. HOWEVER...RECENT RAINS WILL LEAVE A MOISTURE SOURCE AT
THE SFC...AND SEE A THREAT FOR VALLEY FOG EARLY FRI MORNING. NAM12
BUFKIT SOUNDINGS SUGGESTS T/TD SPREAD DECREASES RAPIDLY AT KLSE THIS
EVENING...BUT THE RAP KEEPS A FEW DEGREE SPREAD THROUGH THE NIGHT AS
DOES THE GFS. COULD BE ADVECTING IN DRIER SFC AIR FROM THE
NORTH...WHICH WOULD KEEP FOG FROM DEVELOPING. CONFIDENCE SHAKY ON
HOW MUCH OR IF FOG WILL FORM. WILL GO WITH BCFG FOR NOW. TRENDS WILL
BE MONITORED THROUGH THE EVENING.
GOOD LOW LEVEL LAPSE RATES OF AROUND 9 C/KM IN THE 1000:850 MB LAYER
AND SOME RESIDUAL LOW LEVEL MOISTURE SHOULD LEAD TO SOME LATE
MORNING/AFTERNOON CU. NOT SURE THERE IS ENOUGH MOISTURE/INSTABILITY
TO PRODUCE -SHRA. SOMETHING TO WATCH FOR TOMORROW...BUT WILL LEAVE
OUT OF THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
304 PM CDT THU MAY 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1155 AM CDT THU MAY 31 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
322 AM CDT THU MAY 31 2012
MAIN FORECAST CONCERNS ARE ON RAIN SHOWERS TODAY MAINLY ALONG AND
SOUTH OF INTERSTATE 90. FOCUS THEN TURNS TO FOG POTENTIAL TONIGHT
ALONG THE MISSISSIPPI AND WISCONSIN RIVER VALLEYS.
AS OF 3 AM THIS MORNING...WATER VAPOR IMAGERY SHOWED AN UPPER LEVEL
TROUGH MOVING INTO UPPER AND MIDDLE MISSISSIPPI RIVER VALLEY. RAIN
WAS FALLING THIS MORNING ACROSS MUCH OF SOUTHEAST
MINNESOTA...NORTHEAST IOWA INTO PORTIONS OF SOUTHWEST AND CENTRAL
WISCONSIN.
THE TROUGH WILL GRADUALLY DRIFT EAST ACROSS THE FORECAST AREA TODAY
AND IS EXPECTED TO CLOSE INTO AN UPPER LOW ALONG THE
WISCONSIN/ILLINOIS BORDER LATE THIS AFTERNOON. PLAN ON CLOUDY SKIES
ACROSS THE AREA TODAY WITH RAIN ALONG AND SOUTH OF INTERSTATE 90
THIS MORNING. THE RAIN BAND IS SUPPORTED BY A BAND OF FRONTOGENESIS
IN THE THE 700-500 MB LAYER. THIS BAND WEAKENS THROUGH 15Z THIS
MORNING...SO SHOULD SEE STRATIFORM RAIN SWITCH OVER TO RAIN SHOWERS
LATE THIS MORNING INTO THIS AFTERNOON. THE MAIN FORCING FOR THE
RAIN SHOWERS THIS AFTERNOON WILL BE DRIVEN BY WEAK OMEGA IN THE
900-700 MB LAYER AND COOLER AIR ALOFT PRODUCING STEEP LAPSE RATES.
SHOULD SEE THE SHOWERS BECOME MORE SCATTERED EARLY THIS AFTERNOON
THROUGH THE LATE AFTERNOON HOURS. PLAN ON HIGHS TODAY RANGING FROM
THE LOWER 60S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER 50S OVER
NORTHEAST IOWA...RATHER CHILLY FOR THIS TIME OF YEAR. NORMAL HIGHS
FOR THIS TIME OF YEAR ARE IN THE LOWER TO MIDDLE 70S.
THE UPPER LOW WILL SHIFT EAST OF THE FORECAST AREA TONIGHT AS
SURFACE HIGH PRESSURE EDGES INTO THE AREA FROM THE NORTHERN PLAINS.
WINDS WILL BECOME LIGHT TONIGHT AND CLOUDS ARE EXPECTED TO DECREASE
THROUGH THE OVERNIGHT HOURS. THIS LEADS TO FOG CONCERNS TONIGHT WITH
THE PRECIPITATION AND CLOUD COVER ACROSS THE REGION TODAY. THE MAIN
FOG CONCERNS WILL BE ALONG THE RIVER VALLEYS. FORECAST SOUNDINGS ARE
SHOWING LIGHT WINDS FROM THE SURFACE THROUGH AROUND 2 KFT...WITH
TEMPERATURE AND DEWPOINT SPREADS RANGING FROM 0-2 DEGREES. LOOKS
LIKE A DECENT SET UP FOR VALLEY FOG IF SKIES CLEAR. WILL INCLUDE
AREAS OF FOG ALONG MISSISSIPPI AND WISCONSIN RIVER VALLEYS FROM
MIDNIGHT TONIGHT THROUGH 8 AM FRIDAY MORNING. IF THE FOG DEVELOPS
PLAN ON VISIBILITIES REDUCED TO AROUND 1/4 MILE. LOOK FOR LOWS
TONIGHT TO FALL INTO THE LOWER 40S.
SURFACE HIGH PRESSURE WILL BE IN CONTROL ON FRIDAY AND SHOULD
PROVIDE DRY WEATHER ACROSS THE FORECAST AREA AS THE UPPER LOW DRIFTS
EAST OVER LOWER MICHIGAN. FORECAST SOUNDINGS SHOW THE POTENTIAL FOR
SOME HIGH BASED CUMULUS CLOUDS LATE FRIDAY MORNING INTO FRIDAY
AFTERNOON. PLAN ON MOSTLY SUNNY SKIES EARLY IN THE DAY ON
FRIDAY...BECOMING PARTLY SUNNY IN THE AFTERNOON. PLAN ON HIGH
TEMPERATURES RANGING FROM THE MIDDLE TO UPPER 60S. A SHORTWAVE
TROUGH IN NORTHWEST FLOW ALOFT WILL MOVE ACROSS THE EASTERN DAKOTAS
LATE FRIDAY AFTERNOON AND PUSH EAST APPROACHING THE UPPER
MISSISSIPPI RIVER VALLEY LATE FRIDAY NIGHT INTO SATURDAY. HIGH
CLOUDS WILL START TO SPILL INTO THE REGION AHEAD OF THIS FEATURE
LATE FRIDAY AFTERNOON INTO FRIDAY NIGHT. A FEW SHOWERS COULD MOVING
INTO PORTIONS OF SOUTHEAST MINNESOTA INTO NORTHEAST IOWA FRIDAY
NIGHT AS THE SHORTWAVE PUSHES INTO CENTRAL MINNESOTA. WINDS WILL
SWITCH TO THE WEST AS THIS WAVE DRAWS CLOSER...USHERING IN WARMER
AIR. PLAN ON LOWS FRIDAY NIGHT RANGING FROM THE MID 40S ACROSS NORTH
CENTRAL WISCONSIN TO THE UPPER 40S TO LOWER 50S OVER SOUTHEAST
MINNESOTA INTO NORTHEAST IOWA.
THE UPPER LEVEL LOW WILL FINALLY LIFT NORTH ACROSS WESTERN LAKE
HURON BY EARLY SATURDAY MORNING. THE SHORTWAVE PUSHES INTO THE UPPER
MISSISSIPPI RIVER VALLY DURING THE DAY ON SATURDAY BUT BECOMES
RATHER WASHED OUT AS IT MOVES INTO THE TROUGH ON THE BACK EDGE OF
THE UPPER LOW. THE NAM AND GFS TRY TO GENERATE CONVECTION ACROSS THE
FORECAST AREA DURING THE DAY ON SATURDAY WITH SURFACE BASED CAPE
VALUES INCREASING INTO THE 500-900 J/KG RANGE. THE GEM AND ECMWF
ARE DRY BUT HAVE SOME REFLECTION OF A WEAK SURFACE TROUGH IN THE
SURFACE PRESSURE FIELDS. COULD SEE ISOLATED SHOWERS AND
THUNDERSTORMS DEVELOP ON SATURDAY AS THIS TROUGH MOVES THROUGH...BUT
CONFIDENCE LOW THAT THIS WILL OCCUR. WILL HAVE TO KEEP A CLOSE WATCH
ON THIS THE NEXT FEW MODEL RUNS. WILL MAINTAIN SLIGHT CHANCES FOR
PRECIPITATION ON SATURDAY BUT WILL ADD THUNDER MENTION. IF
PRECIPITATION DEVELOPS IT WILL LIKELY BE SURFACE BASED AND WILL TAP
INTO SOME WEAK CAPE LEADING TO A FEW THUNDERSTORMS. IF THE STORMS
DEVELOP THEY WILL BE BATTLING WEAK SHEAR AND SUBSIDENCE IN THE
800-600 MB LAYER...SO WOULD EXPECT ANYTHING ORGANIZED. UPPER LEVEL
RIDGING IS EXPECTED TO PUSH INTO THE FORECAST AREA FROM THE NORTHERN
PLAINS LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT. THIS SHOULD
PROVIDE QUIET WEATHER SATURDAY EVENING. CONVECTION LOOKS TO ERUPT
OVER THE DAKOTAS SATURDAY NIGHT INTO SUNDAY AS A SHORTWAVE MOVES
THROUGH THE UPPER RIDGE EXPECTED TO DEVELOP ACROSS THE
CENTRAL/NORTHERN PLAINS. WILL HAVE TO KEEP A WATCH ON THIS ACTIVITY
LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING. 850 MB MOISTURE
TRANSPORT LOOKS TO STAY WELL WEST OF THE FORECAST AREA UNTIL EARLY
SUNDAY MORNING...SO SATURDAY NIGHT SHOULD BE DRY. PLAN ON HIGHS ON
SATURDAY CLIMBING INTO THE 70S WITH OVERNIGHT LOWS IN THE 50S.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
322 AM CDT THU MAY 31 2012
31.00 MEDIUM RANGE MODELS IN REASONABLE AGREEMENT ON SUNDAY SHOWING
A SHORTWAVE TROUGH MOVING ACROSS THE EASTERN DAKOTAS AND HEADING
SOUTHEAST INTO THE UPPER MISSISSIPPI RIVER VALLEY LATE SUNDAY
AFTERNOON INTO SUNDAY EVENING. LOOK FOR SHOWERS AND THUNDERSTORMS TO
SPREAD INTO THE AREA SUNDAY AFTERNOON INTO SUNDAY NIGHT AS THE
TROUGH MOVES ACROSS THE AREA. 0-3KM MUCAPE VALUES ARE EXPECTED TO
INCREASE INTO THE 1000-2500 J/KG RANGE...HIGHEST VALUES WEST OF THE
MISSISSIPPI RIVER...BY LATE SUNDAY EVENING. 0-6 KM SHEAR IS EXPECTED
TO BE AROUND 40 KTS...BUT THE STORMS WILL PROBABLY BE ELEVATED.
OVERALL EFFECTIVE SHEAR LOOKS LIMITED BUT WILL HAVE TO KEEP A CLOSE
WATCH ON THIS WITH THE NEXT FEW MODEL RUNS. HIGHS ON SUNDAY WILL
RANGE FROM THE MID 70S ACROSS NORTH CENTRAL WISCONSIN TO THE UPPER
70S ACROSS NORTHEAST IOWA. SHOWER AND THUNDERSTORM CHANCES WILL
CONTINUE INTO MONDAY BEFORE AN UPPER RIDGE BUILDS ACROSS THE AREA.
THE GFS AND ECMWF SHOW THE RIDGE HOLDING STRONG ACROSS THE AREA
MONDAY NIGHT INTO WEDNESDAY PROVIDING DRY AND QUIET WEATHER. THE
RIDGE LOOKS TO BREAK DOWN LATE WEDNESDAY INTO THURSDAY. PLAN ON
HIGHS IN THE 70S TO LOWER 80S MONDAY THROUGH TUESDAY. SLIGHTLY
COOLER TEMPERATURES ON POSSIBLE ON WEDNESDAY AS SURFACE HIGH
PRESSURE ATTEMPTS TO BUILD IN FROM THE NORTHEAST.
&&
.AVIATION...
1155 AM CDT THU MAY 31 2012
CIGS ASSOCIATED WITH AN AREA OF LOW PRESSURE WILL EXIT THE AREA THIS
EVENING AS AN AREA OF HIGH PRESSURE BUILDS IN FROM THE PLAINS.
SCT/ISOLD -SHRA STILL POSSIBLE AT KRST/KLSE THROUGH 21Z OR SO. WILL
LEAVE OUT OF TAFS FOR NOW AS CONFIDENCE IS HIGHER FOR PCPN CHANCES
TO THE SOUTH. WILL AMEND IF NECESSARY.
THE HIGH WILL BRING LIGHTER NEAR SFC WINDS...CLEARING SKIES...AND
DRIER AIR. HOWEVER...RECENT RAINS WILL LEAVE A MOISTURE SOURCE AT
THE SFC...AND SEE A THREAT FOR VALLEY FOG EARLY FRI MORNING. NAM12
BUFKIT SOUNDINGS SUGGESTS T/TD SPREAD DECREASES RAPIDLY AT KLSE THIS
EVENING...BUT THE RAP KEEPS A FEW DEGREE SPREAD THROUGH THE NIGHT AS
DOES THE GFS. COULD BE ADVECTING IN DRIER SFC AIR FROM THE
NORTH...WHICH WOULD KEEP FOG FROM DEVELOPING. CONFIDENCE SHAKY ON
HOW MUCH OR IF FOG WILL FORM. WILL GO WITH BCFG FOR NOW. TRENDS WILL
BE MONITORED THROUGH THE EVENING.
GOOD LOW LEVEL LAPSE RATES OF AROUND 9 C/KM IN THE 1000:850 MB LAYER
AND SOME RESIDUAL LOW LEVEL MOISTURE SHOULD LEAD TO SOME LATE
MORNING/AFTERNOON CU. NOT SURE THERE IS ENOUGH MOISTURE/INSTABILITY
TO PRODUCE -SHRA. SOMETHING TO WATCH FOR TOMORROW...BUT WILL LEAVE
OUT OF THE FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
322 AM CDT THU MAY 31 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1114 PM MDT FRI JUN 1 2012
.AVIATION...
MAIN CONCERN FOR NEXT 24 H IS THE POTENTIAL FOR TS AT THE TAF
SITES SAT AFTERNOON AND EVE. BEST CHANCE FOR STORMS WILL BE IN THE
19-24Z TIME FRAME AS STORMS DEVELOP OVR THE MTS AND BEGIN MOVING
OVR THE PLAINS. STORM MOVEMENT WILL GENERALLY BE TO THE E-NE AT
AROUND 20-30 KTS. A FEW STORMS COULD PRODUCE SOME HAIL UP TO 1
INCH DIAMETER...AND LOCAL WIND GUSTS TO 50 KTS. SVR STORMS WITH
LARGER HAIL WILL BE MORE LIKELY FROM KLHX EWD DURING THE LATE
AFTERNOON AND EARLY EVE. ROSE
&&
.PREV DISCUSSION... /ISSUED 237 PM MDT FRI JUN 1 2012/
SHORT TERM...
(TONIGHT AND TOMORROW)
..SEVERE WEATHER LIKELY TOMORROW...
CURRENTLY...
A COOL FRONT HAS GONE THROUGH THE REGION. THIS BOUNDARY WAS JUST
SOUTH OF THE CWA AND WAS MOVING SLOWLY SOUTH. WINDS NORTH OF THE
BOUNDARY WERE ALREADY TURNING UPSLOPE WITH DEWPOINTS IN THE 40S.
THIS AFTERNOON AND EVENING...
AT THIS TIME...BEST CHANCE FOR STRONGER CONVECTION IS JUST SOUTH OF
THE CWA. THERE WILL STILL BE A CHANCE OF A STRONG STORM ACROSS FAR
SOUTHERN LAS ANIMAS COUNTY LATER TODAY (AS SHOWN BY LATEST
HRRR)...BUT THIS CONVECTION WILL QUICKLY MOVE SOUTH INTO NEW MEXICO.
AS FOR THE REST OF THE REGION...SIMULATIONS HAVE BACKED OFF A BIT ON
CONVECTION ALONG THE EAST FACING SLOPES OF THE S MTNS FOR THIS
AFTERNOON AND EVENING. HRRR IS RATHER DRY BUT THIS MAY BE A BIT
PESSIMISTIC AS I BELIEVE WE WILL SEE A FEW TSRA DEVELOP AND MOVE OFF
THE MTNS LATE THIS AFTERNOON AND EARLY EVENING. WHAT I HAVE DONE IS
KEPT POPS IN THE FCST...BUT HAVE DECREASED ALL OF VALUES INTO THE
ISOLATED CATEGORY.
LATER TONIGHT...
MOISTURE IS FCST TO INCREASE TONIGHT OVER THE PLAINS AS FLOW JUST
OFF THE SFC BECOMES SOUTHEASTERLY. THIS IS FCST TO BRING 45-50F
DEPOTS INTO A GOOD PART OF THE PLAINS BY SUNRISE TOMORROW. SOME LOW
CLOUDS WILL BE POSSIBLE ACROSS THE FAR SE PLAINS.
TOMORROW...
A CLASSIC "DAY 2" SEVERE WEATHER SETUP IS LIKELY TOMORROW. ALL
MODELS SHOW BETWEEN 2000 AND 3000 J/KG OF CAPE IMPINGING INTO FAR SE
CO BY 21Z TOMORROW. WINDS ALOFT ARE NOT ALL THAT STRONG BUT
SUFFICIENT DEEP SHEAR (AND PLENTY OF INSTABILITY) ALONG WITH 8 TO
9C/KM LAPSE RATES WILL BE IN PLACE OVER THE REGION. ALL MODELS ARE
PRINTING OUT CONVECTIVE QPF AND I HAVE NO REASON NOT TO BELIEVE THIS
OUTPUT. GIVEN THIS...WE WILL LIKELY SEE SOME ROTATING CONVECTION
TOMORROW. ALTHOUGH ALL OF THE PLAINS MAY SEE SVR WX TOMORROW...IT
APPEARS THE GREATEST POTENTIAL FOR SEVERE WEATHER WILL BE EAST AND
SOUTH OF A LINE FROM EADS...TO LAS ANIMAS TO KIM...AS THE STRONGEST
WINDS ALOFT AND BEST CAPE WILL BE IN THIS REGION. SPC DAY2 HAS THIS
AREA OUTLOOKED. THE MAIN THREATS WILL BE HAIL AND WIND...ALTHOUGH A
TORNADO CANNOT BE RULED OUT...ESPECIALLY OVER BACA COUNTY. GIVEN THE
W-NW FLOW ALOFT...ROTATING STORMS TOMORROW WILL MOVE SOUTHEAST TO
SOUTH-SOUTHEAST.
LONG TERM...
(SATURDAY NIGHT THROUGH FRIDAY)
SATURDAY NIGHT...MODELS CONTINUE TO AGREE ON THUNDERSTORMS MOVING INTO
THE I-25 CORRIDOR AND EASTERN PLAINS SATURDAY NIGHT IN RESPONSE TO A
SHORTWAVE PASSING THROUGH NORTHERN COLORADO AND SOUTHEASTERLY FLOW
OVER THE EASTERN PLAINS. LATEST RUNS OF THE NAM/GFS/SREF ALL SHOW
0-6 KM BULK SHEARS OF 35-40 KTS...SBCAPE VALUES OF 1000-1500
J/KG...AND DEWPOINTS IN THE LOWER TO MID 50`S AT 00Z SUNDAY OVER THE
EASTERN PLAINS. THE GFS SHOWS THE MOST INSTABILITY WITH SBCAPE
VALUES OF OVER 2000 J/KG OVER THE EXTREME SOUTHEAST PLAINS...BUT
FEEL A MODEL CONSENSUS IS STILL THE APPROPRIATE SOLUTION IN THIS
CASE. SOME THUNDERSTORMS MAY BE SEVERE...ESPECIALLY CLOSE TO THE
KANSAS BORDER WHERE INSTABILITY WILL BE GREATEST.
SUNDAY-SUNDAY NIGHT...GFS/NAM CONTINUE TO SHOW WEAK WESTERLY FLOW
ALOFT ACROSS THE REGION AS AN UPPER LEVEL RIDGE BUILDS ACROSS THE
REGION AHEAD OF AN UPPER TROUGH MOVING ONSHORE ACROSS THE WEST
COAST. BOTH MODELS SHOW CONVECTION FORMING OVER THE HIGHER TERRAIN
SUNDAY AFTERNOON. AROUND 00Z MONDAY...THE NAM SHOWS CONVECTION
FIRING ACROSS THE EASTERN PLAINS WHERE DEWPOINTS ARE FORECAST TO BE
IN THE MID 50S AND SBCAPES OVER 1500 J/KG. THE GFS...ON THE OTHER
HAND...SHOWS DEWPOINTS CLOSER TO 50...HALF AS MUCH CAPE...AND NO QPF
OVER THE EASTERN PLAINS. I FEEL THE NAM IS OVERDONE IN THIS
CASE...BUT STILL FEEL THUNDERSTORM DEVELOPMENT IS POSSIBLE GIVEN THE
RESIDUAL SURFACE MOISTURE AND TEMPERATURES IN THE LOW TO MID 90S. POPS
OVER THE HIGHER TERRAIN AND EASTERN PLAINS WERE RAISED IN THESE
AREAS.
MONDAY-FRIDAY...THE RIDGE AXIS WILL MOVE EAST OF THE COLORADO BY
TUESDAY AFTERNOON. MODELS INDICATE HIGH BASED/MOUNTAIN THUNDERSTORMS
WILL BE POSSIBLE BOTH MONDAY AND TUESDAY NIGHT BUT WEAK STEERING
FLOW SHOULD KEEP THEM MOSTLY OVER THE HIGHER TERRAIN. FAIRLY WEAK
SOUTHWESTERLY FLOW WILL THEN MOVE OVER THE REGION IN RESPONSE TO A
PACIFIC TROUGH DIGGING INTO THE NORTHWEST. MODELS DISAGREE WITH THE
PLACEMENT AND STRENGTH OF THE TROUGH. THE EC DIGS THE TROUGH DEEPER
INTO UTAH BY WEDNESDAY NIGHT AND THURSDAY. THE GFS IS FARTHER
NORTHWEST AND WEAKER WITH THE TROUGH DURING THAT TIME PERIOD.
THURSDAY AND FRIDAY THE FORECAST AREA WILL REMAIN UNDER WEAK
SOUTHWESTERLY FLOW AS THE AFOREMENTIONED TROUGH BEGINS TO LIFT INTO
WESTERN CANADA. TEMPERATURES LOOK AS IF THEY WILL REMAIN ABOVE
AVERAGE DURING THE ENTIRE EXTENDED PERIOD ACROSS THE FORECAST AREA.
-PJC
AVIATION...
MAIN CONCERN WILL BE TOMORROW AFTERNOON AS STRONGER CONVECTION WILL
BE POSSIBLE DURING THE EARLY TO MID AFTERNOON TIME PERIODS AT KCOS
AND KPUB. ATTM...PLAN TO MENTION VCTS IN THE TAFS AT THESE TWO SITES
AND LET LATER AVIATION FCSTS FINE TUNE THE THUNDER THREAT. THERE
WILL ALSO BE A VERY SLIGHT CHANCE OF SOME THUNDER AT KCOS AND KPUB
LATER THIS AFTERNOON...BUT THREAT TOO LOW TO EXPLICITLY MENTION IN
TAF (IF RADAR TRENDS CHANGE THIS AFTERNOON...THEN TAFS FCST WILL BE
ADJUSTED ACCORDINGLY). OTHERWISE...VFR CONDITIONS ARE EXPECTED AT
KCOS...KPUB AND KALS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
44/31
AREA FORECAST DISCUSSION
NWS MIAMI FL
126 AM EDT SAT JUN 2 2012
.AVIATION...
SCATTERED SHOWERS CONTINUE ACROSS THE GULF AND INTO COLLIER COUNTY
EARLY THIS MORNING AHEAD OF AN UPPER TROUGH MOVING ACROSS THE
EASTERN GULF. EXPECT SHOWERS TO CONTINUE NEAR KAPF AND PUSH
TOWARDS THE EASTERN TAF SITES OVER THE NEXT FEW HOURS. THE UPPER
TROUGH WILL CONTINUE TO PUSH EAST THROUGH THE DAY TODAY...PUSHING
THE DEEPER MOISTURE TO THE SOUTH AND EAST AS WELL. SO THE BEST
CHANCE FOR TSRA THIS AFTERNOON WILL BE MAINLY ALONG THE EAST COAST
SOUTH OF KFXE. IF THERE IS ENOUGH DAYTIME HEATING...A SEA BREEZE
MAY TRY AND DEVELOP ALONG THE EAST COAST THIS AFTERNOON.
HOWEVER...WITH THE WESTERLY WINDS ALOFT...THE SURFACE WINDS MAY
ONLY SHIFT TO THE SOUTH OR SOUTH SOUTHWEST THIS AFTERNOON.
MOISTURE WILL CONTINUE TO GET PUSHED OUT OF THE REGION...AND
MAINLY DRY AND VFR CONDITIONS ARE EXPECTED OVERNIGHT SATURDAY
NIGHT.
&&
.PREV DISCUSSION... /ISSUED 756 PM EDT FRI JUN 1 2012/
UPDATE...SOME MAJOR ADJUSTMENTS PLANNED FOR THE EVENING UPDATES
BASED ON CURRENT TRENDS. MID LEVEL TROUGH THAT WAS DIGGING INTO
THE SOUTHEAST STATES AND HELPING TO LIFT DEEP TROPICAL MOISTURE
NORTHWARD IS EVIDENT ON WATER VAPOR MOVING INTO THE NORTHEAST GULF
OF MEXICO WHICH IN TURN IS AIDING IN SHIFTING THE BULK OF THE
CONVECTION EAST AND SOUTH OF THE PENINSULA. IN ADDITION, THIS IS
COMING IN LINE WITH THE LOSS OF DIURNAL HEATING OVER THE NEXT HOUR
AND FOR THESE REASONS IT APPEARS THE RISK OF FLOODING RAINS HAS
BEEN SUBSTANTIALLY REDUCED. THE HRRR WHICH HAS ACTUALLY BEEN OVER
ZEALOUS WITH THE ACTIVITY TODAY FORECASTS THE CONVECTION TO WEAKEN
THROUGH THE EVENING WHICH SEEMS REASONABLE GIVEN THE ABOVE
DISCUSSION. SO FOR ALL OF THESE REASONS, PLAN TO LOWER POPS TO
ONLY SCT LEVELS FOR THE NIGHTTIME HOURS AND CANCEL THE FFA FOR ALL
OF S FL.
KOB
PREV DISCUSSION... /ISSUED 626 PM EDT FRI JUN 1 2012/
AVIATION...TSRA MOVG OFSHR ATTM AND VCSH THRU 02Z WITH PSBL
REDVLPMNT TOWARD 12Z WITH VCTS AFT 16Z. OTRW...VFR E COAST FOR THE
MOST PART. SFC WNDS BCMG SW GENERALLY LESS THAN 10 KTS AND
PERSISTING. ATTM GUIDANCE INDICATES NO E COAST SEA BRZE SATURDAY.
AT KAPF....VCSH OVRNITE INTO SATURDAY AND PSBL MVFR CIGS BUT NOT
IN TAFS ATTM. SFC WNDS SW 10 KTS OR LESS.
PREV DISCUSSION... /ISSUED 223 PM EDT FRI JUN 1 2012/
SHORT TERM (TONIGHT-SUNDAY NIGHT)...
LATEST WATER VAPOR IMAGERY SHOWED THE UPPER TROUGH AXIS EXTENDING
SOUTH ACROSS THE REGION AND THE EASTERN GULF WITH A FEW LEAD
SHORTWAVES WITHIN THE SUB-TROPICAL JET LIFTING NE ACROSS THE STATE
AHEAD OF IT. UPPER HEIGHT FALLS COMBINED WITH A WEAK SURFACE TROUGH
AND PRECIPITABLE WATER VALUES IN THE 2 TO 2.5 INCH RANGE HAS
GENERATED A LARGE AREA OF DEEP MOIST CONVECTION AROUND AND JUST WEST
OF THE KEYS EARLIER THIS AFTERNOON. EXPECT THIS ACTIVITY TO CONTINUE
TO SPREAD EAST AND NORTHEAST ACROSS THE LOCAL AREA THROUGH THE
AFTERNOON AND EVENING PERIODS AS THE UPPER TROUGH AND COLD FRONT
APPROACH THE AREA FROM THE WEST AND NORTHWEST. THE FLOOD WATCH
REMAINS IN EFFECT INTO TONIGHT AND MAY NEED TO BE EXTENDED INTO
SATURDAY MORNING DEPENDING ON THE EVOLUTION OF THIS SYSTEM AND WHERE
THE BULK OF THE CONVECTION BECOMES CONCENTRATED. IN ADDITION TO THE
RAINFALL CONCERNS THROUGH TONIGHT...THE LATEST VISIBLE SATELLITE
IMAGERY WAS INDICATING A FEW BREAKS IN THE COVERAGE OVER THE
INTERIOR PORTIONS OF THE AREA...WHICH MAY ALLOW FOR SOME
DESTABILIZATION THROUGH THE AFTERNOON PERIOD. IF SO, A FEW STRONG
STORMS DEVELOPING CANNOT BE RULED OUT WITH THE MAIN CONCERN BEING
DAMAGING STRAIGHT LINE WIND GUSTS.
DESPITE SOME MINOR TIMING DIFFERENCES THAT WERE NOTED FROM EARLIER
MODEL SOLUTIONS IN PREVIOUS DISCUSSIONS...THE LATEST MODEL CYCLE
APPEARS TO BE COMING INTO BETTER AGREEMENT AND INDICATES THE DRIER
AIR BEGINNING TO SPREAD EAST AND SOUTHEAST ACROSS SOUTH FLORIDA
THROUGH THE DAY SATURDAY. AS A RESULT...WILL INDICATE A GENERAL
DRYING PATTERN OR TRANSITION PERIOD THROUGH THE DAY SATURDAY FROM
NORTHWEST TO SOUTHEAST AS THE UPPER TROUGH MOVES THROUGH. THIS DRY
AIR COMBINED WITH SUBSIDENCE ON THE BACK SIDE OF THE TROUGH SHOULD
LEAD TO CLEARING CONDITIONS COME SATURDAY NIGHT. HOWEVER...THE
LATEST ECMWF 00Z RUN STILL REMAINS SLIGHTLY SLOWER WITH THIS DRIER
AIR SPREADING ACROSS THE AREA THROUGH THIS TIME AND CONTINUES TO
MAINTAIN A DECENT SOURCE OF DEEP LAYER MOISTURE REMAINING IN PLACE
ACROSS THE SOUTHEASTERN HALF OF THE AREA THROUGH A GOOD PORTION OF
THE AREA SATURDAY. CONSIDERING SOME UNCERTAINTIES WITH REGARD TO THE
DRIER AIR MOVING OVER THE AREA...WE WILL NOT COMPLETELY RULE OUT THE
POTENTIAL FOR ADDITIONAL RAINFALL THROUGH THE EARLY PORTION OF THE
DAY SATURDAY...ESPECIALLY ACROSS THE SOUTHEASTERN SECTIONS OF THE
LOCAL AREA. AS A RESULT...WILL KEEP THE RAINFALL CHANCES UP THROUGH
THE FIRST HALF OF THE DAY...MAINLY SOUTHEAST OF LINE EXTENDING
SOUTHWEST FROM PALM BEACH COUNTY TO NAPLES.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...PLENTY OF DEEP LAYER DRY
AIR AND SUBSIDENCE ALONG WITH THE PREVIOUSLY DISCUSSED FRONTAL
BOUNDARY MOVING INTO THE AREA WILL LIMIT THE RAINFALL CHANCES
THROUGH THE END OF THE SHORT-TERM FORECAST PERIOD. TEMPERATURES
WILL CLIMB BACK TO AROUND 90 THROUGH THIS TIME WITH THE WARMEST
CONDITIONS EXPECTED INLAND AND ACROSS THE EASTERN AREAS WITH THE
WESTERLY FLOW CONTINUING.
LONG TERM (MONDAY-WEDNESDAY)...
A LOW LEVEL RIDGE AXIS WILL ESTABLISH ITSELF OVER SOUTH FLORIDA
BY MONDAY AND REMAIN NEARLY STATIONARY THROUGH THURSDAY, WITH
TROUGHING OVER THE SOUTHEAST STATES. THIS WILL BRING AN EXTENDED
PERIOD OF MAINLY WEST TO SOUTHWESTERLY FLOW, WITH THE WARMEST
DAYTIME TEMPS OVER EASTERN AREAS. SUFFICIENT MOISTURE COMBINED
WITH DAILY SEA BREEZE FORMATION WILL BE ENOUGH TO RESULT IN
ISOLATED TO SCATTERED STORMS EACH AFTERNOON.
MARINE...
LIGHT TO MODERATE SOUTHERLY WINDS WILL CONTINUE THROUGH SATURDAY AS
A FRONTAL BOUNDARY APPROACHES FROM THE NORTHWEST. NUMEROUS TO
WIDESPREAD SHOWERS AND STORMS WILL CONTINUE TO IMPACT THE MARINE
AREAS THROUGH SATURDAY...WHICH WILL LEAD TO PERIODS WITH GUSTY WINDS
AND CHOPPIER CONDITIONS IN AND AROUND THE HEAVIER ACTIVITY. DRIER
CONDITIONS WILL BE ANTICIPATED SATURDAY NIGHT THROUGH MONDAY WITH
LIGHT WINDS AND LOW SEAS CONTINUING.
AVIATION...
AN AREA OF RAIN WITH EMBEDDED STORMS WILL CONTINUE TO MOVE
NORTHEAST FROM THE SOUTHEAST GULF OF MEXICO INTO THE SOUTH FLORIDA
THIS AFTERNOON...AND AFFECT ALL OF THE TAF SITES IN THE CWA. SO
WILL CONTINUE THE VCTS FOR ALL OF THE TAF SITES THROUGH 02Z.
THE THUNDERSTORM THREAT SHOULD END EARLY THIS EVENING...BUT THE
SHOWERS WILL CONTINUE THROUGH THE NIGHT AT ALL OF THE TAF SITES
UNTIL THE TROUGH OF LOW PRESSURE SWINGS THROUGH THE CWA FROM THE
WEST. SO WILL CONTINUE THE VCSH AFTER 02Z FOR TONIGHT FOR ALL OF THE
TAF SITES OF THE CWA.
THE VIS AND CEILINGS WILL REMAIN IN THE VFR CONDITIONS TONIGHT...BUT
COULD FALL DOWN INTO THE MVFR CONDITIONS THIS AFTERNOON WITH THE
PASSAGE OF THE RAINS AND THE THUNDERSTORMS.
THE WINDS WILL BE FROM THE SOUTHEAST AROUND 10 KNOTS THIS AFTERNOON
FOR ALL OF THE TAF SITES ACROSS SOUTH FLORIDA THIS
AFTERNOON...BEFORE SWINGING TO A SOUTHWEST DIRECTION AT 5 KNOTS OR
LESS TONIGHT MAINLY AFTER 2Z.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 86 74 88 75 / 60 20 10 10
FORT LAUDERDALE 84 76 87 77 / 70 20 10 10
MIAMI 86 76 91 77 / 60 30 20 10
NAPLES 84 73 88 74 / 40 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...14/MJB
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1217 AM CDT SAT JUN 2 2012
.AVIATION...06Z TAF. QUIET WEATHER WITH VFR CONDITIONS EXPECTED
FOR THIS TAF PERIOD...WITH ANY CLOUD COVER REMAINING IN THE
MID/UPPER LEVELS. TRICKY PART OF THIS TAF PERIOD LIES WITH THE
WINDS...AS A SURFACE RIDGE AXIS LINGERS AROUND THE AREA. WILL KEEP
THE VRB WIND DIRECTION GOING EARLY THIS MORNING THROUGH THE
AFTERNOON...BEFORE TURNING TO THE S/SE THIS EVENING AS THE AXIS
SLIDES EAST. SPEEDS WILL BE LIGHT...BETWEEN 5-10KTS.
&&
.PREV DISCUSSION... /ISSUED 1021 PM CDT FRI JUN 1 2012/
UPDATE...JUST COMPLETED AN UPDATE ADDRESSING ONLY THE OVERNIGHT
PERIOD THROUGH 12Z. PRIMARY CHANGE WAS TO LINGER A TOKEN 20
PERCENT CHANCE OF SHOWERS THROUGH 06Z ACROSS MAINLY THE EASTERN
1/2 OF THE CWA...AS RADAR TRENDS CONFIRM THAT POTENTIALLY SPOTTY
MEASURABLE RAIN WILL NOT BE OUT OF THE CWA BY 03Z AS EARLIER
FORECAST INDICATED. PULLED THUNDER WORDING FOR THE NIGHT...AS NO
LIGHTNING STRIKES HAVE BEEN DETECTED FOR A FEW HOURS NOW AND
REMAINING MUCAPE IS ALMOST NIL PER RUC-BASED MESOANALYSIS.
ALOFT...WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA CONFIRMS
FAIRLY SHARP NORTHWEST FLOW ALOFT...WITH THE LINGERING SHOWERS
CONCENTRATED WITHIN A CORRIDOR OF SUBTLE MID LEVEL SHORTWAVE
ENERGY AND AN 80-90KT UPPER LEVEL JET STREAK. AS THE NIGHT WEARS
ON...THIS MODEST UPPER SUPPORT SHOULD SLIDE OFF TO THE SOUTH AND
EAST OF THE CWA...AND THUS HAVE NO PRECIPITATION MENTION POST-06Z.
THAT BEING SAID...THE LATEST HRRR REFLECTIVITY PROG TRIES TO BRING
A NARROW BAND OF SPRINKLES/LIGHT SHOWERS ACROSS THE FAR SOUTHWEST
CWA BETWEEN 09Z-12Z...WHICH SEEMS TO BE TIED TO ANOTHER SUBTLE
RIBBON OF FRONTOGENESIS/THETA-E ADVECTION EVIDENT AROUND 700MB.
WILL OMIT THIS FROM THE FORECAST FOR NOW...BUT WOULD NOT SURPRISED
TO SEE IT FORM...AS THE LAST 18 HOURS HAVE AGAIN PROVEN THAT GETTING
CONSIDERABLE LEAD TIME ON LOW-IMPACT RAINFALL EVENTS IN NORTHWEST
FLOW IS NOTORIOUSLY CHALLENGING. TEMPERATURE WISE...MADE NO CHANGE
WHATSOEVER TO OVERNIGHT LOWS...STILL AIMING FOR UPPER 40S-LOW 50S.
PER LATEST HOURLY GFS LAMP GUIDANCE...THERE ARE HINTS THAT
LINGERING MID LEVEL CLOUDS COULD HOLD THINGS UP THINGS A FEW
DEGREES WARMER THAN ADVERTISED...BUT AFTER DIPPING BELOW FORECAST
LOWS THE PAST FEW MORNINGS AM NOT GOING TO BET ON IT. ALSO THERE
ARE SOME HINTS THAT LIGHT FOG COULD TRY FORMING LATE TONIGHT OVER
THE MOIST GROUND IN AREAS THAT SAW RAINFALL DURING THE PAST 18
HOURS...BUT CONFIDENCE IS LOW IN DEVELOPMENT GIVEN CONSIDERABLE
MID LEVEL CLOUDS THAT WILL ALSO OMIT THIS MENTION FROM GRIDS.
PREV DISCUSSION... /ISSUED 353 PM CDT FRI JUN 1 2012/
SHORT TERM...THROUGH SATURDAY. MORNING UPPER AIR ANALYSIS
INDICATES UPPER LEVEL TROUGHING OVER THE CENTRAL CONUS WITH
RIDGING OVER THE WEST AND EAST. MID AND UPPER LEVEL JET ENERGY
REMAINS POSITIONED FROM THE PACIFIC NORTHWEST...SOUTHEASTWARD INTO
THE CENTRAL PLAINS AND THEN NORTHEASTWARD INTO THE NORTHEASTERN
CONUS. MID-AFTERNOON WATER VAPOR IMAGERY SHOWS INCREASING MID
LEVEL MOISTURE FLOWING IN FROM THE PACIFIC INTO THE NORTHWESTERN
CONUS...AND SOUTHEASTWARD INTO THE CENTRAL PLAINS. A MID LEVEL LOW
IS NOTED OVER THE GREAT LAKES REGION...AND A MID LEVEL SHORT WAVE
OVER THE THE DAKOTAS. AT THE SURFACE AN AREA OF HIGH PRESSURE IS
NOTED NEAR KEMP...AND A TROUGH EXISTS FROM WESTERN NEBRASKA ON
SOUTH ALONG THE COLORADO/KANSAS BORDER. AS A RESULT...LOW LEVEL
FLOW GENERALLY REMAINS FROM THE SOUTH ACROSS OUR CWA.
GUIDANCE SUGGESTS THE MID LEVEL SHORT WAVE OVER THE DAKOTAS WILL
PUSH SOUTHEAST LATE THIS AFTERNOON THROUGH TONIGHT...THUS PROMOTING
A WEAK SURFACE LOW OVER THE UPPER MISSISSIPPI VALLEY WHICH SHOULD
HELP PULL THE WESTERN NEBRASKA SURFACE TROUGH EAST/SOUTHEAST ACROSS
OUR AREA. THE BULK OF THE THERMAL ADVECTION AND DPVA IN ASSOCIATION
WITH THE MID LEVEL SHORT WAVE SHOULD REMAIN EAST/NORTHEAST OF OUR
AREA...BUT JUST ENOUGH MID LEVEL OMEGA...ALONG WITH SOME LOW LEVEL
CONVERGENCE IN THE VICINITY OF THE SURFACE TROUGH...MAY BE ENOUGH TO
PROMOTE SOME PRECIPITATION ACROSS OUR NORTH AND EAST LATE THIS
AFTERNOON THROUGH THIS EVENING. RAIN FROM EARLIER TODAY HAS
ENCASED MUCH OF OUR CWA UNDER A MESO-HIGH AND WITH LOW LEVEL
MOISTURE QUITE LOW...INSTABILITY IS HARDLY ANYTHING TO GET EXCITED
ABOUT. THAT BEING SAID...VISIBILITY SATELLITE IMAGERY DOES
INDICATE CLOUDS BEGINNING TO BREAK ACROSS OUR NORTH/NORTHWEST AND
IF THIS TREND CONTINUES...IT IS POSSIBLE THAT WHAT LITTLE DIABATIC
HEATING WE RECEIVE THIS AFTERNOON...ALONG WITH SOMEWHAT INCREASING
MID LEVEL LAPSE RATES IN THE VICINITY OF THE MID LEVEL TROUGH AXIS
PASSING JUST TO OUR NORTHEAST...COULD PERHAPS PROMOTE ~100J/KG
DEEP LAYER MUCAPE. GIVEN ALL THIS...WILL GO AHEAD AND INCLUDE A
SLIGHT CHANCE POP ACROSS OUR NORTH AND EAST 21Z-03Z...WITH THUNDER
MENTION ALSO INCLUDED. SUBSIDENCE WILL SETTLE IN ACROSS THE AREA
BY 03Z TONIGHT AS THE MID LEVEL TROUGH AXIS PUSHES WELL
EAST/SOUTHEAST OF OUR AREA...AND WITH AN OVERALL LACK IN KINEMATIC
FORCING DRY CONDITIONS SHOULD THEN PRESENT THEMSELVES TO OUR AREA
THROUGH THE REMAINDER OF THE SHORT TERM FORECAST PERIOD.
BELOW-NORMAL LOWS ARE STILL EXPECTED TONIGHT AS SKIES CLEAR OUT AND
RELATIVELY HIGH PRESSURE REMAINS SITUATED OVER THE AREA. CLEARING
SKIES...DRY CONDITIONS AND A DOWN-SLOPING WESTERLY LOW LEVEL WIND
FIELD WILL THEN HELP PROMOTE A MUCH WARMER DAY ON SATURDAY...WITH
HIGHS IN THE 80S FORECAST FOR THE MOST PART.
LONG TERM...SATURDAY NIGHT THROUGH SUNDAY. BIGGEST CHALLENGE WILL
RECURRING CHANCES OF SHOWERS AND THUNDERSTORMS.
EXTENDED MODELS ARE IN PRETTY GOOD AGREEMENT...BUT THERE ARE SOME
DIFFERENCES IN THE LARGE SCALE SOLUTIONS.
FOR SATURDAY NIGHT...WE BEGIN WITH AN AMPLIFYING UPPER LEVEL PATTERN
WITH A RIDGE DEVELOPING OVER THE ROCKY MOUNTAINS/CENTRAL
PLAINS...FLANKED BY AN ALREADY DEEPLY AMPLIFIED MEAN TROUGH TO THE
EAST AND DEVELOPING TROUGH OVER THE NORTHERN ATLANTIC...ENTERING THE
PACIFIC NORTHWEST. BY LATE SATURDAY NIGHT A MODEST LOW-LEVEL JET
DEVELOPS OVER THE HIGH PLAINS AND NUDGES EAST...WITH THE THETA-E
AXIS MAKING ITS WAY INTO THE WESTERN CWA...HELPING TO GIVE US A BIT
OF A CHANCE OF SHOWERS AND THUNDERSTORMS. BULK SHEAR WILL BE
WEAK...AND INSTABILITY IS NOT IMPRESSIVE. THIS WILL NOT BE A
SCENARIO FOR WIDESPREAD STRONG OR SEVERE THUNDERSTORMS...MORE LIKE
AN ISOLATED STRONG STORM FOR THIS TIME PERIOD.
BY SUNDAY...THE INSTABILITY AXIS ASSOCIATED WITH A WEAK SURFACE
FRONT/TROUGH SHOULD BE SOMEWHERE OVER THE CWA...WHICH WILL HELP
SPARK SOME THUNDERSTORMS MAINLY IN THE AFTERNOON AND EVENING.
INSTABILITY WILL BE GREATER THAN SATURDAY NIGHT THANKS TO THE WEAK
BOUNDARY...SO WILL BE A BETTER SHOT AT A FEW SEVERE
THUNDERSTORMS...ALTHOUGH SHEAR WILL REMAIN WEAK AND INSTABILITY WILL
BE MODERATE.
THE SCENARIO OF MODERATE INSTABILITY AND LOW SHEAR WILL HOLD THROUGH
WEDNESDAY...ALTHOUGH IT APPEARS THAT CONVECTION SHOULD REMAIN IN THE
HIGH PLAINS FOR MONDAY AND TUESDAY. WILL KEEP CHANCES OF STRONG TO
SEVERE SHOWERS AND THUNDERSTORMS AROUND FOR TUESDAY NIGHT INTO
FRIDAY...BUT NO WIDESPREAD OUTBREAK IS ANTICIPATED AS OF NOW AS
SEVERE POTENTIAL LOOKS BEST IN THE HIGHER PLAINS. THE HEAT WILL ALSO
INCREASE QUITE A BIT UNDER THE RIDGE WITH HIGHS IN THE MID 80S TO
LOWER 90S FROM SUNDAY THROUGH WEDNESDAY. SO FOR MONDAY INTO
TUESDAY...KEEPING DRY EXCEPT SOME FAR WESTERN AREAS ON TUESDAY
AFTERNOON.
BY TUESDAY NIGHT...MODELS SHOW THAT THE MORE NEGATIVELY
TILTED UPPER LEVEL TROUGH TO THE WEST COULD INCLUDE A CLOSED LOW.
WHAT MODELS DO WITH THE LOW DIFFER TO SOME DEGREE...BUT I TEND TO
LIKE THE ECMWF/ECMWF ENSEMBLES SOLUTION FOR THE PAST CONSISTENCY. BY
THURSDAY...THE CLOSED LOW SHOULD JOIN WITH THE SEVERELY POSITIVELY
TILTED LONGWAVE TROUGH ON THE EAST FLANK OF THE CENTRAL RIDGE AND
THEN BISECT THE RIDGE ACROSS THE NORTHERN/CENTRAL PLAINS IN AN
WEST-EAST ORIENTATION. THE GFS DOES NOT SHOW THIS...BUT KEEPS THE
RIDGE IN TACT. AT THE SAME TIME...AT THE SURFACE THE ECMWF DEPICTS
AN INVERTED TROUGH STRETCHING INTO THE CWA FROM THE SOUTH. THIS
TROUGHINESS SHOULD GIVE US OUR BEST SHOT AT PRECIPITATION FOR THE
LONG TERM ON WEDNESDAY NIGHT/THURSDAY. THIS WOULD ALSO BE THE TIME
PERIOD THAT WOULD BE MORE FAVORABLE TOWARD POSSIBLE SEVERE WEATHER
AS WE HAVE A MORE FAVORABLE SYNOPTIC ENVIRONMENT AND STRONGER FOCUS
AT THE SURFACE. THIS SCENARIO IS A BIT DICEY TO PREDICT AND
CONFIDENCE IN THE SYNOPTIC SCALE EVOLUTION IS NOT THE
GREATEST...WITH SMALLER DETAILS BEING QUITE UNCERTAIN. A COOL DOWN
IS IN ORDER FOR THURSDAY INTO FRIDAY AS THE RIDGE GETS PINCHED WITH
HIGHS IN THE 70S BY FRIDAY.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
AVIATION...ADO
UPDATE...PFANNKUCH
SHORT...BRYANT
LONG...HEINLEIN
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
349 AM EDT SAT JUN 2 2012
.SYNOPSIS...
COOL...DRY AIR REMAINS IN PLACE...WITH MID AND UPPER DISTURBANCES
LINGERING THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
BROAD UPPER LEVEL TROUGH AXIS CROSSES TODAY. AREA REMAINS IN NW
FLOW ALOFT THROUGH TONIGHT WHILE SURFACE FLOW REMAINS W TO SW.
USED RUC ALGORITHM TO MIX DOWN GUSTS TO 20 TO 25 MPH THIS
AFTERNOON. SMALLER DISTURBANCES WITHIN THE LARGER TROUGH ARE HARDER
TO PICK OUT. IT LOOKS LIKE ONE OVER EASTERN OHIO EARLY THIS
MORNING IS PRODUCING NOTHING MORE THAN MID / HI CLOUD...AND IS
DESTINED FOR WESTERN PA. ANOTHER IS MORE EASILY EVIDENT OVER THE
MIDWEST...WHERE SPOTTY LIGHT RADAR ENERGY IS BEING RETURNED. THIS
ONE CROSSES SOUTHERN PORTIONS OF THE AREA THIS EVENING.
OTHERWISE THE NAM12 SEEMS TO HINT AT AN AXIS OF ENHANCED MOISTURE
AND INSTABILITY ACROSS NORTHERN PORTIONS OF THE FORECAST AREA LATER
THIS AFTERNOON. IT MAKES SENSE THAT THE HEATING OF THE EARLY JUNE
DAY BENEATH THE COOL AIR ALOFT SHOULD RESULT IN CONVECTION THIS
AFTERNOON...WITH THE HIGHEST CHANCE N WHERE HEIGHTS / TEMPERATURES
ALOFT ARE LOWEST.
FINALLY...LEANED TOWARD NAM12 ON CLOUDS TONIGHT WHICH SUGGESTS MORE
CLOUDS S AND PERHAPS LESS N WITH A DRY INTRUSION WORKING IN THERE
FROM THE W. EITHER WAY...SHOULD BE JUST ENOUGH CLOUD AND FLOW TO
PRECLUDE FOG AGAIN TONIGHT...ALTHOUGH LITTLE NERVOUS ABOUT CENTRAL
KY WITH 6 SM BR ON CLEARING DESPITE 5 KTS OF WIND. DO HAVE THE
ADDITIONAL DAY OF DRYING TODAY THOUGH.
BLENDED IN THE ADJMET 50/50 WITH PREVIOUS FCST FOR HIGHS TODAY AND
ONLY 25/50 FOR LOWS TONIGHT...SLIGHTLY HIGHER VALUES ESPECIALLY
TODAY.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
WEAK RIDGING ON SUNDAY WILL GIVE WAY TO ANOTHER DISTURBANCE
MAKING ITS WAY TOWARDS THE REGION BY SUNDAY NIGHT. THIS SYSTEM
HOWEVER WILL TRACK JUST TO OUR SOUTH DURING THE DAY ON MONDAY AND
EXITS MONDAY NIGHT...BUT MOISTURE WILL KEEP POPS IN THE FORECAST
AS IT DOES. YET ANOTHER SYSTEM MOVES ACROSS ON TUESDAY AND EXITS
ON TUESDAY NIGHT...KEEPING POPS IN THE FORECAST. TEMPERATURES WILL
BE COOLER THROUGHOUT WITH CLOUDS AND PRECIP AROUND.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THE EXTENDED WILL FEATURE A BLOCKING TYPE PATTERN WITH UPR LOW/TROF
ACROSS NE CONUS AND STOUT RIDGING ACROSS THE PLAINS. THIS KEEPS AREA
IN NW FLOW AND AT MERCY OF ANY DISTURBANCES ROTATING DOWN. MDLS ARE
STRUGGLING WITH TIMING AND PLACEMENT OF ANY DISTURBANCE COMING DOWN
THRU TROF. OTHERWISE...EXPECT MAINLY DRY AND SEASONABLE CONDITIONS.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
STRATOCU BECOMING MORE PATCHY OVERNIGHT THROUGH SAT MORNING AND THEN
MORE WIDESPREAD BUT CELLULAR SAT AFTERNOON. HEIGHTS MVFR AT TIMES
ESPECIALLY IN THE MOUNTAINS WHERE CIGS COULD DROP BELOW 2 KFT. CIGS
SHOULD RISE ON MIXING SAT FOR VFR AREA WIDE BY SAT AFTERNOON. CIGS
SHOULD STAY ABOVE THE MVFR THRESHOLD SAT NT.
NOTHING MORE THAN A SPRINKLE OVERNIGHT...THEN POP UP SHOWERS SAT
AFTERNOON ON THE HEATING OF THE DAY AND WEAK DISTURBANCES ALOFT. IT
MAY BECOME UNSTABLE ENOUGH OVER THE MIDDLE OHIO VALLEY FOR LATE DAY
THUNDER SAT. ANY SHOWER OR THUNDERSHOWER OVER AN AIRPORT WILL BRING
AT WORST BRIEF MVFR CIGS AND VSBYS.
W TO SW SFC FLOW GUSTY AT TIMES ESPECIALLY MIDDAY AND AFTERNOON SAT
WHILE FLOW ALOFT REMAINS MODERATE AND MAINLY FROM THE W.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF HOLES OPENING UP IN
STRATOCUMULUS CEILINGS...RESULTING IN JUST SCATTERED CLOUDS.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 06/02/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H M M M M H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H M M M M M M M M H
EKN CONSISTENCY H H H H H M H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY M M M M M M M H H H H H
AFTER 06Z SUNDAY...
NO WIDESPREAD IFR EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/TRM/30
NEAR TERM...TRM
SHORT TERM...JS
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
403 AM CDT SAT JUN 2 2012
.SHORT TERM...TODAY THROUGH SUNDAY.
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVING OVER LAKE HURON. LAST PIECE OF
ENERGY NOW SEEN ROTATING BACK TO THE WEST...NORTH OF THE
LOW...PUSHING CLOUDS AND PCPN BACK TOWARDS NORTHEAST WI. WHERE
CLOUDS REMAIN...OR MOVE INTO...THE TEMPERATURES ARE IN THE 40S OR
LOWER 50S. UNDER CLEAR SKIES OVER CENTRAL AND NORTH CENTRAL WI
TEMPS HAVE FALLEN OFF INTO THE 30S. SMALL PCPN CHANCES TODAY
REMAIN THE MAIN FORECAST CONCERN THIS PERIOD.
STACKED LOW TO LIFT SLOWLY NORTH THROUGH SUN MORNING...DEEPENING
SLIGHTLY THROUGH EARLY THIS MORNING. GIVEN PCPN TRENDS AT THIS
TIME...WILL KEEP SCATTERED POPS GOING...FAR NE AND DOOR COUNTY
THROUGH THIS MORNING...BACKING OFF THIS AFTERNOON AS LOWS
INFLUENCE DIMINISHES. AS IN PAST DAYS...MODELS SHOWING GOOD
INSTABILITY THIS AFTERNOON AND HINT AT WEAK SFC TROF/MOISTURE
CONVERGENCE MOVING OVER CWA THIS AFTERNOON. PROBLEM WITH THIS
FORECAST IS AMOUNT OF DRY AIR...WITH SOUNDINGS SHOWING RATHER DEEP
MIXING FOR GUSTY WEST WINDS AND DEW POINTS DROPPING INTO UPPER
30S TO LOWER 40S. THIS WOULD LIMIT ANY SB INSTABILITY. WILL STAY
WITH MAINLY ISOLD POPS AND LIMIT THUNDER TO SOUTH.
HEIGHTS TO RISE AS RIDGE TO WEST BUILDS IN SATURDAY NIGHT AND
SUNDAY WITH DRY FORECAST EXPECTED.
HAVE HELD TEMPS TO NEAR NORMAL LEVELS TODAY WITH CLOUDS...THOUGH
RETURNING TO ABOVE NORMAL HIGHS ON SUN.
.LONG TERM...SUNDAY NGT THRU NXT FRI. MAIN FCST CONCERN REMAINS
THE EXTENT OF PCPN DURING THE PERIOD AND TRYING TO ATTEMPT TO
ASCERTAIN EXACTLY WHICH DAYS TO FOCUS ON. ANY PCPN APPEARS TO BE
RELATIVELY LIGHT AND SCATTERED AT BEST. TEMPS ARE NOT EXPECTED TO
CHANGE MUCH NXT WEEK WITH READINGS GENERALLY CLOSE TO NORMAL.
MDLS CONT TO INDICATE A MID-LVL PIECE OF SHORTWAVE ENERGY MOVING
THRU THE CNTRL CONUS UPR RDG...THEN DIVING SE THRU THE UPR MS
VALLEY AND INTO THE WRN GREAT LKS/MIDWEST SUNDAY NGT. THERE
APPEARS TO BE A QUASI-STNRY BOUNDARY SITUATED FROM MN S-SE INTO IA
AND THIS BOUNDARY COULD HELP FOCUS THE SHWR POTENTIAL MORE TO OUR
SW IN THE CONVERGENCE ZONE. THIS FEATURE IS NOW A LITTLE SLOWER
THAN LAST NGT`S MDL RUNS...THUS HAVE FOCUSED ANY PCPN TIL AFTER
MIDNIGHT AND PRIMARILY OVER CNTRL WI. THIS DELAY IN PCPN COULD
ALLOW FOR TEMPS TO DROP A COUPLE OF MORE DEGS THAN ORIGINALLY
THOUGHT WITH READINGS AROUND 50 NORTH TO THE MIDDLE 50S CNTRL/
E-CNTRL WI.
WHILE THE SHORTWAVE CONTS TO TREK SE TOWARD THE OHIO RIVER VALLEY
ON MON...THE MDLS SHOW A SHORTWAVE TROF ROTATING SWD THRU THE
GREAT LKS AROUND THE LARGE ERN CONUS UPR TROF. THE COMBINATION OF
THIS TROF WITH DAYTIME HEATING (INCREASING INSTABILITY) WL HELP TO
DEVELOP SOME SHWR ACTIVITY ALONG WITH AN ISOLATED TSTM. MAX TEMPS
WL BE DEPENDENT ON HOW FAST ANY PCPN CAN DEVELOP...THUS READINGS
COULD TOP OUT ANYWHERE IN THE 70S.
THE LOSS OF DAYTIME HEATING AND THE DEPARTURE OF THE SHORTWAVE
TROF WL END ANY LINGERING SHWR THREAT MON EVENING. OTHERWISE...AN
AREA OF CANADIAN HI PRES IS FCST TO BEGIN DROPPING SOUTH INTO THE
GREAT LKS LATER MON NGT BRINGING PARTLY CLOUDY SKIES AND SLIGHTLY
COOLER CONDITIONS. WE WL SEE MIN TEMPS RANGE FROM THE UPR 40S TO
THE MID 50S E-CNTRL WI.
THE HIGHLY AMPLIFIED FLOW ACROSS THE CONUS REMAINS INTACT THRU THE
MIDDLE OF NXT WEEK WITH DEEP UPR TROFS OVER THE WRN U.S./ERN U.S.
AND A NARROW UPR RDG OVER THE MIDDLE OF THE COUNTRY. NE WI TO
RESIDE ON THE ERN SIDE OF THE RDG...BUT ALSO SIT ON THE WRN FLANK
OF THE ERN U.S. UPR TROF. THIS LEAVES THE FCST AREA VULNERABLE TO
ADDITIONAL SHORTWAVE TROFS OR INDIVIDUAL SHORTWAVES MOVING THRU
THE BADGER STATE AND KICKING OFF A FEW SHWRS...ESPECIALLY DURING
THE PEAK HEATING OF THE AFTERNOON. THIS SCENARIO WOULD RUN FROM
TUE THRU AT LEAST THU BEFORE THE UPR RDG SLIDES FAR ENUF EAST TO
POTENTIALLY CAP THE ATMOSPHERE BY THE TIME FRI ROLLS AROUND. DUE
TO THE GENERAL UNCERTAINTY IN TRYING TO TIME EACH OF THESE LITTLE
WEATHER ELEMENTS...HAVE FOLLOWED THE CONSENSUS MDL SOLUTION WHICH
POINTS TO LOW CHC POPS MAINLY DURING THE DAYLIGHT HOURS. AS FOR
TEMPS...READINGS SHOULD BE FAIRLY CONSISTENT DUE TO LITTLE CHANGE
IN AIR MASS. LOOK FOR TEMPS TO END UP CLOSE TO CLIMATOLOGICAL
NORMALS NXT WEEK.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH SATURDAY EVENING.
DEEPER MOISTURE AND UPPER LEVEL DISTURBANCES ROTATING AROUND A
GREAT LAKES UPPER LOW WILL BRING SOME SHOWERS TO FAR NE WI...
ESPECIALLY DOOR COUNTY...THROUGH SATURDAY EVENING. FORECAST
SOUNDINGS INDICATE THAT MARGINAL LLWS IS POSSIBLE EARLY SATURDAY
MORNING...BUT APPEARS TO BE TOO BORDERLINE TO ADD TO THE 06Z TAFS.
WILL HAVE SOME INSTABILITY FOR SHOWER CHANCES SATURDAY AFTERNOON...
AND HAVE ADDED VCSH FOR AUW/CWA/GRB/ATW FROM MID-AFTERNOON
THROUGH EARLY EVENING. NW WINDS WILL ALSO TURN GUSTY BY LATE
SATURDAY MORNING...WITH GUSTS OVER 25 KTS POSSIBLE. THE WIND
SHOULD SUBSIDE BY EARLY SATURDAY EVENING.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
TE/KALLAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 PM CDT FRI JUN 1 2012
.SHORT TERM...TONIGHT THROUGH MONDAY
247 PM CDT FRI JUN 1 2012
FORECAST CHALLENGES MAINLY CENTERED AROUND SHOWER/ISOLATED THUNDER
CHANCES THROUGH THE PERIOD.
CURRENT WATER VAPOR AND RAP 500MB ANALYSIS SHOW A CLOSED LOW OVER
LAKE MICHIGAN WHILE A WEAK MID-LEVEL TROUGH WAS ROTATING SOUTHEAST
THROUGH ND. COLD POOL ALOFT ASSOCIATED WITH THE LAKE MICHIGAN LOW
WAS PRODUCING STEEP TEMPERATURES LAPSE RATES AND EXTENSIVE CUMULUS
FIELD ACROSS THE FORECAST AREA. RADAR QUIET AT THIS POINT WITH NO
SIGNIFICANT ECHOES/SHOWERS INDICATED. MEANWHILE...FORCING ASSOCIATED
WITH THE WAVE UPSTREAM OVER ND WAS PRODUCING SCATTERED SHOWERS/ISOLD
THUNDER ACROSS ACROSS EASTERN ND INTO EASTERN NEB. OTHERWISE...
TEMPERATURES ACROSS THE FORECAST AREA THIS AFTERNOON WERE IN THE MID
60S TO AROUND 70 DEGREES.
01.12Z NCEP MODELS AND 01.09Z SREF SHOWING GOOD AGREEMENT WITH
HANDLING OF SYNOPTIC PATTERN THROUGH SUNDAY. GFS A BIT DEEPER WITH
THE MID-LEVEL WAVE ROTATING ACROSS ACROSS THE AREA MONDAY FOR BETTER
SATURATION/RAINFALL POTENTIAL. GENERALLY WENT WITH A CONSENSUS BLEND
AS A RESULT.
FOR TONIGHT...WILL BE WATCHING THE WAVE OVER ND ROTATE SOUTHEAST
WHILE DAMPENING OUT SOME. THE WAVE IS EXPECTED TO SCOOT SOUTHEAST
INTO IA BY 12Z. MOST OF THE FORCING...IE PV-ADVECTION/ISENTROPIC
LIFT AND MOISTURE TRANSPORT AND RESULTANT -SHRA CHANCES EXPECTED TO
BE TIED VERY CLOSE TO THE WAVE ITSELF AND JUST SOUTHWEST OF THE
AREA. HI-RES MESO MODELS ALSO SHOWS ACTIVITY REMAINING MAINLY
SOUTHWEST OF THE AREA. MAINTAINED JUST A SLIGHT -SHRA CHANCE
BASICALLY SOUTHWEST OF A LINE FROM AUSTIN MN TO OELWEIN IA AFTER 03Z
UNTIL 12Z. REST OF THE AREA/BASICALLY EAST OF THE MISSISSIPPI RIVER
SHOULD SEE CLEARING SKIES. THE CLEARING SKIES AND VERY LIGHT
NORTHWEST WINDS ARE EXPECTED TO PRODUCE FAIRLY CHILLY TEMPERATURES
OVERNIGHT...MAINLY IN THE FAVORED COLD SPOT AREAS SUCH AS
SPARTA/BLACK RIVER FALLS. WILL LIKELY SEE TEMPERATURES DIP INTO THE
UPPER 30S IN THOSE AREAS. ELSEWHERE...EXPECT TEMPERATURES MAINLY IN
THE 40S.
FOR SATURDAY...CLOSED LOW WILL DEEPEN SOME OVER LAKE HURON.
ASSOCIATED COLD POOL/CYCLONIC FLOW ALOFT WILL RESIDE OVER THE AREA
WITH 0-3KM MUCAPE AROUND 800J/KM AND MLCAPE AROUND 500J/KG. THIS
SHOULD BE SUFFICIENT ENOUGH FOR SHRA CHANCES ALONG WITH ISOLD
THUNDER. NAM SHOWING ABOUT 15-16 PVU/S ADVECTING SOUTHEAST ACROSS
AREAS NORTHEAST OF I-94 FOR PERHAPS A BETTER SHOT AT THUNDER
ACTIVITY. OTHERWISE...WITH EXTENSIVE CUMULUS AND ISOLD/SCT SHRA
ACTIVITY...TEMPERATURES ARE EXPECTED TO REMAIN SLIGHTLY BELOW NORMAL
IN THE UPPER 60S TO LOWER 70S. A FEW SHOWERS EXPECTED TO LINGER INTO
EARLY SATURDAY EVENING MAINLY NORTHEAST OF I-94. LOOK FOR CLEARING
SKIES THEN THROUGH THE REMAINDER OF THE OVERNIGHT HOURS AS SURFACE
HIGH PRESSURE DRIFTS OVER THE REGION WITH LOWS FALLING INTO THE
MIDDLE 40S TO LOWER 50S.
LATEST MODELS ARE TRENDING A BIT FASTER/STRONGER WITH A MID-LEVEL
TROUGH MOVING SOUTHEAST OUT OF THE NORTHERN PLAINS ON SUNDAY.
AFFECTS OF THIS WAVE WILL BE INCREASING MID-LEVEL CLOUDS THROUGH THE
AFTERNOON WITH A CHANCE OF SHRA/ISOLD THUNDER. THIS WILL BE MANLY
NORTHWEST OF A LINE FROM NEILLSVILLE AND ARCADIA WI...TO CHARLES
CITY IA WHERE NOSE OF 850-700MB MOISTURE TRANSPORT/ISENTROPIC LIFT
WILL BE DIRECTED. LOOK LIKE TEMPERATURES SHOULD BE RIGHT AROUND
NORMAL IN THE MID-UPPER 70S.
LOOK FOR THE MID-LEVEL TROUGH TO ROTATE OVER/ACROSS THE AREA SUNDAY
NIGHT INTO MONDAY FOR A GOOD CHANCE OF SHRA/ISOLD THUNDER. HIGHS
SUNDAY AND MONDAY ARE EXPECTED TO CONTINUE RIGHT AROUND NORMAL IN
THE MID 70S TO A FEW LOWER 80S.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
247 PM CDT FRI JUN 1 2012
01.12Z GFS/ECMWF APPEAR TO BE HAVING PROBLEMS RESOLVING WHERE
EXACTLY OMEGA BLOCK HIGH IS GOING TO SET UP THROUGH THE PERIOD. THE
GFS/ECMWF SEEM TO HAVE FLIP-FLOPPED WITH EACH OTHER/S SOLUTION.
EITHER WAY...APPEARS THE AREA WILL REMAIN JUST EAST OF THIS
RIDGE/OMEGA BLOCK AND WILL BE SUSCEPTIBLE TO CYCLONIC FLOW ALOFT
WITH EMBEDDED IMPULSES. THIS YIELDS SLIGHT CHANCE OF SHOWERS EACH
DAY. OTHERWISE...HIGH TEMPERATURES SHOULD REMAIN RIGHT AROUND NORMAL
LEVELS IN THE 70S.
&&
.AVIATION...THROUGH 06Z SUNDAY
1141 PM CDT FRI JUN 1 2012
SKIES HAVE CLEARED OUT OVER THE AREA THIS EVENING AND EXPECT THEM
TO REMAIN THAT WAY INTO SATURDAY MORNING. THE REMAINING SHOWERS
OVER SOUTHWEST MINNESOTA HAVE SHOWN A SLOW DECREASING TREND WHILE
MOVING TO THE SOUTH/SOUTHEAST. EVEN IF THESE HOLD TOGETHER THROUGH
THE NIGHT...THEY WILL REMAIN WEST OF KRST AND THE SATELLITE LOOP
INDICATES THE CLOUDS WILL AS WELL. DIURNAL CUMULUS ARE EXPECTED TO
DEVELOP LATE SATURDAY MORNING OR EARLY IN THE AFTERNOON. LAPSE
RATES WILL ONCE AGAIN BECOME PRETTY STEEP IN THE LOW LEVELS AND
WITH THE CYCLONIC FLOW ALOFT...THIS WILL BE ENOUGH TO CAUSE THE
CLOUDS TO FORM. BEST CHANCES FOR ANY SHOWERS SHOULD BE OVER
WISCONSIN UNDER THE COLDEST AIR ALOFT...BUT EVEN THERE...THE
COVERAGE WILL BE ISOLATED AT BEST AND NOT ENOUGH TO WARRANT AN
INCLUSION IN THE FORECAST AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CDT FRI JUN 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS GLASGOW MT
927 AM MDT SAT JUN 2 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH MONDAY...
MORNING UPDATE...
HAIL AND HEAVY RAINS LOOK TO BE THE MAIN IMPACT WITH THE PASSAGE
OF AFTERNOON SHOWERS. HOWEVER... AN INITIAL BURST OF STRONG WINDS WITH
PASSING THUNDERSTORMS WILL ALSO BE POSSIBLE UNTIL THE DRY SURFACE
LAYER MOISTENS IN THE LATE AFTERNOON AND EVENING. INITIATION LOOKS
TO BE AROUND 2 PM FOR CELLS OVER PHILLIPS AND PETROLEUM COUNTY AND
REACHING GLASGOW AND JORDAN BETWEEN 3 AND 5 PM. AREAS SUCH AS THE
YELLOWSTONE VALLEY AND MEDICINE LAKE ARE NOT ANTICIPATED TO
EXPERIENCE THUNDER UNTIL AROUND OR AFTER 6PM AS THE REMAINDERS OF
A LINE MOVES THROUGH. UPDATED AFTERNOON CLOUD COVER TO MOSTLY
CLOUDY AND BLENDED GRIDS TOWARDS HRRR AND HIRES ARM MESOSCALE
MODELS IN WIND FIELDS TO ACCOUNT FOR THIS LINE OF SHOWERS AND
THUNDER ANTICIPATED LATER TODAY. GAH
PREVIOUS SHORT TERM DISCUSSION...
A LARGE UPPER LEVEL LOW OF THE GULF OF ALASKA WILL EJECT A
SHORTWAVE OVER THE NORTHERN ROCKIES. THIS WILL PUSH AN INVERTED
SURFACE TROUGH AND COLD FRONT ACROSS CENTRAL AND EASTERN MONTANA
THIS AFTERNOON AND EVENING. EXPECT CONVECTION TO BEGIN TO FIRE
AHEAD OF THE INVERTED TROUGH ACROSS THE HIGHER ELEVATIONS. THESE
STORMS WILL PROBABLY MOVE INTO EASTERN MONTANA AND SHOULD PACK A
PUNCH WITH DAMAGING SURFACE WINDS AHEAD OF THESE THUNDERSTORMS AS
THEY FORM INTO A LINE. CAPE VALUES OF AROUND 500 J/KG AND VERTICAL
VELOCITIES OF BETWEEN 31 AND 60 M/S SHOW UPDRAFTS COULD BRIEFLY
SUPPORT COULD BE SOME HAIL WITH THESE STORMS BUT STILL THINK THE
BIGGEST THREAT WILL BE FROM STRONG WINDS. LCL WILL LOWER IN THE
RAIN COOLED AIR AND THE THREAT OF DAMAGING WINDS WILL DIE OFF.
PRECIPITABLE WATER LEVEL ON FORECAST SOUNDING ARE OVER AN INCH SO
MINOR FLOODING AND SMALL STREAM FLOODING IS POSSIBLE WITH THESE
STORMS...ESPECIALLY SINCE THE GROUND IS ALREADY SATURATED. BUT THE
FACT THAT THESE STORMS WILL BE MOVING BETWEEN 15 AND 20 KNOTS AND
WON`T BE TRAINING OVER THE SAME AREA MEANS FLASH FLOODING
IS NOT EXPECTED.
SUNDAY AND BEYOND EXPECT COOLER HIGHS ON SUNDAY BEHIND THE FRONT
WITH WEAK SHORTWAVE RIDGING FOR MONDAY WHICH WILL WARM THINGS UP
INTO THE 80S ONCE AGAIN. MONDAY AFTERNOON A FEW WIDELY SCATTERED
THUNDERSTORMS ARE POSSIBLE ACROSS THE WESTERN ZONES. EVERYONE ELSE
SHOULD REMAIN DRY. RSMITH
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
EXTENDED BEGINS WITH A RIDGE OVER NORTHEAST MONTANA WHICH SLOWLY
IS FORCED EAST BY THE DIGGING TROUGH OVER THE UPPER GREAT BASIN.
THE FLOW BECOMES SOUTH-SOUTHEAST AT ALL LEVELS WHICH MAKES IT A
VERY INTERESTING SYSTEM.
BOTH THE GFS AND ECMWF HAVE DIFFERENT PERIODS OF CONVECTION THROUGH
THE EXTENDED. NO GOOD EVENTS TIMED OUT OTHER THAN NEXT SATURDAY
NIGHT INTO SUNDAY WITH A COLD FRONT. THEREFORE WILL KEEP WITH THE
CLIMO OF SLIGHT CHANCE TO CHANCE OF THUNDERSTORMS THROUGH THE
PERIOD. THE CONVECTION SHOULD FOLLOW TYPICAL DIURNAL AFTERNOON
AND EVENING BEST CHANCES... LESS DURING THE OVERNIGHT AND MORNING
HOURS. PROTON
&&
.AVIATION...
VFR. THE EXCEPTION WILL BE WITH AFTERNOON AND EVENING CONVECTION.
THUNDERSTORMS WILL PRODUCE BRIEF PERIODS OF IFR WITH HEAVY RAIN
FROM 21Z-03Z MAINLY STARTING EARLY IN THE SOUTHWEST AND
PROPAGATING NORTHEAST. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
920 AM MDT SAT JUN 2 2012
.SHORT TERM...VALID FOR TDY AND SUN...
MINOR CHANGES WERE MADE TO TODAY/S FORECAST IN ORDER TO CARRY SOME
20 TO 30 PERCENT POPS FROM LIVINGSTON TO RED LODGE THIS MORNING. A
SLIGHT CHANCE OF STORMS WAS ALSO ADDED FURTHER EAST INTO THE MILES
CITY AND BROADUS AREAS BEFORE 00 UTC. THE MAIN FORECAST THEME THAT
WE HAVE BEEN ADVERTISING FOR A FEW DAYS REMAINS IN TACT...ALTHOUGH
THERE IS SOME CONCERN THAT EARLIER-THAN-EXPECTED CONVECTION MAY BE
THROWING SOME WRINKLES INTO OUR EXPECTATIONS.
AS OF MID MORNING...CONVECTION IS ALREADY MOVING OVER SOUTHWESTERN
MT...WITH EXTRAPOLATION TAKING IT INTO THE LIVINGSTON AREA BETWEEN
16 AND 18 UTC. THIS APPEARS ASSOCIATED WITH A WEAK PERTURBATION IN
THE SOUTHWEST FLOW ALOFT AHEAD OF THE MORE DYNAMIC SHORT WAVE THAT
WE HAVE BEEN COUNTING ON FOR STORMS LATER TODAY. EVEN SO...MOST OF
THE HIGH-RESOLUTION...CONVECTION-ALLOWING GUIDANCE PICKS UP ON THE
EARLY-DAY ACTIVITY AND TAKES AT LEAST SOME REMNANTS OF IT INTO THE
PLAINS OF SOUTHEASTERN MT DURING THE AFTERNOON. THAT AIR MASS WILL
HAVE HEATED AND DESTABILIZED BY THEN...SO THE 12 UTC HRRR COULD BE
CORRECT IN SHOWING SOME STRENGTHENING OF THE STORMS BEFORE 00 UTC.
MEANWHILE...THE SURFACE COLD FRONT WILL REMAIN BACK TO THE WEST...
AND THOSE SAME HIGH-RESOLUTION MODELS STILL SIMULATE NEW STORMS ON
THAT FRONTAL ZONE DURING THE AFTERNOON. SO LONG AS DEBRIS FROM THE
FIRST BATCH OF CONVECTION DOES NOT HINDER HEATING TOO MUCH...THERE
WILL STILL BE 500 T0 1000 J/KG OF MLCAPE TO WORK WITH...SO WE FEEL
THAT SCATTERED STORMS WILL INDEED FORM OVER SOUTH CENTRAL MT AHEAD
OF THE COLD FRONT. THAT IS SUPPORTED EVEN BY THE 12 UTC NAM. THERE
WILL BE SOME SEVERE WIND OR HAIL POTENTIAL WITH 30 TO 40 KT OF 0-6
KM BULK WIND SHEAR. SCHULTZ
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
MODEL DIFFERENCES CONTINUED WITH THE HANDLING OF THE PACIFIC SYSTEM
FOR NEXT WEEK. UPPER LOW THAT WILL AFFECT THE REGION WAS SEEN ON
WATER VAPOR IN THE GULF OF AK EARLY THIS MORNING. THIS SYSTEM WAS
FORECAST TO DIG INTO THE PACIFIC NW MON AND MON NIGHT...THEN BECOME
NEGATIVELY TILTED TUE AND TUE NIGHT AS IT APPROACHED THE REGION. THE
GFS ROTATED THE SYSTEM N THROUGH THE PACIFIC NW THROUGH TUE NIGHT
WHILE THE ECMWF HAD THE SYSTEM CENTERED OVER ID BY 12Z WED. THE GEM
WAS SIMILAR...AND HAS BEEN...TO THE ECMWF. AS HAS BEEN
ADVERTISED...THE MODELS CONTINUED TO BUILD DRY AIR AND A THERMAL
RIDGE OVER THE FORECAST AREA THROUGH TUE NIGHT. MOISTURE INCREASED
OVER THE AREA IN THE ECMWF ON WED...WHILE THE GFS LIFTED THE SYSTEM
N AND KEPT A DRIER AIRMASS IN PLACE. THE MODELS AGREED ON DEVELOPING
A STRONG 850 MB JET OVER THE EASTERN PART OF THE AREA MON NIGHT INTO
WED. THE GFS CONTINUED TO FORECAST VERY HIGH MOST UNSTABLE CAPES TUE
AND TUE NIGHT...SO ANY THUNDERSTORMS THAT DEVELOP WILL HAVE THE
POTENTIAL OF BECOMING SEVERE. HOWEVER...CHANCES FOR THUNDERSTORMS
WILL BE HINDERED BY THE STRONG WARMING ALOFT AND THE DRY AIRMASS.
GIVEN THE ABOVE DIFFERENCES IN THE HANDLING OF THE SYSTEM...MADE
VERY FEW POP CHANGES THROUGH THE MIDDLE OF THE WEEK. ON MON...DID
CONFINE POPS FROM KBIL W AS THE E LOOKED TOO DRY TO SUPPORT
PRECIPITATION. KEPT POPS ACROSS THE ENTIRE AREA MON NIGHT...AND LOW
POPS OVER THE REGION ON TUE. WITH MOISTURE POSSIBLY INCREASING OVER
THE AREA ON TUE NIGHT...HAD MOSTLY CHANCE POPS OVER THE AREA. ON
WED...KEPT CHANCE POPS E AHEAD OF THE SYSTEM/S COLD
FRONT...OTHERWISE HAD SLIGHT CHANCE DUE TO THE MOISTURE DIFFERENCES
IN THE MODELS. DUE TO THE WARM AIRMASS AND GOOD MIXING...RAISED HIGH
TEMPERATURES MON AND TUE. HIGHS IN THE 90S APPEARED
POSSIBLE...SHOULD MODELS CONTINUE TO DEPICT A WARM AND DRY
SCENARIO.
MODEL DIFFERENCES IN THE PATTERN CONTINUED THROUGH THE REST OF THE
PERIOD. HOWEVER...ON SAT AND SAT NIGHT...BOTH THE GFS AND ECMWF HAD
AN UPPER LOW AND ASSOCIATED COLD FRONT MOVING INTO THE AREA. SO
CONTINUED THE SLIGHT CHANCE POPS THROUGH FRI NIGHT AND WENT WITH
CHANCE POPS AT THE END OF THE PERIOD. MADE LIMITED TEMPERATURE
ADJUSTMENTS BEYOND TUE DUE TO THE UNCERTAINTY. OVERALL...IT WILL BE
COOLER THAN MON AND TUE. ARTHUR
&&
.AVIATION...
AN UPPER LEVEL DISTURBANCE AHEAD OF A SURFACE COLD FRONT WILL
SPREAD SHOWERS AND THUNDERSTORMS OVER KLVM BY LATE MORNING.
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON OVER THE WESTERN AREAS AS A COLD FRONT MOVES THROUGH.
THE FRONT WILL ALLOW SHOWERS AND THUNDERSTORMS TO DEVELOP OVER
KLVM AND EAST THROUGHOUT THE DAY. THERE IS A POTENTIAL FOR SOME
OF THESE THUNDERSTORMS TO CONTAIN VERY STRONG WINDS AND LARGE
HAIL MAINLY WEST AND NORTH OF KBIL. PRECIPITATION WILL BRING
WIDESPREAD MOUNTAIN OBSCURATION THIS AFTERNOON AND EVENING.
RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 087 054/080 057/090 062/091 056/073 048/070 050/073
4/T 52/T 22/T 32/T 32/T 22/T 22/W
LVM 083 047/080 049/088 053/089 046/064 039/067 041/073
6/T 53/T 34/T 32/T 43/T 22/T 22/W
HDN 088 057/081 055/090 061/094 056/077 048/072 050/076
2/T 51/B 21/B 22/T 22/T 22/T 22/W
MLS 089 057/080 059/091 065/093 061/079 052/073 054/076
2/T 51/B 11/B 22/T 33/T 22/T 22/W
4BQ 087 058/079 056/089 063/091 059/080 051/072 052/076
2/T 31/B 11/B 22/T 23/T 22/T 22/W
BHK 085 058/077 057/086 060/086 057/079 051/073 053/075
1/B 51/B 11/B 22/T 33/T 32/T 22/W
SHR 085 050/081 054/087 060/091 055/075 046/069 047/072
2/T 31/B 21/B 21/B 22/T 22/T 22/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS GRAND FORKS ND
1052 AM CDT SAT JUN 2 2012
.DISCUSSION...
TODAY WILL BE MOSTLY SUNNY...DRY AND WARM. SURFACE RIDGE AXIS
ACROSS THE CENTRAL DAKOTAS IS FORECAST TO SLIDE ACROSS THE
FORECAST AREA TODAY...ALLOWING LIGHT NORTHWEST WIND TO GRADUALLY
SHIFT TO THE SOUTH FROM WEST TO EAST THROUGH THE DAY. RUC 850 TO
500 HPA RH SUGGESTS SOME MID-HIGH LEVEL CLOUDS MOVING ACROSS
PORTIONS OF NORTHEAST ND. SURFACE TO 850 HPA LAYER IS DRY...BUT
GFS/NAM BUFR SOUNDINGS SHOW MID-AFTERNOON CONVECTIVE TEMPERATURES
A DEGREE OR TWO BELOW FORECAST HIGHS...SO SOME THERMAL CUMULUS
DEVELOPMENT IN THE 8 TO 9 KFT LAYER IS ALSO POSSIBLE. HIGH
TEMPERATURES TODAY WILL RANGE FROM THE LOW 70S ACROSS LAKES
COUNTRY TO THE UPPER 70S ALONG THE VALLEY FLOOR. OVERALL...
FORECAST IS IN GOOD SHAPE WITH ONLY MINOR ADJUSTMENTS NECESSARY TO
ACCOUNT FOR MOST RECENT OBSERVATIONAL TRENDS.
&&
.AVIATION...
EXPECT VFR CONDITIONS TODAY WITH ONLY FEW-SCT MID AND UPPER LEVEL
CLOUDS. LIGHT NORTHWEST WIND THIS MORNING WILL GRADUALLY SHIFT TO
THE SOUTH ACROSS EASTERN ND THIS AFTERNOON AS SURFACE RIDGE AXIS
MOVES ACROSS THE REGION.
&&
.PREV DISCUSSION... /ISSUED 340 AM CDT SAT JUN 2 2012/
DISCUSSION...FORECAST CHALLENGES CONCERN TEMPERATURES AND PCPN
CHANCES SUNDAY. MODELS IN REASONABLE AGREEMENT THROUGH PERIOD WITH
NO REAL PREFERENCE.
IN THE NEAR TERM WILL MONITOR FOR ANY EARLY AM FOG POTENTIAL.
OTHERWISE SHORTWAVE RIDGE WILL BUILD OVER FA TODAY. CLOUD COVER
TODAY WILL LIKELY BE SOME CI SPILLING OVER RIDGE...LINGERING MID
LEVEL CLOUD COVER AND PERHAPS SOME HIGH BASED CU DEVELOPMENT THIS
AFTERNOON. ANY OF ABOVE NOT LIKELY TO HAVE A BIG IMPACT ON
TEMPERATURES AS SHOULD BE SCT. SOLAR COMBINED WITH WEAK WARM
ADVECTION SHOULD ALLOW TEMPERATURES TO RECOVER TO AT OR A LITTLE
ABOVE SEASONAL AVERAGES.
WARM ADVECTION AHEAD OF NEXT WAVE AND ADVANCING CLOUDS WILL HOLD
TEMPERATURES UP TONIGHT. PRECIPITATION OF SOME DEGREE OF COVERAGE
SHOULD ORGANIZE ACROSS WESTERN/CENTRAL ND LATE AS WARM ADVECTION
MAXIMA AND DEEPER LAYERED RH MOVES IN. WITH MODEST LOW LEVEL JET
SOME OF THIS COULD REACH WESTERN AREAS TOWARDS MORNING AND WILL
MAINTAIN POPS. WITH MINOR MODEL DIFFERENCES ON HOW FAR EAST PCPN
WILL PROPAGATE AND COVERAGE WILL KEEP POPS ON THE LOW END.
PRECIPITABLE H20 VALUES INCREASE TO GREATER THAN AN INCH HOWEVER
INSTABILITY PARAMETERS NOT VERY IMPRESSIVE HOWEVER WILL MAINTAIN
THUNDER MENTION...LOOKS BEST ACROSS THE SOUTH.
BEST UPPER SUPPORT DURING THE DAY STILL ACROSS SOUTHERN CANADA. SO
APPEARS FAVORED AREAS FOR ANY PCPN WILL BE ACROSS THE NORTH CLOSER
TO UPPER SUPPORT AND THE SOUTH CLOSER TO BETTER LOW LEVEL
CONVERGENCE FROM SURFACE LOW AND GREATER INSTABILITY AND MOISTURE.
WILL FOCUS HIGHER POPS IN THESE AREAS. TEMPERATURES WILL BE TRICKY
DEPENDENT ON CLOUD COVER HOWEVER WITH THERMAL RIDGE AXIS OVER FA ANY
BREAKS WILL BOOST TEMPERATURES. WILL HOLD CLOSE TO PERSISTENCE WITH
READING AT OR ABOVE TODAYS ANTICIPATED MAX TEMPERATURES.
SURFACE BOUNDARY REACHES VALLEY BY EVENING SO ANY LINGERING PCPN
SHOULD BE EAST OF FRONT ACROSS MN. COLUMN DOES NOT COOL GREATLY SO
MINIMUMS SHOULD HOLD IN THE 50S.
HIGH PRESSURE BUILDS IN MONDAY AND THERMAL PROFILES SHOWING NOT MUCH
CHANGE SO TEMPERATURES SHOULD BE SIMILAR TO WEEKEND MAX
TEMPERATURES.
LONG TERM...TUESDAY THROUGH FRIDAY.
GFS LONG WAVE RIDGE CURRENTLY OVER WESTERN GREENLAND FORECAST TO
SHIFT TO THE EAST COAST OF CANADA THROUGH THE EXTENDED PERIOD. ALSO
LONG WAVE RIDGE FORECAST TO INTENSIFY OVER THE NORTHERN PLAINS THIS
PERIOD.
UPPER LEVEL RIDGE FORECAST TO INTENSIFY OVER THE PLAINS THIS PERIOD
WITH UPPER LEVEL RIDGE AXIS TO SHIFT EAST OF THE AREA LATE THU OR
FRI TIME FRAME. PRECIPITATION MORE LIKELY THEREAFTER. MODELS ARE
VACILLATING BETWEEN RUNS AND SO HAVE TRIMMED BACK POPS ON TUE
THROUGH WED NIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
ROGERS/VOELKER
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1020 AM EDT SAT JUN 2 2012
.SYNOPSIS...
COOL...DRY AIR REMAINS IN PLACE...WITH MID AND UPPER DISTURBANCES
LINGERING THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
NO CHANGES THIS MORNING WITH THE EXCEPTION OF KNOCKING THE SLIGHT
CHANCE BACK A COUPLE HOURS AND SOME SKY GRID TWEAKS. GRIDS IN
GOOD SHAPE OTHERWISE.
PREVIOUS DISCUSSION...
BROAD UPPER LEVEL TROUGH AXIS CROSSES TODAY. AREA REMAINS IN NW
FLOW ALOFT THROUGH TONIGHT WHILE SURFACE FLOW REMAINS W TO SW.
USED RUC ALGORITHM TO MIX DOWN GUSTS TO 20 TO 25 MPH THIS
AFTERNOON. SMALLER DISTURBANCES WITHIN THE LARGER TROUGH ARE HARDER
TO PICK OUT. IT LOOKS LIKE ONE OVER EASTERN OHIO EARLY THIS
MORNING IS PRODUCING NOTHING MORE THAN MID / HI CLOUD...AND IS
DESTINED FOR WESTERN PA. ANOTHER IS MORE EASILY EVIDENT OVER THE
MIDWEST...WHERE SPOTTY LIGHT RADAR ENERGY IS BEING RETURNED. THIS
ONE CROSSES SOUTHERN PORTIONS OF THE AREA THIS EVENING.
OTHERWISE THE NAM12 SEEMS TO HINT AT AN AXIS OF ENHANCED MOISTURE
AND INSTABILITY ACROSS NORTHERN PORTIONS OF THE FORECAST AREA LATER
THIS AFTERNOON. IT MAKES SENSE THAT THE HEATING OF THE EARLY JUNE
DAY BENEATH THE COOL AIR ALOFT SHOULD RESULT IN CONVECTION THIS
AFTERNOON...WITH THE HIGHEST CHANCE N WHERE HEIGHTS / TEMPERATURES
ALOFT ARE LOWEST.
FINALLY...LEANED TOWARD NAM12 ON CLOUDS TONIGHT WHICH SUGGESTS MORE
CLOUDS S AND PERHAPS LESS N WITH A DRY INTRUSION WORKING IN THERE
FROM THE W. EITHER WAY...SHOULD BE JUST ENOUGH CLOUD AND FLOW TO
PRECLUDE FOG AGAIN TONIGHT...ALTHOUGH LITTLE NERVOUS ABOUT CENTRAL
KY WITH 6 SM BR ON CLEARING DESPITE 5 KTS OF WIND. DO HAVE THE
ADDITIONAL DAY OF DRYING TODAY THOUGH.
BLENDED IN THE ADJMET 50/50 WITH PREVIOUS FCST FOR HIGHS TODAY AND
ONLY 25/50 FOR LOWS TONIGHT...SLIGHTLY HIGHER VALUES ESPECIALLY
TODAY.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
WEAK RIDGING ON SUNDAY WILL GIVE WAY TO ANOTHER DISTURBANCE
MAKING ITS WAY TOWARDS THE REGION BY SUNDAY NIGHT. THIS SYSTEM
HOWEVER WILL TRACK JUST TO OUR SOUTH DURING THE DAY ON MONDAY AND
EXITS MONDAY NIGHT...BUT MOISTURE WILL KEEP POPS IN THE FORECAST
AS IT DOES. YET ANOTHER SYSTEM MOVES ACROSS ON TUESDAY AND EXITS
ON TUESDAY NIGHT...KEEPING POPS IN THE FORECAST. TEMPERATURES WILL
BE COOLER THROUGHOUT WITH CLOUDS AND PRECIP AROUND.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THE EXTENDED WILL FEATURE A BLOCKING TYPE PATTERN WITH UPR LOW/TROF
ACROSS NE CONUS AND STOUT RIDGING ACROSS THE PLAINS. THIS KEEPS AREA
IN NW FLOW AND AT MERCY OF ANY DISTURBANCES ROTATING DOWN. MDLS ARE
STRUGGLING WITH TIMING AND PLACEMENT OF ANY DISTURBANCE COMING DOWN
THRU TROF. OTHERWISE...EXPECT MAINLY DRY AND SEASONABLE CONDITIONS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCU IN THE MOUNTAINS...SOME OF IT BELOW 2 KFT...WILL LIFT
INTO VFR LATER THIS MORNING AS IT ALSO REDEVELOPS ACROSS THE
LOWLANDS. COULD NOT RULE OUT BRIEF MVFR MORNING CU BACK ACROSS THE
LOWLANDS BUT PROBABLY NOT AS FAR W AS THE OHIO RIVER. EXPECT THE
CIGS TO STAY VFR TONIGHT.
SCATTERED SHOWERS WILL POP UP THIS AFTERNOON ON THE HEATING OF THE
DAY AND WEAK DISTURBANCES ALOFT. AN EVENING THUNDERSHOWER CANNOT BE
RULED OUT IN SE OHIO OR NRN WV. ANY SHOWER OR THUNDERSHOWER OVER AN
AIRPORT WILL BRING AT WORST BRIEF MVFR CIGS AND VSBYS. THIS
ACTIVITY WILL DISSIPATE AFTER SUNSET TONIGHT.
W TO SW SFC FLOW GUSTY AT TIMES ESPECIALLY MIDDAY AND AFTERNOON
TODAY WHILE FLOW ALOFT REMAINS MODERATE AND MAINLY FROM THE W.
THERE SHOULD BE ENOUGH CLOUD AND WIND TO AGAIN PRECLUDE FOG TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF STRATOCUMULUS CEILINGS
COULD VARY...AS CAN THAT OF SHOWERS THIS AFTERNOON AND EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M M H H H H H H H H H
EKN CONSISTENCY M M M H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY M H H H H H H H H H H H
AFTER 12Z SUNDAY...
NO WIDESPREAD IFR EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/TRM
NEAR TERM...TRM/26
SHORT TERM...JS
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
604 AM EDT SAT JUN 2 2012
.SYNOPSIS...
COOL...DRY AIR REMAINS IN PLACE...WITH MID AND UPPER DISTURBANCES
LINGERING THROUGH AT LEAST THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
BROAD UPPER LEVEL TROUGH AXIS CROSSES TODAY. AREA REMAINS IN NW
FLOW ALOFT THROUGH TONIGHT WHILE SURFACE FLOW REMAINS W TO SW.
USED RUC ALGORITHM TO MIX DOWN GUSTS TO 20 TO 25 MPH THIS
AFTERNOON. SMALLER DISTURBANCES WITHIN THE LARGER TROUGH ARE HARDER
TO PICK OUT. IT LOOKS LIKE ONE OVER EASTERN OHIO EARLY THIS
MORNING IS PRODUCING NOTHING MORE THAN MID / HI CLOUD...AND IS
DESTINED FOR WESTERN PA. ANOTHER IS MORE EASILY EVIDENT OVER THE
MIDWEST...WHERE SPOTTY LIGHT RADAR ENERGY IS BEING RETURNED. THIS
ONE CROSSES SOUTHERN PORTIONS OF THE AREA THIS EVENING.
OTHERWISE THE NAM12 SEEMS TO HINT AT AN AXIS OF ENHANCED MOISTURE
AND INSTABILITY ACROSS NORTHERN PORTIONS OF THE FORECAST AREA LATER
THIS AFTERNOON. IT MAKES SENSE THAT THE HEATING OF THE EARLY JUNE
DAY BENEATH THE COOL AIR ALOFT SHOULD RESULT IN CONVECTION THIS
AFTERNOON...WITH THE HIGHEST CHANCE N WHERE HEIGHTS / TEMPERATURES
ALOFT ARE LOWEST.
FINALLY...LEANED TOWARD NAM12 ON CLOUDS TONIGHT WHICH SUGGESTS MORE
CLOUDS S AND PERHAPS LESS N WITH A DRY INTRUSION WORKING IN THERE
FROM THE W. EITHER WAY...SHOULD BE JUST ENOUGH CLOUD AND FLOW TO
PRECLUDE FOG AGAIN TONIGHT...ALTHOUGH LITTLE NERVOUS ABOUT CENTRAL
KY WITH 6 SM BR ON CLEARING DESPITE 5 KTS OF WIND. DO HAVE THE
ADDITIONAL DAY OF DRYING TODAY THOUGH.
BLENDED IN THE ADJMET 50/50 WITH PREVIOUS FCST FOR HIGHS TODAY AND
ONLY 25/50 FOR LOWS TONIGHT...SLIGHTLY HIGHER VALUES ESPECIALLY
TODAY.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY NIGHT/...
WEAK RIDGING ON SUNDAY WILL GIVE WAY TO ANOTHER DISTURBANCE
MAKING ITS WAY TOWARDS THE REGION BY SUNDAY NIGHT. THIS SYSTEM
HOWEVER WILL TRACK JUST TO OUR SOUTH DURING THE DAY ON MONDAY AND
EXITS MONDAY NIGHT...BUT MOISTURE WILL KEEP POPS IN THE FORECAST
AS IT DOES. YET ANOTHER SYSTEM MOVES ACROSS ON TUESDAY AND EXITS
ON TUESDAY NIGHT...KEEPING POPS IN THE FORECAST. TEMPERATURES WILL
BE COOLER THROUGHOUT WITH CLOUDS AND PRECIP AROUND.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
THE EXTENDED WILL FEATURE A BLOCKING TYPE PATTERN WITH UPR LOW/TROF
ACROSS NE CONUS AND STOUT RIDGING ACROSS THE PLAINS. THIS KEEPS AREA
IN NW FLOW AND AT MERCY OF ANY DISTURBANCES ROTATING DOWN. MDLS ARE
STRUGGLING WITH TIMING AND PLACEMENT OF ANY DISTURBANCE COMING DOWN
THRU TROF. OTHERWISE...EXPECT MAINLY DRY AND SEASONABLE CONDITIONS.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
MVFR STRATOCU IN THE MOUNTAINS...SOME OF IT BELOW 2 KFT...WILL LIFT
INTO VFR LATER THIS MORNING AS IT ALSO REDEVELOPS ACROSS THE
LOWLANDS. COULD NOT RULE OUT BRIEF MVFR MORNING CU BACK ACROSS THE
LOWLANDS BUT PROBABLY NOT AS FAR W AS THE OHIO RIVER. EXPECT THE
CIGS TO STAY VFR TONIGHT.
SCATTERED SHOWERS WILL POP UP THIS AFTERNOON ON THE HEATING OF THE
DAY AND WEAK DISTURBANCES ALOFT. AN EVENING THUNDERSHOWER CANNOT BE
RULED OUT IN SE OHIO OR NRN WV. ANY SHOWER OR THUNDERSHOWER OVER AN
AIRPORT WILL BRING AT WORST BRIEF MVFR CIGS AND VSBYS. THIS
ACTIVITY WILL DISSIPATE AFTER SUNSET TONIGHT.
W TO SW SFC FLOW GUSTY AT TIMES ESPECIALLY MIDDAY AND AFTERNOON
TODAY WHILE FLOW ALOFT REMAINS MODERATE AND MAINLY FROM THE W.
THERE SHOULD BE ENOUGH CLOUD AND WIND TO AGAIN PRECLUDE FOG TONIGHT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SUNDAY...
FORECAST CONFIDENCE: HIGH.
ALTERNATE SCENARIOS: TIMING AND PLACEMENT OF STRATOCUMULUS CEILINGS
COULD VARY...AS CAN THAT OF SHOWERS THIS AFTERNOON AND EVENING.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 06/02/12
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H M M M M H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H M M M M M M M M H
EKN CONSISTENCY H H H H H M H H H H H H
PKB CONSISTENCY M H H H H H H H H H H H
CKB CONSISTENCY M M M M M M M H H H H H
AFTER 12Z SUNDAY...
NO WIDESPREAD IFR EXPECTED AT THIS TIME.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...JS/TRM
NEAR TERM...TRM
SHORT TERM...JS
LONG TERM...30
AVIATION...TRM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
641 AM CDT SAT JUN 2 2012
UPDATED AVIATION PORTION FOR 12Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVING OVER LAKE HURON. LAST PIECE OF
ENERGY NOW SEEN ROTATING BACK TO THE WEST...NORTH OF THE
LOW...PUSHING CLOUDS AND PCPN BACK TOWARDS NORTHEAST WI. WHERE
CLOUDS REMAIN...OR MOVE INTO...THE TEMPERATURES ARE IN THE 40S OR
LOWER 50S. UNDER CLEAR SKIES OVER CENTRAL AND NORTH CENTRAL WI
TEMPS HAVE FALLEN OFF INTO THE 30S. SMALL PCPN CHANCES TODAY
REMAIN THE MAIN FORECAST CONCERN THIS PERIOD.
STACKED LOW TO LIFT SLOWLY NORTH THROUGH SUN MORNING...DEEPENING
SLIGHTLY THROUGH EARLY THIS MORNING. GIVEN PCPN TRENDS AT THIS
TIME...WILL KEEP SCATTERED POPS GOING...FAR NE AND DOOR COUNTY
THROUGH THIS MORNING...BACKING OFF THIS AFTERNOON AS LOWS
INFLUENCE DIMINISHES. AS IN PAST DAYS...MODELS SHOWING GOOD
INSTABILITY THIS AFTERNOON AND HINT AT WEAK SFC TROF/MOISTURE
CONVERGENCE MOVING OVER CWA THIS AFTERNOON. PROBLEM WITH THIS
FORECAST IS AMOUNT OF DRY AIR...WITH SOUNDINGS SHOWING RATHER DEEP
MIXING FOR GUSTY WEST WINDS AND DEW POINTS DROPPING INTO UPPER
30S TO LOWER 40S. THIS WOULD LIMIT ANY SB INSTABILITY. WILL STAY
WITH MAINLY ISOLD POPS AND LIMIT THUNDER TO SOUTH.
HEIGHTS TO RISE AS RIDGE TO WEST BUILDS IN SATURDAY NIGHT AND
SUNDAY WITH DRY FORECAST EXPECTED.
HAVE HELD TEMPS TO NEAR NORMAL LEVELS TODAY WITH CLOUDS...THOUGH
RETURNING TO ABOVE NORMAL HIGHS ON SUN.
.LONG TERM...SUNDAY NGT THRU NXT FRI. MAIN FCST CONCERN REMAINS
THE EXTENT OF PCPN DURING THE PERIOD AND TRYING TO ATTEMPT TO
ASCERTAIN EXACTLY WHICH DAYS TO FOCUS ON. ANY PCPN APPEARS TO BE
RELATIVELY LIGHT AND SCATTERED AT BEST. TEMPS ARE NOT EXPECTED TO
CHANGE MUCH NXT WEEK WITH READINGS GENERALLY CLOSE TO NORMAL.
MDLS CONT TO INDICATE A MID-LVL PIECE OF SHORTWAVE ENERGY MOVING
THRU THE CNTRL CONUS UPR RDG...THEN DIVING SE THRU THE UPR MS
VALLEY AND INTO THE WRN GREAT LKS/MIDWEST SUNDAY NGT. THERE
APPEARS TO BE A QUASI-STNRY BOUNDARY SITUATED FROM MN S-SE INTO IA
AND THIS BOUNDARY COULD HELP FOCUS THE SHWR POTENTIAL MORE TO OUR
SW IN THE CONVERGENCE ZONE. THIS FEATURE IS NOW A LITTLE SLOWER
THAN LAST NGT`S MDL RUNS...THUS HAVE FOCUSED ANY PCPN TIL AFTER
MIDNIGHT AND PRIMARILY OVER CNTRL WI. THIS DELAY IN PCPN COULD
ALLOW FOR TEMPS TO DROP A COUPLE OF MORE DEGS THAN ORIGINALLY
THOUGHT WITH READINGS AROUND 50 NORTH TO THE MIDDLE 50S CNTRL/
E-CNTRL WI.
WHILE THE SHORTWAVE CONTS TO TREK SE TOWARD THE OHIO RIVER VALLEY
ON MON...THE MDLS SHOW A SHORTWAVE TROF ROTATING SWD THRU THE
GREAT LKS AROUND THE LARGE ERN CONUS UPR TROF. THE COMBINATION OF
THIS TROF WITH DAYTIME HEATING (INCREASING INSTABILITY) WL HELP TO
DEVELOP SOME SHWR ACTIVITY ALONG WITH AN ISOLATED TSTM. MAX TEMPS
WL BE DEPENDENT ON HOW FAST ANY PCPN CAN DEVELOP...THUS READINGS
COULD TOP OUT ANYWHERE IN THE 70S.
THE LOSS OF DAYTIME HEATING AND THE DEPARTURE OF THE SHORTWAVE
TROF WL END ANY LINGERING SHWR THREAT MON EVENING. OTHERWISE...AN
AREA OF CANADIAN HI PRES IS FCST TO BEGIN DROPPING SOUTH INTO THE
GREAT LKS LATER MON NGT BRINGING PARTLY CLOUDY SKIES AND SLIGHTLY
COOLER CONDITIONS. WE WL SEE MIN TEMPS RANGE FROM THE UPR 40S TO
THE MID 50S E-CNTRL WI.
THE HIGHLY AMPLIFIED FLOW ACROSS THE CONUS REMAINS INTACT THRU THE
MIDDLE OF NXT WEEK WITH DEEP UPR TROFS OVER THE WRN U.S./ERN U.S.
AND A NARROW UPR RDG OVER THE MIDDLE OF THE COUNTRY. NE WI TO
RESIDE ON THE ERN SIDE OF THE RDG...BUT ALSO SIT ON THE WRN FLANK
OF THE ERN U.S. UPR TROF. THIS LEAVES THE FCST AREA VULNERABLE TO
ADDITIONAL SHORTWAVE TROFS OR INDIVIDUAL SHORTWAVES MOVING THRU
THE BADGER STATE AND KICKING OFF A FEW SHWRS...ESPECIALLY DURING
THE PEAK HEATING OF THE AFTERNOON. THIS SCENARIO WOULD RUN FROM
TUE THRU AT LEAST THU BEFORE THE UPR RDG SLIDES FAR ENUF EAST TO
POTENTIALLY CAP THE ATMOSPHERE BY THE TIME FRI ROLLS AROUND. DUE
TO THE GENERAL UNCERTAINTY IN TRYING TO TIME EACH OF THESE LITTLE
WEATHER ELEMENTS...HAVE FOLLOWED THE CONSENSUS MDL SOLUTION WHICH
POINTS TO LOW CHC POPS MAINLY DURING THE DAYLIGHT HOURS. AS FOR
TEMPS...READINGS SHOULD BE FAIRLY CONSISTENT DUE TO LITTLE CHANGE
IN AIR MASS. LOOK FOR TEMPS TO END UP CLOSE TO CLIMATOLOGICAL
NORMALS NXT WEEK.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH SATURDAY EVENING.
DEEPER MOISTURE AND UPPER LEVEL DISTURBANCES ROTATING AROUND A
GREAT LAKES UPPER LOW WILL BRING SOME SHOWERS TO FAR NE WI...
ESPECIALLY DOOR COUNTY...THROUGH SATURDAY EVENING. GUSTY WEST
WINDS TO AROUND 25 KTS EXPECTED TODAY WITH DEEP MIXING. SOME
INSTABILITY FOR SHOWER CHANCES THIS AFTERNOON...AND HAVE ADDED
VCSH FOR AUW/CWA/GRB/ATW.
TE
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER CO
216 PM MDT SAT JUN 2 2012
...CORRECTION FOR A FEW TYPOS IN 1ST PARAGRAPH...
.SHORT TERM...WEAK QG ASCENT OVER CENTRAL AND EASTERN COLORADO AT
THIS HOUR AHEAD OF A 500MB SHORTWAVE TROUGH PASSING OVER WESTERN
COLORADO. SCATTERED T-STORMS IN THE HIGH COUNTRY HAVE BEGUN TO
MOVE OUT ONTO THE NEARBY PLAINS. CAPES AND LAPSE RATES NOT ALL THAT
GREAT IN THE HIGH COUNTRY AT THIS HOUR UNDER THE HEAVY CLOUD COVER.
ON THE PLAINS...ACCORDING TO THE RUC AND LAPS SFC BASED CAPES IN THE
300-600 J/KG RANGE WITHIN THE I-25 CORRIDOR UNDER INCREASING
MID-LEVEL CLOUD COVER. FARTHER OUT ON THE PLAINS WHERE SKIES WERE
STILL MOSTLY SUNNY...CAPES IN THE 700-1500 J/KG RANGE.
DURING THE NEXT FEW HOURS...SCATTERED T-STORMS MOVING ACROSS THE
I-25 CORRIDOR WILL MOVE OUT ONTO THE PLAINS WHERE THEY/LL LIKELY
MERGE INTO A NEARLY SOLID NORTH-SOUTH LINE OF STORMS. COULD SEE A
FEW STORMS EAST OF I-25 AND SOUTH OF I-76 BECOMING SEVERE EVEN WITH
SFC DEW POINTS ONLY IN THE 40S. VERTICAL SHEAR NOT ALL THAT GREAT
TODAY...SO THREAT OF TORNADOES IS QUITE LOW. HOWEVER CAN/T RULE OUT
A BRIEF WEAK TORNADO/LANDSPOUT ALONG AN OUTFLOW BOUNDARY. MAY EVEN
SEE ONE AS CLOSE AS D.I.A. ACARS SOUNDING AT DENVER AS OF 19Z DRY
ADIABATIC BELOW 500MB WITH A LARGE SUB-CLOUD TEMP/DEW POINT SPREAD.
IT/S LOOKING FAR LESS LIKELY WE/LL SEE ANY HAIL INSIDE THE I-25
CORRIDOR WITH FREEZE LEVEL CURRENTLY UP AROUND 15 THSND FT MSL.
BIGGEST THREAT WILL BE DAMAGING MICROBURST WINDS WITH POTENTIAL
GUSTS TO AROUND 50KTS. HAIL TO AROUND 1 INCH ALSO POSSIBLE ROUGHLY
SOUTHEAST OF AN AKRON-TO-ELBERT LINE AFTER 21Z TODAY...WITH EVEN
LARGER STONES WITH MERGING STORM CELLS.
THIS STORM FRONT IS EXPECTED TO MOVE EAST OF AN AKRON-TO-LIMON
LINE BY MID-LEVEL WITH THE PASSING TROUGH AXIS. SHOULD SEE STEADY
DRYING AND CLEARING FROM WEST-TO-EAST DURING THE EVENING HOURS
WITH INCREASING SUBSIDENCE IN THE WAVE OF THE TROUGH.
ON SUNDAY...WILL SEE MID-LEVEL DRYING AND WARMING WITH AN UPPER
RIDGE MOVING IN FROM THE GREAT BASIN WITH LIGHT WEST-NORTHWEST
FLOW OVER THE AREA MUCH OF THE DAY. ON THE PLAINS...WEAK
NORTHERLY SFC WINDS GRADUALLY TURN NORTHEASTERLY ACCORDING TO
MODELS BY MIDDAY WHICH APPEARS TO GENERATE A FAIR AMOUNT OF MID-
LEVEL CLOUDINESS ALONG THE FRONT RANGE BY AFTERNOON...WITH
POSSIBLY A FEW SHOWERS/ T-STORMS OVER AND NEAR THE FOOTHILLS
LATER IN THE AFTERNOON. STILL LOOKS QUITE WARM ON SUNDAY WITH MAX
TEMPERATURES IN THE UPPER 80S AND LOWER 90S ON THE PLAINS BEFORE
CLOUDS DEVELOP. DO NOT SEE MUCH IN THE WAY OF PCPN IF ANY IN THE
HIGH COUNTRY WHERE ATMOSPHERE WILL BE DRIER.
.LONG TERM....LONG TERM...A DEEP UPPER LEVEL TROUGH WILL BE OVER
THE PACIFIC NORTHWEST WHILE A RIDGE RESIDES OVER THE CENTRAL PART
OF THE COUNTRY DURING THE EARLY PART OF NEXT WEEK. MODELS ARE IN
GOOD AGREEMENT WITH THIS AND THEN HAVING THE TROUGH LIFT NORTH
INTO CANADA BY THURSDAY. FOR COLORADO...THERE ARE DIFFERENCE WITH
THE DETAILS. THE TIMING OF SHORT WAVES AND THE AMOUNT OF MOISTURE
DIFFER FOR NEXT WEEK. WILL CONTINUE WITH THE ABOVE NORMAL
TEMPERATURES AND BROAD BRUSH OF LOW POPS FOR NEXT WEEK. WOULD
EXPECT A DAY OR TWO OF INCREASED CONVECTION AS WEAK SHORT WAVE
TROUGHS MOVE OVER THE AREA.
BY FRIDAY...THE RIDGE OVER CENTRAL U.S. WILL FLATTEN AS THE FLOW
ACROSS THE NORTHERN ROCKIES INCREASES. THIS WILL CAUSE THE FLOW OVER
COLORADO TO BECOME MORE WESTERLY...WHICH MAY BRING FEWER SHOWERS AND
STORMS FOR FRIDAY AND SATURDAY.
&&
.AVIATION...THE CHANCE FOR THUNDERSTORMS WILL INCREASE AT DENVER
AREA AIRPORTS NOW THROUGH 22Z...WITH THE BIGGEST RISK FROM STORMS
BEING STRONG MICROBURST WINDS AND LIGHTNING. COULD BRIEFLY SEE ILS
CEILINGS WITH PRECIPITATION WITH PASSING STORMS. SMALL HAIL ALSO
POSSIBLE IN AREAS EAST OF I-25...POSSIBLY UP TO A HALF INCH IN
DIAMETER. WINDS FROM HIGH BASED T-STORMS COULD GUSTS TO 45KTS
POTENTIALLY CAUSING SERIOUS IMPACT TO AIRPORT OPERATIONS.
THUNDERSTORMS ARE EXPECTED TO MOVE EAST OF THE DENVER METRO AREA
AFTER 00Z THIS EVENING WITH DRIER WINDS FLOWING DOWN OFF THE
FOOTHILLS. BY LATE THIS EVENING...SHOULD SEE THE NORMAL DRAINAGE
WIND PATTERN SET UP UNDER CLEARING SKIES BY 06Z TONIGHT.
&&
.HYDROLOGY...THE RISK FOR FLOODING AT THE FRONT RANGE BURN SCARS
INCLUDING THE FOURMILE BURN SCAR WEST OF BOULDER LOOKS LOW FOR THE
REST OF THIS AFTERNOON. HOWEVER A FEW STORMS MAY STILL PRODUCE
0.25 TO 0.40 OF RAIN IN UNDER 40 MINUTES WHICH MAY CAUSE MINOR
HIGH WATER RUNOFF. RISK OF ANY FLOODING SHOULD COME TO AN END
AFTER 8 PM THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM....MEIER
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS DENVER CO
1018 AM MDT SAT JUN 2 2012
.UPDATE...
&&
.SHORT TERM...RATHER IMPRESSIVE CONVECTION WITH POCKETS OF CG LTG
ALREADY OCCURRING ON THE WEST SLOPE AT THIS HOUR. DEVELOPMENT
ACCOMPANYING THE SHORTWAVE INDUCED CLOUD SHIELD IS MAKING GOOD
EASTWARD PROGRESS AND ITS PRESENT SPEED WE SHOULD SEE LEADING EDGE
OF THICKER CLOUDS SPREADING OVER WESTERN PORTIONS OF THE FCST
AREA DURING THE NEXT HOUR. LATEST RUC IS INDICATING SFC BASED
CAPES IN THE 150-300 J/KG RANGE OVER THE HIGHER ELEVATIONS...INCLUDING
HIGHER REACHES OF THE FRONT RANGE MTNS AT THIS HOUR. CURRENT
CONDITIONS ON THE PLAINS...MOSUNNY SKIES AND SFC DEWPTS GENERALLY
IN THE 40S. IN THE NEXT COUPLE OF HOURS WOULD EXPECT TO SEE
FAIRLY RAPID CONVECTIVE INITIATION OVER THE FRONT RANGE AND
T-STORM FORMATION BEFORE THE NOON HOUR. HRRR AND 12Z/NAM COMPOSITE
REFLECTIVITY FIELDS INDICATE MULTI-CELL STORM DEVELOPMENT OVER THE
FRONT RANGE FOOTHILLS AT OR ABOUT 18Z TODAY. FROM THERE MODEL
DERIVED REFLECT IVITIES DRIFT EAST ACROSS THE I-25 URBAN CORRIDOR
THROUGH WHAT APPEARS TO BE A LESS THAN FAVORABLE ENVIRONMENT FOR
STRONG STORM GROWTH...I.E. CAPES LESS THAN 1000 J/KG AND DEWPTS
IN THE UPPER 30S TO MID 40S. HOWEVER MODEL SOUNDINGS INDICATE A
MODERATE TO HIGH POTENTIAL FOR STRONG/DAMAGING MICROBURST WINDS
WITH THIS LEADING WAVE OF STORMS MOVING OFF THE FRONT RANGE. ALSO
CAN NOT RULE SMALL HAIL EVEN WITH THE FREEZE LEVEL ABOVE 14000 FT
MSL. IT/S JUST EAST OF THE I-25 URBAN CORRIDOR/EAST-SOUTHEAST OF
THE DENVER METRO AREA/THAT THE CHANCE FOR SEVERE T-STORMS APPEARS
GREATER. SUSPECT WE/LL SEE THE LINE OF STORMS MOVING ACROSS THE
URBAN CORRIDOR INTENSIFYING AS THEY PUSH IN HIGHER DEWPTS AND
BNDRY LAYER CAPES IN THE 1100-1900 J/KG SOMETIME AROUND 20-21Z.
ASSUMING IT DOESN/T CLOUD OVER TOO QUICKLY...COULD SEE A FEW
SEVERE STORMS EMBEDDED IN A NORTH-SOUTH LINE OF NON-SEVERE STORMS
MOVING EAST ACROSS THE PLAINS DURING THE MID AND LATE AFTERNOON
HOURS. COULD SEE A COUPLE STORMS PRODUCING HAIL UP TO AN INCH OR
SO IN THE HIGHER DEWPTS ROUGHLY EAST OF DENVER AND SOUTH OF I-76.
WHERE DO NOT SEE MUCH SHEAR TODAY WITH RELATIVELY WEAK WESTERLY
FLOW ALOFT AND LIGHT SOUTH-SOUTHEAST FLOW AT THE SFC. BUT
LOCALIZED SHEAR COUPLETS ALONG THE ADVANCING T-STORM GUST FRONT
COULD SPIN UP A BRIEF TORNADO/LANDSPOUT OR TWO. MAY EVEN SEE ONE
POP UP NEAR THE EAST SIDE OF THE DENVER METRO AREA. WITH THE
SHORTWAVE EXITING THE AREA BY LATE THIS EVENING...THERE/S NOT MUCH
ELSE TO KEEP T-STORMS GOING...SO CLEARING AFTER MIDNIGHT.
BOTTOM LINE...DOES NOT LOOK LIKE A BIG SEVERE WEATHER DAY FOR US...BUT
WOULDN/T BE SURPRISED IF SPC PUTS OUT A SVR T-STORM WATCH FOR
PORTIONS OF EASTERN COLORADO LATER TODAY.
.AVIATION...VFR CONDITIONS IN THE DENVER AREA AT THIS HOUR...COULD
BRIEFLY GO MVFR WITH PASSING LINE OF THUNDERSTORMS MOVING OFF THE
FRONT RANGE AND ACROSS THE DENVER METRO AREA...ESTIMATING BETWEEN
1930-2130Z THIS AFTERNOON. STRONG AND VERY GUSTY OUTFLOW WINDS
PRODUCED BY THESE STORMS BIGGEST CONCERN FOR OPERATIONS AT DENVER
AREA AIRPORTS. FREQUENT CLOUD-TO-GROUND LIGHTNING ALSO A BIG
CONCERN. MAY SEE SOME SMALL HAIL WITH STORMS ON THE EAST SIDE OF
THE METRO AREA...BUT THE LARGER HAIL SHOULD FALL EAST OF THE METRO
AREA. FURTHERMORE...THERE IS A SLIGHT CHANCE THAT A BRIEF WEAK
TORNADO OR LANDSPOUT COULD FORM ALONG ONE OF THE T-STORM OUTFLOW
BOUNDARIES EAST OF I-25. CONDITIONS SHOULD QUICKLY IMPROVE LATE
AFTERNOON AND/OR EARLY EVENING WITH THE UPPER AIR DISTURBANCE
PRODUCING THIS CONVECTION MOVES EAST OF THE AREA.
&&
.HYDROLOGY...THUNDERSTORMS FORMING UP ALONG THE CONTINENTAL DIVIDE
IN THE NEXT 203 HOURS ARE EXPECTED TO MOVE DOWN ACROSS THE FRONT
RANGE FOOTHILLS DURING THE EARLY AFTERNOON HOURS AT 15-25 KTS. A
FEW OF THESE STORMS COULD PRODUCE 0.30 TO 0.45 INCH OF RAIN IN
UNDER 45 MINUTES...ALONG WITH SOME SMALL HAIL. THE THREAT FOR
FLOODING WITHIN THE FOURMILE BURN SCAR APPEARS LOW TODAY.
HOWEVER...WOULD NOT RULE OUT MINOR RUNOFF IN BARE SURFACE AREAS.
&&
.PREV DISCUSSION... /ISSUED 314 AM MDT SAT JUN 2 2012/
SHORT TERM...A WEAK SHORTWAVE WILL MOVE ACROSS THE AREA
TODAY...BRINGING LIFT TO THE MOUNTAINS AROUND MIDDAY AND THE
PLAINS THIS AFTERNOON. THE AIRMASS AHEAD OF THIS TROUGH WILL BE
SLIGHTLY WARMER AND MOISTER THAN YESTERDAY...RESULTING IN MORE
ENERGY FOR CONVECTION. THERE ARE MINOR DIFFERENCES IN THE MOISTURE
IN THE MODELS...GFS IS MOISTER AND LOOKS A BIT TOO RICH WITH 50
DEW POINTS NEAR THE EASTERN BORDER. BUT A CONSENSUS SEEMS FINE
WITH DEW POINTS IN THE 40S. THIS WILL GIVE CAPES OF 1200-2000 J/KG
THIS AFTERNOON DEPENDING ON HOW MUCH HEATING OCCURS BEFORE CLOUD
COVER DEVELOPS. THE TIMING IS A BIT FASTER THAN OPTIMAL...AND THE
CLOUD COVER WILL LIKELY ALSO LIMIT DEVELOPMENT TO OUTFLOW
BOUNDARIES AFTER THE INITIAL CONVECTION GETS GOING. SHEAR IS ALSO
LIMITED...0-6 KM SHEAR OF 20-30 KNOTS...SO MULTICELL OR LINEAR
STRUCTURES ARE THE LIKELY MODE. STILL ENOUGH CAPE/SHEAR TO SUPPORT
HAIL AND SOME WIND THREAT AS WELL. MAYBE SOME HELICITY TO WORK
WITH OUT ON THE PLAINS BY THE END OF THE AFTERNOON...BUT NOT
LOOKING LIKE TOO MUCH OF A TORNADO THREAT.
EXPECT EVERYTHING TO BE EARLIER THAN OUR NORMAL CONVECTIVE
SCHEDULE...WITH MOUNTAIN CONVECTION DEVELOPING BY LATE MORNING AND
CONSOLIDATING ON THE OUTFLOW BOUNDARIES ONTO THE PLAINS BY MID
AFTERNOON. BETWEEN CLOUDS FROM THE EARLY CONVECTION AND THE TIME
OF DAY...THIS LEAVES A CHANCE FOR THE FRONT RANGE CITIES TO GET
SKIPPED OVER SO I WILL NOT RAISE POPS TOO MUCH...BUT WILL GO AHEAD
AND MENTION THE SEVERE THREAT WITH THE STRONGER STORMS.
EXPECT THAT THERE MAY NOT BE MUCH ACTIVITY BEHIND THE TROUGH...SO
WENT WITH LOWER EVENING POPS AND GOOD CLEARING BY MORNING. TEMPS
MAY BE A LITTLE HIGH TODAY AND A BIT TOO LOW TONIGHT IF THERE IS
MORE CLOUD COVER THAN EXPECTED...BUT FOR NOW I LEFT THEM ALONE.
LONG TERM...MODELS STILL INDICATE AN UNSETTLED WEEK OF WEATHER
AHEAD OF US AS A WEAK UPPER LEVEL RIDGE REMAINS OVER THE ROCKY
MOUNTAINS AND GRADUALLY AMPLIFIES. THE GFS AND ECMWF HAVE SIMILAR
SOLUTIONS WITH RESPECT TO THE UPPER RIDGE OVER COLORADO...BUT THEY
DIFFER ON THE STRENGTH AND POSITIONING OF THE UPSTREAM TROUGH OVER
THE PACIFIC NORTHWEST AND NORTHERN GREAT BASIN. THE ECMWF
CONTINUES BRINGING THE UPPER TROUGH/LOW INTO SOUTHERN IDAHO BY
NEXT WEDNESDAY MORNING WHILE THE GFS KEEP UPPER DISTURBANCE OVER
NORTHEAST OREGON AND WASHINGTON. THE ECMWF SOLUTION WILL BRING
STRONGER SOUTHWEST FLOW ALOFT INTO NORTHWEST AND NORTH CENTRAL
COLORADO. ALONG WITH THE WEAK UPPER RIDGE IN THE HEIGHT FIELD...
WARM TEMPERATURES AT LOW LEVELS WILL PRODUCE A THERMAL TROUGH
WHICH WILL TRANSLATE TO PERSISTENT LOW SURFACE PRESSURE OVER THE
MOUNTAINS. BY MONDAY THIS PATTERN WILL BEGIN DRAWING MOISTURE
NORTHWARD FROM THE SOUTHERN PLAINS. SOUTHERLY FLOW WILL THEN
CONTINUE MOST OF THE WEEK...BRINGING MOISTURE AND INSTABILITY INTO
EASTERN COLORADO. EACH DAY OF THE WEEK WILL HAVE A CHANCE OF
THUNDERSTORMS DEVELOPING AS THE AMPLIFIED UPPER RIDGE REMAINS IN
PLACE AND ALLOWS GULF MOISTURE TO CONTINUE ADVECTING OVER THE HIGH
PLAINS. THE ECMWF INDICATES THAT THE LATTER HALF OF THE WEEK WILL
BE THE WETTEST SINCE THAT MODEL HOLDS THE UPPER RIDGE AXIS FURTHER
WEST THAN THE GFS. THE GFS BREAKS DOWN THE UPPER RIDGE LATE IN THE
WEEK...BUT WE WILL HAVE TO WAIT TO SEE WHICH SOLUTION PANS OUT.
PREVIOUS FORECAST PACKAGES HAVE ALREADY HAD THE MENTION OF SHOWERS
EACH AFTERNOON AND EVENING THROUGH THE WEEK...SO VERY FEW
ADJUSTMENTS WERE MADE THIS TIME AROUND.
AVIATION...SCATTERED THUNDERSTORMS ARE EXPECTED IN THE DENVER
AREA THIS AFTERNOON. THE MAIN THREAT IS VARIABLE WINDS GUSTING
OVER 30 KNOTS...THOUGH HAIL IS ALSO POSSIBLE WITH A FEW OF THE
STORMS. THE STORMS MAY CONSOLIDATE INTO A LINE OF STRONG
CONVECTION EAST AND SOUTHEAST OF DENVER IN THE LATE AFTERNOON AND
EARLY EVENING.
HYDROLOGY...THERE IS A SMALL THREAT OF FLOODING IN THE FOURMILE
BURN AREA TODAY. IN GENERAL...STORMS WILL BE MOVING AT LEAST 15
MPH WHICH WILL LIMIT THE THREAT...BUT THE STRONGEST STORMS TODAY
COULD PRODUCE AN INCH OF RAIN IN UNDER AN HOUR. THE MAIN TIME OF
THE THREAT IS EARLY AFTERNOON. ELSEWHERE THE THREAT OF FLOODING IS
MINIMAL.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER/GIMMESTAD
LONG TERM....DANKERS
AVIATION...BAKER/GIMMESTAD
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
600 PM CDT SAT JUN 2 2012
...UPDATE TO AVIATION FOR 00Z TAFS...
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CDT SAT JUN 2 2012
SCATTERED HIGH BASED CONVECTION IS DEVELOPING AND INCREASING IN
AREAL COVERAGE ACROSS THE CENTRAL ROCKIES THIS AFTERNOON. THESE
STORMS ARE MODELED BY THE VARIOUS MESOSCALE NUMERICAL MODELS TO
CONGEAL INTO ONE OR TWO SEPARATE MULTICELL MESOSCALE CONVECTIVE
SYSTEMS AND SPREAD INTO WESTERN KANSAS ON THE EVENING. THE AXIS OF
STRONGEST INSTABILITY AND HIGH CAPE IS ORIENTED FROM SOUTHEAST
COLORADO INTO NORTHEAST NEW MEXICO AND THE PANHANDLES. THE TOTAL
CAPES DROPS DRAMATICALLY HEADING EASTWARD TOWARD THE LOWER TERRAIN,
HOWEVER, VERY STEEP LOW LEVEL LAPSE RATES EXTENDING ACROSS MUCH OF
WESTERN KANSAS SHOULD STILL SUPPORT PROLIFIC THUNDERSTORMS GUST
POTENTIAL THOUGH THE EVENING FROM ANY THUNDERSTORM CLUSTERS THAT
BECOME SUSTAINED INTO THE AREA. THE HRRR MODEL BASICALLY DEVELOPED 2
CLUSTERS, ALLOWING THE MAIN WIND THREAT TO BE SPLIT TO THE NORTH AND
THE SOUTH OF THE AREA. IN CONTRAST THE VARIOUS WRF RUNS PRODUCE
MORE OF A SINGLE LARGER CLUSTER CENTERING TOWARD HAMILTON AND
STANTON COUNTIES BY VERY LATE AFTERNOON.
THE MODELS ALSO INDICATE AN EMBEDDED MID LEVEL SHORT WAVE/PV
ANOMALY MOVING INTO WESTERN KANSAS DURING THE EVENING. THE
LOCALIZED MESOSCALE LIFT FROM SUCH A FEATURE SHOULD SUPPORT
CONVECTION FARTHER EAST INTO CENTRAL KANSAS DURING THE EVENING HOURS
IN A MUCH WEAKENED MOST UNSTABLE CAPE ENVIRONMENT. WITH THIS
IMPULSE MOVING THOUGH THE AREA, A SMALL CHANCE OF SHOWERS AND
THUNDERSTORMS WILL STILL BE POSSIBLE THROUGH AROUND 12Z IN THE EARLY
MORNING SUNDAY ACROSS CENTRAL KANSAS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 345 PM CDT SAT JUN 2 2012
AS A COLD FRONT MOVES SOUTH MONDAY NIGHT, IT SHOULD BE ACROSS
SOUTHERN KANSAS BY TUESDAY MORNING, BRINGING A CHANCE FOR
THUNDERSTORMS TO OUR WEST AND SOUTHERN CWA, WITH A MUCH LESS CHANCE
IN THE EAST DUE TO COLD AIR SINKING IN. AN UPPER WAVE THEN DIVES
SOUTHEAST FROM WYOMING INTO KANSAS WEDNESDAY NIGHT AND THURSDAY, AS
THAT FRONT MEANDERS NORTHWARD AS A WARM FRONT. THIS UPPER WAVE
COULD BRING UNSTABLE CONDITIONS TO MOST OF WESTERN KANSAS
WITH NUMEROUS THUNDERSTORMS EXPECTED, AND ALSO THE CHANCE FOR SEVERE
STORMS. THE AREA EAST OF WAKEENEY TO ASHLAND WILL LIKELY HAVE THE
HIGHEST LOW LEVEL MOISTURE, AND THAT AREA IS WHERE SEVERE STORMS
SEEM THE MOST LIKELY WEDNESDAY AND THURSDAY. BY FRIDAY,
THUNDERSTORM CHANCES WILL MOVE EVEN MORE EASTWARD, EAST OF A HAYS TO
MEDICINE LODGE LINE. SATURDAY, MOST OF THE UPPER MOMENTUM WILL HAVE
MOVED SOUTH AND EAST, SO POPS WILL DECREASE TO LESS THAN 15 PERCENT
FOR ALL BUT OUR FAR EASTERN ZONES, MAINLY IN THE SAINT JOHN TO PRATT
AREAS.
TEMPERATURES MONDAY WILL START WITH MAX TEMPERATURES IN THE LOWER
90S, COOL TO THE MID 80S BY WEDNESDAY, AND DROP AS LOW AS THE LOWER
TO MIDDLE 80S BY FRIDAY. A SLIGHT WARM UP WILL OCCUR SATURDAY AS A
DOWN SLOPE WILL DEVELOP FROM THE MID LEVELS DOWNWARD. MINIMUM
TEMPERATURES WILL MAINLY BE IN THE MID 60S THROUGH THE EXTENDED FOR
PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 600 PM CDT SAT JUN 2 2012
FOLLOWED THE HRRR FOR TEMPORAL GUIDANCE WITH CONVECTION ACROSS THE
HIGH PLAINS OF EASTERN COLORADO AS THIS MODEL SEEMS TO BE DOING FAIRLY
WELL IN COMPARING TO ACTUAL WSR-88D TRENDS. THINK THE BIGGEST CONCERN
FOR TAFS IS OUTFLOW WINDS FROM THE THUNDERSTORM COMPLEXES. OTHERWISE,
VFR CIGS WILL PREVAIL THROUGH THE TAF PD.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 93 67 91 / 80 10 10 10
GCK 61 94 66 91 / 80 10 10 10
EHA 60 96 65 90 / 80 20 20 20
LBL 64 96 67 92 / 80 10 20 20
HYS 65 92 67 91 / 50 20 20 10
P28 65 93 69 91 / 40 20 30 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
349 PM CDT SAT JUN 2 2012
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 343 PM CDT SAT JUN 2 2012
SCATTERED HIGH BASED CONVECTION IS DEVELOPING AND INCREASING IN
AREAL COVERAGE ACROSS THE CENTRAL ROCKIES THIS AFTERNOON. THESE
STORMS ARE MODELED BY THE VARIOUS MESOSCALE NUMERICAL MODELS TO
CONGEAL INTO ONE OR TWO SEPARATE MULTICELL MESOSCALE CONVECTIVE
SYSTEMS AND SPREAD INTO WESTERN KANSAS ON THE EVENING. THE AXIS OF
STRONGEST INSTABILITY AND HIGH CAPE IS ORIENTED FROM SOUTHEAST
COLORADO INTO NORTHEAST NEW MEXICO AND THE PANHANDLES. THE TOTAL
CAPES DROPS DRAMATICALLY HEADING EASTWARD TOWARD THE LOWER TERRAIN,
HOWEVER, VERY STEEP LOW LEVEL LAPSE RATES EXTENDING ACROSS MUCH OF
WESTERN KANSAS SHOULD STILL SUPPORT PROLIFIC THUNDERSTORMS GUST
POTENTIAL THOUGH THE EVENING FROM ANY THUNDERSTORM CLUSTERS THAT
BECOME SUSTAINED INTO THE AREA. THE HRRR MODEL BASICALLY DEVELOPED 2
CLUSTERS, ALLOWING THE MAIN WIND THREAT TO BE SPLIT TO THE NORTH AND
THE SOUTH OF THE AREA. IN CONTRAST THE VARIOUS WRF RUNS PRODUCE
MORE OF A SINGLE LARGER CLUSTER CENTERING TOWARD HAMILTON AND
STANTON COUNTIES BY VERY LATE AFTERNOON.
THE MODELS ALSO INDICATE AN EMBEDDED MID LEVEL SHORT WAVE/PV
ANOMALY MOVING INTO WESTERN KANSAS DURING THE EVENING. THE
LOCALIZED MESOSCALE LIFT FROM SUCH A FEATURE SHOULD SUPPORT
CONVECTION FARTHER EAST INTO CENTRAL KANSAS DURING THE EVENING HOURS
IN A MUCH WEAKENED MOST UNSTABLE CAPE ENVIRONMENT. WITH THIS
IMPULSE MOVING THOUGH THE AREA, A SMALL CHANCE OF SHOWERS AND
THUNDERSTORMS WILL STILL BE POSSIBLE THROUGH AROUND 12Z IN THE EARLY
MORNING SUNDAY ACROSS CENTRAL KANSAS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 345 PM CDT SAT JUN 2 2012
AS A COLD FRONT MOVES SOUTH MONDAY NIGHT, IT SHOULD BE ACROSS
SOUTHERN KANSAS BY TUESDAY MORNING, BRINGING A CHANCE FOR
THUNDERSTORMS TO OUR WEST AND SOUTHERN CWA, WITH A MUCH LESS CHANCE
IN THE EAST DUE TO COLD AIR SINKING IN. AN UPPER WAVE THEN DIVES
SOUTHEAST FROM WYOMING INTO KANSAS WEDNESDAY NIGHT AND THURSDAY, AS
THAT FRONT MEANDERS NORTHWARD AS A WARM FRONT. THIS UPPER WAVE
COULD BRING UNSTABLE CONDITIONS TO MOST OF WESTERN KANSAS
WITH NUMEROUS THUNDERSTORMS EXPECTED, AND ALSO THE CHANCE FOR SEVERE
STORMS. THE AREA EAST OF WAKEENEY TO ASHLAND WILL LIKELY HAVE THE
HIGHEST LOW LEVEL MOISTURE, AND THAT AREA IS WHERE SEVERE STORMS
SEEM THE MOST LIKELY WEDNESDAY AND THURSDAY. BY FRIDAY,
THUNDERSTORM CHANCES WILL MOVE EVEN MORE EASTWARD, EAST OF A HAYS TO
MEDICINE LODGE LINE. SATURDAY, MOST OF THE UPPER MOMENTUM WILL HAVE
MOVED SOUTH AND EAST, SO POPS WILL DECREASE TO LESS THAN 15 PERCENT
FOR ALL BUT OUR FAR EASTERN ZONES, MAINLY IN THE SAINT JOHN TO PRATT
AREAS.
TEMPERATURES MONDAY WILL START WITH MAX TEMPERATURES IN THE LOWER
90S, COOL TO THE MID 80S BY WEDNESDAY, AND DROP AS LOW AS THE LOWER
TO MIDDLE 80S BY FRIDAY. A SLIGHT WARM UP WILL OCCUR SATURDAY AS A
DOWN SLOPE WILL DEVELOP FROM THE MID LEVELS DOWNWARD. MINIMUM
TEMPERATURES WILL MAINLY BE IN THE MID 60S THROUGH THE EXTENDED FOR
PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1259 PM CDT SAT JUN 2 2012
A MULTICELL CONVECTIVE COMPLEX WILL DEVELOP ACROSS EASTERN COLORADO
LATE THIS AFTERNOON AND SPREAD RAPIDLY EASTWARD INTO WESTERN KANSAS
DURING THE VERY LATE AFTERNOON AND EARLY EVENING HOURS. THE VARIOUS
MESOSCALE MODELS CONSENSUS INDICATE A HIGH PROBABILITY FOR
WIDESPREAD GUST FRONT SPREADING RAPIDLY EASTWARD THROUGH THE
EVENING, PERHAPS WELL AHEAD OF THE CONVECTION ESPECIALLY AT KDDC.
THE MOST LIKELY SCENARIO WILL BE THE GUST FRONT LOSING MOMENTUM
AND PRODUCING SUB SEVERE WIND SPEEDS BY THE TIME IT REACHES THE
TERMINALS. THE RELATIVELY DRY ATMOSPHERE OVER WESTERN KANSAS
SUGGESTS CLOUD BASES ABOVE 3000 FT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 93 67 91 / 80 10 10 10
GCK 61 94 66 91 / 80 20 10 10
EHA 60 96 65 90 / 80 20 20 20
LBL 64 96 67 92 / 80 10 20 20
HYS 65 92 67 91 / 50 20 20 10
P28 65 93 69 91 / 40 20 30 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 11 PM CDT FOR HAMILTON STANTON AND
MORTON COUNTIES.
&&
$$
SHORT TERM...RUSSELL
LONG TERM...BURKE
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS BILLINGS MT
222 PM MDT SAT JUN 2 2012
.SHORT TERM...VALID FOR SUN AND MON...
THE FORECAST NOW INCLUDES A SEVERE THUNDERSTORM WATCH UNTIL 03 UTC
FOR ALL OF SOUTH CENTRAL AND SOUTHEASTERN MT. SCATTERED STORMS ARE
ON TRACK TO POSE A SEVERE THREAT THE NEXT SEVERAL HOURS. SCHULTZ
PREVIOUS DISCUSSION...ISSUED AT 125 PM MDT SAT JUN 2 2012...
THE POTENTIAL FOR SEVERE WIND OR HAIL THROUGH THIS EVENING REMAINS
THE FOCUS OF THE SHORT TERM. WE ALLOWED CONTINUITY TO RULE MUCH OF
THE SUN AND MON FORECAST...ESPECIALLY SINCE UNCERTAINTY GROWS WITH
REGARD TO STORM CHANCES ON MON.
FOR THE REST OF THIS AFTERNOON AND EVENING...SCATTERED STORMS WILL
AFFECT THE AREA...AND WE HAVE INCLUDED A SEVERE MENTION WITHIN THE
GRIDDED FORECAST EVERYWHERE GIVEN EFFECTIVE BULK SHEAR OF 30 TO 40
KT...MLCAPE OF 500 T0 1000 J/KG WITH STEEP 700-500 HPA LAPSE RATES
AROUND 8 DEG C/KM...AND INVERTED V-SOUNDING PROFILES. WIND WILL BE
THE MAIN THREAT...BUT MARGINALLY SEVERE HAIL IS POSSIBLE TOO. SOME
INITIAL CONVECTION IS MOVING THROUGH SOUTH CENTRAL MT AS OF 19 UTC
AND THAT ACTIVITY COULD STRENGTHEN...OR JUST BECOME MORE EFFECTIVE
AT PRODUCING STRONG WINDS...AS IT MOVES INTO THE DESTABILIZING AIR
MASS FROM SHERIDAN WY UP INTO SOUTHEASTERN MT. MEANWHILE...WE HAVE
HAD A SOLID AREA OF CLEARING BEHIND THE CLOUDS ASSOCIATED WITH THE
INITIAL CONVECTION...SO NEAR-TERM MODEL SOLUTIONS LOOK ON TRACK IN
SHOWING MLCAPE INCREASING QUICKLY THIS AFTERNOON. THE STORMS CLOSE
TO DILLON MT AT 19 UTC WILL BE TRACKING INTO THIS AIR MASS...AND A
SIMPLE EXTRAPOLATION TAKES THAT ACTIVITY INTO LIVINGSTON AROUND 21
UTC AND BILLINGS NEAR 23 UTC. THAT LINES UP WELL WITH COLD FRONTAL
TIMING SHOWN BY MOST MODELS...INCLUDING THE 18 UTC RAP AND 15 UTC
HRRR...WITH PASSAGE AT BILLINGS ADVERTISED AROUND 00 UTC. LOOK FOR
MOST OF THE ACTIVITY TO SETTLE DOWN BY ABOUT 03 UTC...WITH A QUIET
PERIOD FOR MOST OF THE AREA OVERNIGHT.
SUN...A SURFACE HIGH PRESSURE RIDGE WILL SLIDE FROM EASTERN MT AND
INTO THE WESTERN DAKOTAS BENEATH A NEBULOUS WEST-SOUTHWEST 500-HPA
FLOW. LOW-LEVEL EASTERLY FLOW AND 500 J/KG OF MLCAPE COULD SUPPORT
SOME AFTERNOON AND EVENING STORMS IN AND NEAR THE HIGH TERRAIN. WE
CHOSE TO KEEP EVEN LOW CHANCES OF CONVECTION OUT OF BILLINGS UNTIL
AFTER 00 UTC THOUGH BECAUSE FORECAST SOUNDINGS SHOW MINIMAL MLCAPE
AND MODEST CAPPING OVER THAT AREA DURING THE DAY. WE ARE SHOWING A
SLIGHT CHANCE OF STORMS OVER THE PLAINS OF SOUTH CENTRAL MT ON SUN
NIGHT...BUT ONLY A WEAK LOW-LEVEL JET IS SHOWN BY THE LAST SEVERAL
MODEL SIMULATIONS. THUS...THE CONVECTION MAY END UP BEING REMNANTS
OF THE STUFF THAT COMES OFF THE HIGH TERRAIN...RATHER THAN ANY NEW
DEVELOPMENT. THAT MAY RESULT IN MINIMAL COVERAGE AFTER 06 UTC.
MON...LOW-LEVEL SOUTHEAST FLOW IS EXPECTED TO INCREASE AS PRESSURE
FALLS COMMENCE OVER THE REGION. THE 12 UTC NAM /AND MOST PAST RUNS
OF THAT MODEL/ SIMULATES DEEP CONVECTION IN THE LATE AFTERNOON AND
EVENING ON THE PLAINS BETWEEN ABOUT BILLINGS AND MILES CITY AS THE
BOUNDARY LAYER MOISTENS ON THOSE SOUTHEAST WINDS. THAT SCENARIO IS
NOT OUT OF THE QUESTION SINCE THE AREA COULD BE ON THE EDGE OF THE
MID-LEVEL CAP...WITH 700-HPA TEMPERATURES ONLY AROUND 12 C. WE ARE
NOT SURE THAT THERE WILL ACTUALLY BE FORCING TO DEVELOP STORMS OUT
ON THE EDGE OF THE CAP THOUGH...WITH THE 12 UTC GFS KEEPING HEIGHT
FALLS OF ANY SIGNIFICANCE AT 500 HPA TO THE WEST OF BILLINGS. THAT
LINES UP WITH THE CALIBRATED THUNDERSTORM PROBABILITIES OFF OF THE
09 UTC SREF...WHICH ARE 40 PERCENT AT LIVINGSTON AND 10 PERCENT AT
MILES CITY ON MON. THUS...WE KEPT THE MON AFTERNOON PERIOD DRY FOR
SOUTHEASTERN MT...AND THEN ADVERTISED LOW POPS EVERYWHERE COME MON
EVENING. THERE WILL BE SOME SEVERE RISK IF STORMS FORM. NOTE IT IS
GOING TO BE DOWNRIGHT HOT ON MON TOO...WITH HIGHS AROUND 90 F OVER
MOST OF THE PLAINS AS WARM AIR ADVECTION REVS UP. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
12Z MEDIUM AND LONG RANGE MODELS REMAINED IN FAIR AGREEMENT WITH
THE UPPER TROUGH PROGGED TO MOVE INTO THE AREA ON TUESDAY. MODELS
STILL DEPICTING SOME MINOR DIFFERENCE BUT OVERALL ARE REMAINING
FAIRLY CONSISTENT.
LONG WAVE TROUGH MOVING OVER THE PACIFIC NORTHWEST STATES ON
TUESDAY WITH THE SYSTEM BECOMING NEGATIVELY TILTED. THIS WILL
ALLOW A RIDGE OF HIGH PRESSURE AND THERMAL RIDGE TO AMPLY OVER
THE FORECAST AREA. THIS WILL BRING A VERY WARM DAY TO THE THE
REGION WITH AFTERNOON READINGS IN THE LOW TO MID 90S. AS THE
UPPER TROUGH APPROACHES THE AREA TUESDAY...A STRONG LOW LEVEL JET
WILL DEVELOP AND ADVECT LOW LEVEL MOISTURE INTO THE AREA. MODELS
HAVE BEEN VERY CONSISTENT THE PAST SEVERAL DAYS IN BRINGING IN
VERY DRY AIR ALOFT FOR TUESDAY AND TUESDAY NIGHT. EVEN WITH VERY
DRY AIR ALOFT...SOME ENERGY WILL BE EJECTING OUT OF THE UPPER
TROUGH AND ACROSS OUR AREA. WILL CONTINUE CHANCE THUNDERSTORMS
FOR TUESDAY AND TUESDAY NIGHT EVEN THOUGH MODELS BRING IN DRY AIR
ALOFT. SHOULD CONTINUE TO SEE LOW LEVELS DESTABILIZE WITH HEATING
AND LIFT FROM UPPER ENERGY. UPPER TROUGH SHIFTING EASTWARD ON
WEDNESDAY WHICH WILL PUSH A STRONG COLD FRONT THROUGH THE AREA.
TIMING OF THE FRONT WITH THIS MODEL RUN WILL PUT IT OVER
SOUTHEAST MONTANA BY LATE AFTERNOON AND THIS AREA WILL HAVE THE
BETTER CHANCE OF POSSIBLE STRONG THUNDERSTORMS. UNSETTLED WEATHER
PATTERN TO CONTINUE THURSDAY THROUGH SATURDAY AS A BROAD CYCLONIC
FLOW WILL SET UP. THIS WILL BRING NEAR SEASON TEMPERATURES TO THE
AREA WITH LOWER HEIGHTS ACROSS THE REGION. RICHMOND
&&
.AVIATION...
A SURFACE COLD FRONT OVER WESTERN MONTANA WILL PUSH INTO THE KLVM
AREA LATE THIS AFTERNOON AND INTO SOUTHEAST MONTANA THIS EVENING.
SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT WITH A FEW
THUNDERSTORMS BECOMING SEVERE. THE MAIN THREAT FROM THESE STORMS
WILL BE STRONG WIND GUSTS IN EXCESS OF 55KTS AND 1 INCH HAIL. THE
STRONGER THUNDERSTORMS WILL CREATE AREAS OF MVFR/IFR CONDITIONS
DUE TO HEAVY RAIN LOWERING VISIBILITY AND CEILINGS. PRECIPITATION
WILL BRING WIDESPREAD MOUNTAIN OBSCURATION THIS EVENING.
CONDITIONS WILL IMPROVE BY LATE THIS EVENING WITH VFR CONDITIONS
PREVAILING OVER ALL FLIGHT TERMINALS. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 054/080 057/090 062/093 056/073 048/070 050/073 051/080
51/B 22/T 32/T 32/T 22/T 22/W 23/W
LVM 046/080 049/088 053/087 046/064 039/067 041/073 043/075
53/T 33/T 33/T 43/T 22/T 22/W 23/W
HDN 057/081 055/092 061/095 056/077 048/073 050/076 050/081
51/B 21/B 22/T 22/T 22/T 22/W 22/W
MLS 057/080 059/091 065/093 061/082 052/073 054/076 053/084
51/B 11/B 22/T 33/T 33/T 32/W 23/W
4BQ 058/079 056/090 063/091 059/082 051/072 052/076 051/083
51/B 11/B 22/T 23/T 33/T 32/W 22/W
BHK 057/077 057/086 060/087 057/080 051/071 053/075 050/081
51/B 11/B 22/T 34/T 43/T 42/W 22/W
SHR 050/081 054/087 060/091 055/074 046/068 047/072 048/078
51/B 21/B 21/B 22/T 22/T 22/W 23/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...SEVERE THUNDERSTORM WATCH 340 IN EFFECT UNTIL 9 PM MDT THIS
EVENING FOR ZONES 28>42-56>58-63>68.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
125 PM MDT SAT JUN 2 2012
.SHORT TERM...VALID FOR SUN AND MON...
THE POTENTIAL FOR SEVERE WIND OR HAIL THROUGH THIS EVENING REMAINS
THE FOCUS OF THE SHORT TERM. WE ALLOWED CONTINUITY TO RULE MUCH OF
THE SUN AND MON FORECAST...ESPECIALLY SINCE UNCERTAINTY GROWS WITH
REGARD TO STORM CHANCES ON MON.
FOR THE REST OF THIS AFTERNOON AND EVENING...SCATTERED STORMS WILL
AFFECT THE AREA...AND WE HAVE INCLUDED A SEVERE MENTION WITHIN THE
GRIDDED FORECAST EVERYWHERE GIVEN EFFECTIVE BULK SHEAR OF 30 TO 40
KT...MLCAPE OF 500 T0 1000 J/KG WITH STEEP 700-500 HPA LAPSE RATES
AROUND 8 DEG C/KM...AND INVERTED V-SOUNDING PROFILES. WIND WILL BE
THE MAIN THREAT...BUT MARGINALLY SEVERE HAIL IS POSSIBLE TOO. SOME
INITIAL CONVECTION IS MOVING THROUGH SOUTH CENTRAL MT AS OF 19 UTC
AND THAT ACTIVITY COULD STRENGTHEN...OR JUST BECOME MORE EFFECTIVE
AT PRODUCING STRONG WINDS...AS IT MOVES INTO THE DESTABILIZING AIR
MASS FROM SHERIDAN WY UP INTO SOUTHEASTERN MT. MEANWHILE...WE HAVE
HAD A SOLID AREA OF CLEARING BEHIND THE CLOUDS ASSOCIATED WITH THE
INITIAL CONVECTION...SO NEAR-TERM MODEL SOLUTIONS LOOK ON TRACK IN
SHOWING MLCAPE INCREASING QUICKLY THIS AFTERNOON. THE STORMS CLOSE
TO DILLON MT AT 19 UTC WILL BE TRACKING INTO THIS AIR MASS...AND A
SIMPLE EXTRAPOLATION TAKES THAT ACTIVITY INTO LIVINGSTON AROUND 21
UTC AND BILLINGS NEAR 23 UTC. THAT LINES UP WELL WITH COLD FRONTAL
TIMING SHOWN BY MOST MODELS...INCLUDING THE 18 UTC RAP AND 16 UTC
HRRR...WITH PASSAGE AT BILLINGS ADVERTISED AROUND 00 UTC. LOOK FOR
MOST OF THE ACTIVITY TO SETTLE DOWN BY ABOUT 03 UTC...WITH A QUIET
PERIOD FOR MOST OF THE AREA OVERNIGHT.
SUN...A SURFACE HIGH PRESSURE RIDGE WILL SLIDE FROM EASTERN MT AND
INTO THE WESTERN DAKOTAS BENEATH A NEBULOUS WEST-SOUTHWEST 500-HPA
FLOW. LOW-LEVEL EASTERLY FLOW AND 500 J/KG OF MLCAPE COULD SUPPORT
SOME AFTERNOON AND EVENING STORMS IN AND NEAR THE HIGH TERRAIN. WE
CHOSE TO KEEP EVEN LOW CHANCES OF CONVECTION OUT OF BILLINGS UNTIL
AFTER 00 UTC THOUGH BECAUSE FORECAST SOUNDINGS SHOW MINIMAL MLCAPE
AND MODEST CAPPING OVER THAT AREA DURING THE DAY. WE ARE SHOWING A
SLIGHT CHANCE OF STORMS OVER THE PLAINS OF SOUTH CENTRAL MT ON SUN
NIGHT...BUT ONLY A WEAK LOW-LEVEL JET IS SHOWN BY THE LAST SEVERAL
MODEL SIMULATIONS. THUS...THE CONVECTION MAY END UP BEING REMNANTS
OF THE STUFF THAT COMES OFF THE HIGH TERRAIN...RATHER THAN ANY NEW
DEVELOPMENT. THAT MAY RESULT IN MINIMAL COVERAGE AFTER 06 UTC.
MON...LOW-LEVEL SOUTHEAST FLOW IS EXPECTED TO INCREASE AS PRESSURE
FALLS COMMENCE OVER THE REGION. THE 12 UTC NAM /AND MOST PAST RUNS
OF THAT MODEL/ SIMULATES DEEP CONVECTION IN THE LATE AFTERNOON AND
EVENING ON THE PLAINS BETWEEN ABOUT BILLINGS AND MILES CITY AS THE
BOUNDARY LAYER MOISTENS ON THOSE SOUTHEAST WINDS. THAT SCENARIO IS
NOT OUT OF THE QUESTION SINCE THE AREA COULD BE ON THE EDGE OF THE
MID-LEVEL CAP...WITH 700-HPA TEMPERATURES ONLY AROUND 12 C. WE ARE
NOT SURE THAT THERE WILL ACTUALLY BE FORCING TO DEVELOP STORMS OUT
ON THE EDGE OF THE CAP THOUGH...WITH THE 12 UTC GFS KEEPING HEIGHT
FALLS OF ANY SIGNIFICANCE AT 500 HPA TO THE WEST OF BILLINGS. THAT
LINES UP WITH THE CALIBRATED THUNDERSTORM PROBABILITIES OFF OF THE
09 UTC SREF...WHICH ARE 40 PERCENT AT LIVINGSTON AND 10 PERCENT AT
MILES CITY ON MON. THUS...WE KEPT THE MON AFTERNOON PERIOD DRY FOR
SOUTHEASTERN MT...AND THEN ADVERTISED LOW POPS EVERYWHERE COME MON
EVENING. THERE WILL BE SOME SEVERE RISK IF STORMS FORM. NOTE IT IS
GOING TO BE DOWNRIGHT HOT ON MON TOO...WITH HIGHS AROUND 90 F OVER
MOST OF THE PLAINS AS WARM AIR ADVECTION REVS UP. SCHULTZ
.LONG TERM...VALID FOR TUE...WED...THU...FRI...SAT...
12Z MEDIUM AND LONG RANGE MODELS REMAINED IN FAIR AGREEMENT WITH
THE UPPER TROUGH PROGGED TO MOVE INTO THE AREA ON TUESDAY. MODELS
STILL DEPICTING SOME MINOR DIFFERENCE BUT OVERALL ARE REMAINING
FAIRLY CONSISTENT.
LONG WAVE TROUGH MOVING OVER THE PACIFIC NORTHWEST STATES ON
TUESDAY WITH THE SYSTEM BECOMING NEGATIVELY TILTED. THIS WILL
ALLOW A RIDGE OF HIGH PRESSURE AND THERMAL RIDGE TO AMPLY OVER
THE FORECAST AREA. THIS WILL BRING A VERY WARM DAY TO THE THE
REGION WITH AFTERNOON READINGS IN THE LOW TO MID 90S. AS THE
UPPER TROUGH APPROACHES THE AREA TUESDAY...A STRONG LOW LEVEL JET
WILL DEVELOP AND ADVECT LOW LEVEL MOISTURE INTO THE AREA. MODELS
HAVE BEEN VERY CONSISTENT THE PAST SEVERAL DAYS IN BRINGING IN
VERY DRY AIR ALOFT FOR TUESDAY AND TUESDAY NIGHT. EVEN WITH VERY
DRY AIR ALOFT...SOME ENERGY WILL BE EJECTING OUT OF THE UPPER
TROUGH AND ACROSS OUR AREA. WILL CONTINUE CHANCE THUNDERSTORMS
FOR TUESDAY AND TUESDAY NIGHT EVEN THOUGH MODELS BRING IN DRY AIR
ALOFT. SHOULD CONTINUE TO SEE LOW LEVELS DESTABILIZE WITH HEATING
AND LIFT FROM UPPER ENERGY. UPPER TROUGH SHIFTING EASTWARD ON
WEDNESDAY WHICH WILL PUSH A STRONG COLD FRONT THROUGH THE AREA.
TIMING OF THE FRONT WITH THIS MODEL RUN WILL PUT IT OVER
SOUTHEAST MONTANA BY LATE AFTERNOON AND THIS AREA WILL HAVE THE
BETTER CHANCE OF POSSIBLE STRONG THUNDERSTORMS. UNSETTLED WEATHER
PATTERN TO CONTINUE THURSDAY THROUGH SATURDAY AS A BROAD CYCLONIC
FLOW WILL SET UP. THIS WILL BRING NEAR SEASON TEMPERATURES TO THE
AREA WITH LOWER HEIGHTS ACROSS THE REGION. RICHMOND
&&
.AVIATION...
A SURFACE COLD FRONT OVER WESTERN MONTANA WILL PUSH INTO THE KLVM
AREA LATE THIS AFTERNOON AND INTO SOUTHEAST MONTANA THIS EVENING.
SHOWERS AND THUNDERSTORMS WILL DEVELOP ALONG THE FRONT WITH A FEW
THUNDERSTORMS BECOMING SEVERE. THE MAIN THREAT FROM THESE STORMS
WILL BE STRONG WIND GUSTS IN EXCESS OF 55KTS AND 1 INCH HAIL. THE
STRONGER THUNDERSTORMS WILL CREATE AREAS OF MVFR/IFR CONDITIONS
DUE TO HEAVY RAIN LOWERING VISIBILITY AND CEILINGS. PRECIPITATION
WILL BRING WIDESPREAD MOUNTAIN OBSCURATION THIS EVENING.
CONDITIONS WILL IMPROVE BY LATE THIS EVENING WITH VFR CONDITIONS
PREVAILING OVER ALL FLIGHT TERMINALS. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
SUN MON TUE WED THU FRI SAT
-----------------------------------------------------------
BIL 054/080 057/090 062/093 056/073 048/070 050/073 051/080
51/B 22/T 32/T 32/T 22/T 22/W 23/W
LVM 046/080 049/088 053/087 046/064 039/067 041/073 043/075
53/T 33/T 33/T 43/T 22/T 22/W 23/W
HDN 057/081 055/092 061/095 056/077 048/073 050/076 050/081
51/B 21/B 22/T 22/T 22/T 22/W 22/W
MLS 057/080 059/091 065/093 061/082 052/073 054/076 053/084
51/B 11/B 22/T 33/T 33/T 32/W 23/W
4BQ 058/079 056/090 063/091 059/082 051/072 052/076 051/083
51/B 11/B 22/T 23/T 33/T 32/W 22/W
BHK 057/077 057/086 060/087 057/080 051/071 053/075 050/081
51/B 11/B 22/T 34/T 43/T 42/W 22/W
SHR 050/081 054/087 060/091 055/074 046/068 047/072 048/078
51/B 21/B 21/B 22/T 22/T 22/W 23/W
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
312 PM CDT SAT JUN 2 2012
.SHORT TERM...
FOCUS CONTINUES ON STORM CHANCES THROUGH TONIGHT AND AGAIN ON SUNDAY
AFTERNOON. MID-LEVEL FLOW WAS BACKING AND WEAKENING A BIT /AS SEEN
IN THE TUCUMCARI PROFILER DATA/ AS THE UPPER RIDGE AXIS WAS SHIFTING
FROM THE EASTERN ROCKIES ACROSS THE HIGH PLAINS. AN EJECTING
EMBEDDED DISTURBANCE AND PLENTY OF MID-LEVEL MOISTURE WAS ALREADY
RESULTING IN WIDESPREAD CONVECTION ACROSS THE HIGHER TERRAIN OF
CENTRAL CO INTO NORTHEAST NM. THIS ACTIVITY WILL LIKELY CONGEAL INTO
ONE OR MORE MESOSCALE CONVECTIVE SYSTEMS AS IT TRANSLATES
EAST-SOUTHEASTWARD ACROSS THE PANHANDLES AND PERHAPS OVER OUR
NORTHERN ZONES THIS EVENING. LIFT WITH THE APPROACHING WAVE WAS ALSO
ENHANCING THE MID-LEVEL CLOUD FIELD ACROSS EAST-CENTRAL NM...AND
HIGH-BASED CONVECTION COULD MATERIALIZE WITHIN THE SFC TROUGH HERE
TOO LATE THIS AFTERNOON. LAST PLACE OF CONCERN FOR POSSIBLE
CONVECTIVE INITIATION WILL BE ALONG A RETREATING BOUNDARY NOTED ON
RADAR LIFTING NORTHWARD THROUGH THE SOUTHERN TEXAS PANHANDLE. UP TO
THIS POINT CU DEVELOPMENT ALONG THE BOUNDARY HAS BEEN FAIRLY TAME.
HOWEVER...BOTH THE 18Z RAP AND 16Z HRRR DO INDICATE ISOLATED TO
WIDELY SCATTERED CONVECTION DEVELOPING OVER THE NEXT 1-3 HR IN CLOSE
PROXIMITY TO OUR NORTHWEST ZONES. 19Z LAPS ANALYSIS SHOWS SFC BASED
CAPES OF 800-2400 J/KG WITH DIMINISHING CIN. GIVEN T/TD SPREADS
AROUND 50 DEGREES ACROSS THE WESTERN ZONES...STRONG DOWNBURST WINDS
WILL BE A CONCERN WITH ANY STRONGER CORES ALOFT AND THE INSTABILITY
COULD ALSO SUPPORT THE OCCURRENCE OF LARGE HAIL. ALL SAID...HAVE
DRAWN CHANCE POPS ACROSS THE N/NW/W ZONES...TAPERING TO SLIGHT
CHANCE ACROSS THE SOUTHERN ROLLING PLAINS TONIGHT. ACTIVITY SHOULD
WANE LATE TONIGHT...THOUGH STRENGTHENING SOUTHERLY LLJ COULD KEEP
SOME ACTIVITY GOING THROUGH EARLY SUNDAY MORNING...FAVORING THE
NORTHEAST ZONES. SOUTHERLY BREEZES...DECENT MOISTURE LEVELS AND SOME
CLOUD COVER WILL KEEP TEMPERATURES MILD...WITH LOWS ONLY IN THE 60S
TO LOWER 70S.
HEIGHTS WILL BE EVEN HIGHER ON SUNDAY WITH QUASI-ZONAL FLOW ALOFT.
THIS FLOW REGIME WILL CAUSE THE SFC TROUGH/DRYLINE TO ADVANCE
EASTWARD INTO THE SOUTH PLAINS BY AFTERNOON. ALTHOUGH LARGE SCALE
SUPPORT WILL BE MINIMAL AT BEST...STRONG HEATING/MIXING COUPLED WITH
THE DRYLINE MAY BE ENOUGH TO GENERATE ISOLATED TO WIDELY SCATTERED
LATE AFTERNOON HIGH-BASED STORMS. DEEP LAYER SHEAR WILL BE RATHER
WEAK /AOB 20 KTS/...SO STORM ORGANIZATION WILL BE TOUGH TO COME
BY...BUT MODERATE INSTABILITY AND A DEEPLY MIXED BL COULD SUPPORT AN
ISOLATED STRONG/SEVERE STORM. TEMPERATURES WILL SOAR WITH HIGHS NEAR
THE CENTURY MARK EXPECTED.
&&
.LONG TERM...
MODELS CONTINUE TO TREND TO POTENTIALLY WET WEATHER INTO THE
MIDDLE OF THE WEEK BUILDING ON YESTERDAYS TURNABOUT WITH RESPECT
TO LOW LEVEL FLOW AND STRENGTH OF UPPER LEVEL RIDGING. 12Z RUNS
CONTINUE TO SHOW AN AMPLIFIED FLOW ACROSS THE CONUS EARLY IN THE
WEEK WITH A NARROW BUT FAIRLY WEAK UPPER LEVEL RIDGE OVER THE
PLAINS STATES WHILE AT THE SFC A COLD FRONT IS PROGGED TO BACK
INTO THE NRN ZONES MONDAY THEN SLIP FURTHER SOUTH TUESDAY. BACKING
FLOW TO SE THEN EVENTUALLY EAST SHOULD HELP KEEP LOW LEVEL
MOISTURE IN PLACE ACROSS THE AREA AND THE DRYLINE FROM MIXING TOO
FAR TO THE EAST. INCREASING MID LEVEL MOISTURE TRAPPED IN THE
RIDGE LEADING TO PROGGED PWAT BETWEEN 1 AND 1.5 INCHES MONDAY WITH
EASTERN AREAS INCREASING TO AROUND 1.75 INCHES TUESDAY AND
WEDNESDAY. WHEN CONSIDERING RELATIVELY WEAK FLOW ALOFT UNDER THE
RIDGE STORM ORGANIZATION NOT TOO LIKELY THUS PRECIP COULD END UP
BEING SCATTERED...BUT HIGHER PWATS SUGGEST SOME LOCALLY HEAVIER
RAINFALL NOT OUT OF THE QUESTION. WILL CONTINUE WITH PRECIP
MENTION FOR MONDAY FAVORING NRN ZONES CLOSEST TO EXPECTED BOUNDARY
POSITION AND INSERT PRECIP MENTION INTO TUESDAY AND WEDNESDAY.
CURRENT INDICATIONS ARE THAT THE RIDGE WILL STRENGTHEN ENOUGH
TOWARD THE END OF THE WEEK TO POTENTIALLY END PRECIP CHANCES. WITH
UPSLOPE FLOW AND POTENTIALLY AN INCREASE IN CLOUD COVER COOLER
TEMPS SHOULD BE IN THE OFFING FOR THE FIRST HALF OF THE WEEK...
ALTHOUGH GIVEN PROGGED THICKNESSES IT APPEARS MOS GUIDANCE MAY BE
A TOUCH COOL AND WILL GENERALLY TREND TOWARD WARMER END OF
ENSEMBLE NUMBERS FOR DAYTIME HIGHS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 98 62 93 62 / 40 10 10 20 30
TULIA 66 98 65 92 65 / 40 20 20 20 30
PLAINVIEW 68 97 66 93 65 / 30 20 20 20 20
LEVELLAND 66 99 67 96 65 / 20 20 20 20 20
LUBBOCK 69 100 69 96 67 / 20 20 20 20 20
DENVER CITY 67 99 67 96 63 / 20 20 10 20 20
BROWNFIELD 67 100 67 96 65 / 20 20 20 20 20
CHILDRESS 69 101 70 96 68 / 30 20 20 10 30
SPUR 69 101 69 97 68 / 20 20 20 10 20
ASPERMONT 70 100 71 98 70 / 20 10 20 20 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23/07
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1249 PM CDT SAT JUN 2 2012
.AVIATION...
AN OUTFLOW BOUNDARY WAS LOCATED BETWEEN LBB AND CDS AS OF
17Z...WITH LIGHT AND VARIABLE WINDS TO ITS NORTHEAST. THIS
BOUNDARY WILL GRADUALLY LIFT NORTHWARD THIS AFTERNOON...WITH
BREEZY SOUTHERLY WINDS ENSUING AT LBB...THOUGH WINDS WILL LIKELY
STAY ON THE LIGHT SIDE AT CDS THROUGH MUCH OF THE AFTERNOON. THIS
BOUNDARY...ALONG WITH A SFC TROUGH NEAR THE TX/NM STATE
LINE...COULD PROVIDE A FOCUS FOR LATE AFTERNOON CONVECTION.
STILL...CONFIDENCE THAT A STORM WILL DIRECTLY AFFECT EITHER TERMINAL
THROUGH THE EARLY EVENING HOURS IS LOW AND HAVE LEFT OUT OF THE
TAFS FOR NOW AND WILL AMEND IF NEEDED. GREATER CONFIDENCE THAT A
SMALL COMPLEX OF STORMS MAY MOVE ACROSS THE PANHANDLES TONIGHT AND
COULD POTENTIAL AFFECT CDS LATER TONIGHT...AND HAVE INCLUDED A
PROB30 GROUP VALID FROM 3-9Z TONIGHT WITH THIS IN MIND. ASIDE FROM
A DIRECT IMPACT BY A STORM...EXPECT VFR CONDITIONS TO PREVAIL AT
THE TERMINALS THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 1207 PM CDT SAT JUN 2 2012/
UPDATE...
EARLY MORNING SHOWERS AND EMBEDDED ISOLATED STORMS HAVE DIMINISHED
AND SHIFTED TO THE SOUTHEAST...WITH A MCV NOTED VIA RADAR DATA
SPINNING NEAR BENJAMIN. THIS ACTIVITY SHOULD HAVE LITTLE IMPACT ON
THE FUTURE FORECAST...THOUGH THERE IS A WEAK SFC BOUNDARY THAT
HAS FILTERED IN FROM THE NORTHEAST IN ITS WAKE...WITH WEAK AND
VARIABLE SFC WINDS NOTED ACROSS ROUGHLY THE NE HALF OF THE FA AS
OF 1630Z. THIS BOUNDARY IS FORECAST TO GRADUAL WASH OUT THROUGH
THE AFTERNOON AND LIFT NORTHWARD...THOUGH THERE IS A SLIM CHANCE
IT COULD PROVIDE ENOUGH OF A FOCUS FOR LATE AFTERNOON CI ACROSS
THE NE ZONES. HOWEVER...RECENT HIGH-RES NWP HAS BACKED OFF ON QPF
GENERATION WITH THIS FEATURE AND HAVE TRENDED POPS DOWN THERE
/MAINTAINING A MINIMAL SLIGHT CHANCE/. ELSEWHERE...A SFC TROUGH
PRESENT NEAR THE TX/NM LINE COULD PROVIDE ENOUGH CONVERGENCE TO
POP ISOLATED LATE AFTERNOON STORMS...AND THE RECENT RAP RUNS HAVE
STARTED TO LEND SUPPORT TO THIS. IF STORMS DEVELOP
LOCALLY...MODERATE INSTABILITY WILL BE PRESENT...WITH DEEP LAYER
SHEAR RANGING FROM AROUND 20 KTS SOUTH TO 30 TO 35 KTS
NORTH...SO A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE.
GREATER DEVELOPMENT/COVERAGE OF CONVECTION IS PROJECTED TO TAKE
SHAPE ACROSS NE NM AND EASTERN CO AS A SHORTWAVE TROUGH EMERGES
ACROSS THE CENTRAL HIGH PLAINS THIS AFTERNOON. MODEST UPPER LEVEL
FLOW WILL BACK TO NEAR ZONAL...BUT A SMALL MCS OR TWO MAY ORGANIZE
FROM THE HIGHER TERRAIN CONVECTION WELL TO THE NW AND PROPAGATE
EAST-SOUTHEASTWARD. THIS ACTIVITY COULD CLIP THE N/NE ZONES THIS
EVENING AND BRING THE RISK OF LARGE HAIL AND DAMAGING WINDS. HAVE
TRIMMED POPS A BIT ACROSS THE CENTRAL AND SOUTHEAST ZONES
TONIGHT...WHILE MAINTAINING 40 POPS ACROSS THE NORTHERN ZONES.
OTHERWISE...HAVE ADJUSTED THE SHORT TERM WIND AND DEWPOINT GRIDS
TO BETTER REFLECT RECENT OBSERVATIONS AND TRENDS.
PREV DISCUSSION... /ISSUED 453 AM CDT SAT JUN 2 2012/
SHORT TERM...
UPPER RIDGE PASSING OVERHEAD LATER TODAY WILL BE FLATTENING AS THE
NEXT CONVECTIVE-ENHANCED DISTURBANCE EDGES THROUGH THE SOUTHERN
ROCKIES. CONVERGENCE WILL CONTINUE INTO A SURFACE LOW PRESSURE
TROUGH LYING NEAR THE WESTERN SOUTH PLAINS AND THE NEW MEXICO
LINE...WHILE TONIGHTS DYING ACTIVITY LIKELY TO ALSO LAY A BOUNDARY
DOWN NORTHWEST TO SOUTHEAST THAT SHOULD TEND TO LIFT BACK NORTHWARD
BY AFTERNOON AND HELP CATALYZE THUNDER ACTIVITY AGAIN OVER THE
PANHANDLE. BEST SHEAR VALUES EXPECTED TO BE ACROSS THE PANHANDLE AS
WELL...WHILE STRONGER SURFACE HEATING SHOULD LEAD TO MODEST
INSTABILITY MANY AREAS AS WELL. ANYWAY...BULK OF CLUES TONIGHT POINT
TOWARDS PANHANDLE AS HAVING BEST CAPABILITY FOR ORGANIZED SEVERE
THUNDERSTORMS LATER TODAY...THOUGH TENDENCY FOR OUTFLOWS WILL
EXTEND CHANCES FURTHER SOUTH AND EAST LATER IN THE EVENT. ALSO...WE
CANNOT RULE OUT INITIATION OVER AT LEAST OUR WESTERN ZONES SHOULD
SURFACE CONVERGENCE MATERIALIZE PER WRF/NAM. ALL-IN-ALL...THIS LEADS
TO A CHANCE OF THUNDER MAINLY NORTH AND WESTERN ZONES EDGING SOUTH
AND EAST DURING THE EVENING. ALSO CANNOT RULE OUT ISOLATED SEVERE
RISK THOUGH PANHANDLE AGAIN SHOULD SEE PRIMARY RISK AREA. OTHER
FORECAST FIELDS LARGELY RETAINED. RMCQUEEN
LONG TERM...
OVERVIEW...
ALTHOUGH MODELS REMAIN LARGELY SIMILAR IN AMPLIFYING AN UPPER
RIDGE OVER THE MIDDLE CONUS EARLY NEXT WEEK...THERE HAS BEEN A
SHIFT IN MODEL OUTPUT OVER THE LAST 24 HOURS REGARDING THE LOWER
TROPOSPHERIC PATTERN DURING THIS TIME. ESSENTIALLY THIS CHANGE
INVOLVES A MORE STOUT AND MERIDIONAL SURFACE RIDGE POISED TO
RESIDE FROM THE GREAT LAKES SOUTH TO THE MID-MISSISSIPPI VALLEY
WHICH WILL TEND TO INFLUENCE OUR MEAN SURFACE FLOW WITH MORE OF AN
EASTERLY COMPONENT BEGINNING MONDAY AND PERHAPS LASTING THROUGH
THE BETTER PORTION OF THE WEEK AHEAD.
SUNDAY AND MONDAY...
AS HEIGHT RISES TAKE GRASP SUNDAY ACCOMPANIED BY RISING
THICKNESSES...A DRYLINE IS FORECAST TO BISECT THE CWA SUNDAY AFTN
AHEAD OF A DEEPLY MIXED BOUNDARY LAYER. HI TEMPS FOR THIS ENTIRE
FORECAST WINDOW SHOULD PROVE THEIR HOTTEST SUN AS THIS PROCESS
OCCURS...ALTHOUGH SOME RELIEF IN THE FORM OF VERY ISO TSRA NEAR
THE DRYLINE STILL APPEARS PLAUSIBLE BY LATE AFTN DESPITE MINIMAL
BACKGROUND FORCING. MEANWHILE FARTHER NORTH...A MINOR TROUGH WILL
BE FOUND MOTORING EAST ACROSS KANSAS. THIS IS IMPORTANT IN THAT A
WEAK COLD FRONT WILL BE CARRIED SOUTH IN ITS WAKE SUN NIGHT JUST
DOWNSTREAM OF A BURGEONING UPPER RIDGE AXIS IN THE LEE OF THE
ROCKIES. ALL MODELS SHOW THIS BOUNDARY STALLING OVER THE SOUTH
PLAINS MONDAY AFTN AND FOR THIS REASON WE HAVE INTRODUCED PRECIP
MENTION OVER THE NORTHERN HALF OF THE CWA WHERE POST-FRONTAL
MOISTURE APPEARS MOST FAVORABLE FOR CONVECTION.
TUESDAY THROUGH SATURDAY...
DAILY PRECIP CHANCES MAY INDEED BE IN THE OFFING AS MOISTURE
REMAINS TRAPPED UNDERNEATH THE RIDGE...HOWEVER AM CONCERNED THAT
THE GLOBAL AND REGIONAL MODELS ARE BEING PLAGUED WITH CONVECTIVE
FEEDBACK IN THIS ANEMIC UPPER FLOW REGIME. THE FRONTAL BOUNDARY
INHERITED FROM MONDAY COULD CERTAINLY REMAIN IN THE CWA TO SOME
DEGREE COME TUESDAY...BUT THIS SHOULD BE WASHING OUT WITH TIME AND
PROVE LESS OF A FACTOR FOR CONVECTIVE INITIATION. THE DRYLINE MAY
ALSO BE A NO SHOW SHOULD DEEP SELY FLOW DEVELOP PER THE GFS AND TO
A LESSER EXTENT THE ECMWF. THIS WOULD BACK MOISTURE WELL INTO THE
PLAINS OF NEW MEXICO LEAVING OUR PRECIP CHANCES TIED MOSTLY TO
DIABATIC HEATING AND/OR UPSLOPE MECHANISMS. SINCE THIS CHANGE TO
A MORE MOIST LL FLOW IS STILL RELATIVELY RECENT...WE WILL PREFER
TO AWAIT LATER MODEL RUNS BEFORE BLANKETING POPS ANY OR ALL DAYS.
CONFIDENCE IS HIGHER THAT IN MAX TEMPS BEING COOLER THAN WE
PREVIOUSLY THOUGHT...SO VALUES AREA WIDE WERE KNOCKED BACK ABOUT
3-6 DEG EACH DAY. IT IS INTERESTING TO NOTE THAT MODEL SOUNDINGS
FOR MUCH OF NEXT WEEK ARE REMINISCENT OF A MID-SUMMER PATTERN
WITH PRACTICALLY NIL STEERING FLOW AND PWATS OVER 1 INCH DURING
BOTH DAY AND NIGHT. WHERE THIS DIFFERS HOWEVER IS WITH LAPSE RATES
WHICH APPEAR RATHER STEEP AT TIMES LENDING TO AMPLE CAPE AND
SUBSEQUENT CONVECTIVE FEEDBACK CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 61 99 61 94 62 / 40 10 10 20 20
TULIA 65 100 65 92 66 / 40 20 10 20 20
PLAINVIEW 67 98 66 93 66 / 30 20 10 20 20
LEVELLAND 65 100 66 96 66 / 20 20 10 10 10
LUBBOCK 69 101 68 96 68 / 20 20 10 10 10
DENVER CITY 65 100 66 97 64 / 20 10 10 10 10
BROWNFIELD 66 101 66 97 66 / 20 20 10 10 10
CHILDRESS 69 102 70 96 70 / 30 20 20 20 20
SPUR 68 102 68 96 69 / 20 20 20 10 10
ASPERMONT 70 101 71 98 72 / 20 10 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1207 PM CDT SAT JUN 2 2012
.UPDATE...
EARLY MORNING SHOWERS AND EMBEDDED ISOLATED STORMS HAVE DIMINISHED
AND SHIFTED TO THE SOUTHEAST...WITH A MCV NOTED VIA RADAR DATA
SPINNING NEAR BENJAMIN. THIS ACTIVITY SHOULD HAVE LITTLE IMPACT ON
THE FURTURE FORECAST...THOUGH THERE IS A WEAK SFC BOUNDARY THAT
HAS FILTERED IN FROM THE NORTHEAST IN ITS WAKE...WITH WEAK AND
VARIABLE SFC WINDS NOTED ACROSS ROUGHLY THE NE HALF OF THE FA AS
OF 1630Z. THIS BOUNDARY IS FORECAST TO GRADUAL WASH OUT THROUGH
THE AFTERNOON AND LIFT NORTHWARD...THOUGH THERE IS A SLIM CHANCE
IT COULD PROVIDE ENOUGH OF A FOCUS FOR LATE AFTERNOON CI ACROSS
THE NE ZONES. HOWEVER...RECENT HIGH-RES NWP HAS BACKED OFF ON QPF
GENERATION WITH THIS FEATURE AND HAVE TRENDED POPS DOWN THERE
/MAINTAINING A MINIMAL SLIGHT CHANCE/. ELSEWHERE...A SFC TROUGH
PRESENT NEAR THE TX/NM LINE COULD PROVIDE ENOUGH CONVERGENCE TO
POP ISOLATED LATE AFTERNOON STORMS...AND THE RECENT RAP RUNS HAVE
STARTED TO LEND SUPPORT TO THIS. IF STORMS DEVELOP
LOCALLY...MODERATE INSTABILITY WILL BE PRESENT...WITH DEEP LAYER
SHEAR RANGING FROM AROUND 20 KTS SOUTH TO 30 TO 35 KTS
NORTH...SO A FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE.
GREATER DEVELOPMENT/COVERAGE OF CONVECTION IS PROJECTED TO TAKE
SHAPE ACROSS NE NM AND EASTERN CO AS A SHORTWAVE TROUGH EMERGES
ACROSS THE CENTRAL HIGH PLAINS THIS AFTERNOON. MODEST UPPER LEVEL
FLOW WILL BACK TO NEAR ZONAL...BUT A SMALL MCS OR TWO MAY ORGANIZE
FROM THE HIGHER TERRAIN CONVECTION WELL TO THE NW AND PROPAGATE
EAST-SOUTHEASTWARD. THIS ACTIVITY COULD CLIP THE N/NE ZONES THIS
EVENING AND BRING THE RISK OF LARGE HAIL AND DAMAGING WINDS. HAVE
TRIMMED POPS A BIT ACROSS THE CENTRAL AND SOUTHEAST ZONES
TONIGHT...WHILE MAINTAINING 40 POPS ACROSS THE NORTHERN ZONES.
OTHERWISE...HAVE ADJUSTED THE SHORT TERM WIND AND DEWPOINT GRIDS
TO BETTER REFLECT RECENT OBSERVATIONS AND TRENDS.
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT SAT JUN 2 2012/
AVIATION...
CONTINUED VFR. SMALL LINE OF -TSRA AFFECTING LBB WILL CLEAR THE
TERMINAL SHORTLY WITHOUT DISRUPTING VFR LEVELS. OTHERWISE EXPECT
EXTENSIVE MID LAYER CLOUDS TO SLOWLY ERODE BY MIDDAY BEFORE A
MORE ORGANIZED ROUND OF TSRA DEVELOPS NORTH OF LBB AND STANDS TO
THREATEN CDS BY EARLY EVENING. WILL KEEP PROB30 MENTION FOR NOW AT
CDS...THOUGH SOME POTENTIAL REMAINS FOR STORMS TO REMAIN NORTH OF
CDS CLOSE TO A RETREATING FRONTAL BOUNDARY.
PREV DISCUSSION... /ISSUED 453 AM CDT SAT JUN 2 2012/
SHORT TERM...
UPPER RIDGE PASSING OVERHEAD LATER TODAY WILL BE FLATTENING AS THE
NEXT CONVECTIVE-ENHANCED DISTURBANCE EDGES THROUGH THE SOUTHERN
ROCKIES. CONVERGENCE WILL CONTINUE INTO A SURFACE LOW PRESSURE
TROUGH LYING NEAR THE WESTERN SOUTH PLAINS AND THE NEW MEXICO
LINE...WHILE TONIGHTS DYING ACTIVITY LIKELY TO ALSO LAY A BOUNDARY
DOWN NORTHWEST TO SOUTHEAST THAT SHOULD TEND TO LIFT BACK NORTHWARD
BY AFTERNOON AND HELP CATALYZE THUNDER ACTIVITY AGAIN OVER THE
PANHANDLE. BEST SHEAR VALUES EXPECTED TO BE ACROSS THE PANHANDLE AS
WELL...WHILE STRONGER SURFACE HEATING SHOULD LEAD TO MODEST
INSTABILITY MANY AREAS AS WELL. ANYWAY...BULK OF CLUES TONIGHT POINT
TOWARDS PANHANDLE AS HAVING BEST CAPABILITY FOR ORGANIZED SEVERE
THUNDERSTORMS LATER TODAY...THOUGH TENDENCY FOR OUTFLOWS WILL
EXTEND CHANCES FURTHER SOUTH AND EAST LATER IN THE EVENT. ALSO...WE
CANNOT RULE OUT INITIATION OVER AT LEAST OUR WESTERN ZONES SHOULD
SURFACE CONVERGENCE MATERIALIZE PER WRF/NAM. ALL-IN-ALL...THIS LEADS
TO A CHANCE OF THUNDER MAINLY NORTH AND WESTERN ZONES EDGING SOUTH
AND EAST DURING THE EVENING. ALSO CANNOT RULE OUT ISOLATED SEVERE
RISK THOUGH PANHANDLE AGAIN SHOULD SEE PRIMARY RISK AREA. OTHER
FORECAST FIELDS LARGELY RETAINED. RMCQUEEN
LONG TERM...
OVERVIEW...
ALTHOUGH MODELS REMAIN LARGELY SIMILAR IN AMPLIFYING AN UPPER
RIDGE OVER THE MIDDLE CONUS EARLY NEXT WEEK...THERE HAS BEEN A
SHIFT IN MODEL OUTPUT OVER THE LAST 24 HOURS REGARDING THE LOWER
TROPOSPHERIC PATTERN DURING THIS TIME. ESSENTIALLY THIS CHANGE
INVOLVES A MORE STOUT AND MERIDIONAL SURFACE RIDGE POISED TO
RESIDE FROM THE GREAT LAKES SOUTH TO THE MID-MISSISSIPPI VALLEY
WHICH WILL TEND TO INFLUENCE OUR MEAN SURFACE FLOW WITH MORE OF AN
EASTERLY COMPONENT BEGINNING MONDAY AND PERHAPS LASTING THROUGH
THE BETTER PORTION OF THE WEEK AHEAD.
SUNDAY AND MONDAY...
AS HEIGHT RISES TAKE GRASP SUNDAY ACCOMPANIED BY RISING
THICKNESSES...A DRYLINE IS FORECAST TO BISECT THE CWA SUNDAY AFTN
AHEAD OF A DEEPLY MIXED BOUNDARY LAYER. HI TEMPS FOR THIS ENTIRE
FORECAST WINDOW SHOULD PROVE THEIR HOTTEST SUN AS THIS PROCESS
OCCURS...ALTHOUGH SOME RELIEF IN THE FORM OF VERY ISO TSRA NEAR
THE DRYLINE STILL APPEARS PLAUSIBLE BY LATE AFTN DESPITE MINIMAL
BACKGROUND FORCING. MEANWHILE FARTHER NORTH...A MINOR TROUGH WILL
BE FOUND MOTORING EAST ACROSS KANSAS. THIS IS IMPORTANT IN THAT A
WEAK COLD FRONT WILL BE CARRIED SOUTH IN ITS WAKE SUN NIGHT JUST
DOWNSTREAM OF A BURGEONING UPPER RIDGE AXIS IN THE LEE OF THE
ROCKIES. ALL MODELS SHOW THIS BOUNDARY STALLING OVER THE SOUTH
PLAINS MONDAY AFTN AND FOR THIS REASON WE HAVE INTRODUCED PRECIP
MENTION OVER THE NORTHERN HALF OF THE CWA WHERE POST-FRONTAL
MOISTURE APPEARS MOST FAVORABLE FOR CONVECTION.
TUESDAY THROUGH SATURDAY...
DAILY PRECIP CHANCES MAY INDEED BE IN THE OFFING AS MOISTURE
REMAINS TRAPPED UNDERNEATH THE RIDGE...HOWEVER AM CONCERNED THAT
THE GLOBAL AND REGIONAL MODELS ARE BEING PLAGUED WITH CONVECTIVE
FEEDBACK IN THIS ANEMIC UPPER FLOW REGIME. THE FRONTAL BOUNDARY
INHERITED FROM MONDAY COULD CERTAINLY REMAIN IN THE CWA TO SOME
DEGREE COME TUESDAY...BUT THIS SHOULD BE WASHING OUT WITH TIME AND
PROVE LESS OF A FACTOR FOR CONVECTIVE INITIATION. THE DRYLINE MAY
ALSO BE A NO SHOW SHOULD DEEP SELY FLOW DEVELOP PER THE GFS AND TO
A LESSER EXTENT THE ECMWF. THIS WOULD BACK MOISTURE WELL INTO THE
PLAINS OF NEW MEXICO LEAVING OUR PRECIP CHANCES TIED MOSTLY TO
DIABATIC HEATING AND/OR UPSLOPE MECHANISMS. SINCE THIS CHANGE TO
A MORE MOIST LL FLOW IS STILL RELATIVELY RECENT...WE WILL PREFER
TO AWAIT LATER MODEL RUNS BEFORE BLANKETING POPS ANY OR ALL DAYS.
CONFIDENCE IS HIGHER THAT IN MAX TEMPS BEING COOLER THAN WE
PREVIOUSLY THOUGHT...SO VALUES AREA WIDE WERE KNOCKED BACK ABOUT
3-6 DEG EACH DAY. IT IS INTERESTING TO NOTE THAT MODEL SOUNDINGS
FOR MUCH OF NEXT WEEK ARE REMINISCENT OF A MID-SUMMER PATTERN
WITH PRACTICALLY NIL STEERING FLOW AND PWATS OVER 1 INCH DURING
BOTH DAY AND NIGHT. WHERE THIS DIFFERS HOWEVER IS WITH LAPSE RATES
WHICH APPEAR RATHER STEEP AT TIMES LENDING TO AMPLE CAPE AND
SUBSEQUENT CONVECTIVE FEEDBACK CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 95 61 99 61 94 / 30 40 10 10 20
TULIA 95 65 100 65 92 / 30 40 20 10 20
PLAINVIEW 95 67 98 66 93 / 20 30 20 10 20
LEVELLAND 97 65 100 66 96 / 20 20 20 10 10
LUBBOCK 96 69 101 68 96 / 20 20 20 10 10
DENVER CITY 97 65 100 66 97 / 20 20 10 10 10
BROWNFIELD 97 66 101 66 97 / 20 20 20 10 10
CHILDRESS 98 69 102 70 96 / 20 30 20 20 20
SPUR 99 68 102 68 96 / 20 20 20 20 10
ASPERMONT 99 70 101 71 98 / 20 20 10 10 10
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
23
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
101 PM CDT SAT JUN 2 2012
UPDATED AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN UPPER
LEVEL LOW PRESSURE SYSTEM MOVING OVER LAKE HURON. LAST PIECE OF
ENERGY NOW SEEN ROTATING BACK TO THE WEST...NORTH OF THE
LOW...PUSHING CLOUDS AND PCPN BACK TOWARDS NORTHEAST WI. WHERE
CLOUDS REMAIN...OR MOVE INTO...THE TEMPERATURES ARE IN THE 40S OR
LOWER 50S. UNDER CLEAR SKIES OVER CENTRAL AND NORTH CENTRAL WI
TEMPS HAVE FALLEN OFF INTO THE 30S. SMALL PCPN CHANCES TODAY
REMAIN THE MAIN FORECAST CONCERN THIS PERIOD.
STACKED LOW TO LIFT SLOWLY NORTH THROUGH SUN MORNING...DEEPENING
SLIGHTLY THROUGH EARLY THIS MORNING. GIVEN PCPN TRENDS AT THIS
TIME...WILL KEEP SCATTERED POPS GOING...FAR NE AND DOOR COUNTY
THROUGH THIS MORNING...BACKING OFF THIS AFTERNOON AS LOWS
INFLUENCE DIMINISHES. AS IN PAST DAYS...MODELS SHOWING GOOD
INSTABILITY THIS AFTERNOON AND HINT AT WEAK SFC TROF/MOISTURE
CONVERGENCE MOVING OVER CWA THIS AFTERNOON. PROBLEM WITH THIS
FORECAST IS AMOUNT OF DRY AIR...WITH SOUNDINGS SHOWING RATHER DEEP
MIXING FOR GUSTY WEST WINDS AND DEW POINTS DROPPING INTO UPPER
30S TO LOWER 40S. THIS WOULD LIMIT ANY SB INSTABILITY. WILL STAY
WITH MAINLY ISOLD POPS AND LIMIT THUNDER TO SOUTH.
HEIGHTS TO RISE AS RIDGE TO WEST BUILDS IN SATURDAY NIGHT AND
SUNDAY WITH DRY FORECAST EXPECTED.
HAVE HELD TEMPS TO NEAR NORMAL LEVELS TODAY WITH CLOUDS...THOUGH
RETURNING TO ABOVE NORMAL HIGHS ON SUN.
.LONG TERM...SUNDAY NGT THRU NXT FRI. MAIN FCST CONCERN REMAINS
THE EXTENT OF PCPN DURING THE PERIOD AND TRYING TO ATTEMPT TO
ASCERTAIN EXACTLY WHICH DAYS TO FOCUS ON. ANY PCPN APPEARS TO BE
RELATIVELY LIGHT AND SCATTERED AT BEST. TEMPS ARE NOT EXPECTED TO
CHANGE MUCH NXT WEEK WITH READINGS GENERALLY CLOSE TO NORMAL.
MDLS CONT TO INDICATE A MID-LVL PIECE OF SHORTWAVE ENERGY MOVING
THRU THE CNTRL CONUS UPR RDG...THEN DIVING SE THRU THE UPR MS
VALLEY AND INTO THE WRN GREAT LKS/MIDWEST SUNDAY NGT. THERE
APPEARS TO BE A QUASI-STNRY BOUNDARY SITUATED FROM MN S-SE INTO IA
AND THIS BOUNDARY COULD HELP FOCUS THE SHWR POTENTIAL MORE TO OUR
SW IN THE CONVERGENCE ZONE. THIS FEATURE IS NOW A LITTLE SLOWER
THAN LAST NGT`S MDL RUNS...THUS HAVE FOCUSED ANY PCPN TIL AFTER
MIDNIGHT AND PRIMARILY OVER CNTRL WI. THIS DELAY IN PCPN COULD
ALLOW FOR TEMPS TO DROP A COUPLE OF MORE DEGS THAN ORIGINALLY
THOUGHT WITH READINGS AROUND 50 NORTH TO THE MIDDLE 50S CNTRL/
E-CNTRL WI.
WHILE THE SHORTWAVE CONTS TO TREK SE TOWARD THE OHIO RIVER VALLEY
ON MON...THE MDLS SHOW A SHORTWAVE TROF ROTATING SWD THRU THE
GREAT LKS AROUND THE LARGE ERN CONUS UPR TROF. THE COMBINATION OF
THIS TROF WITH DAYTIME HEATING (INCREASING INSTABILITY) WL HELP TO
DEVELOP SOME SHWR ACTIVITY ALONG WITH AN ISOLATED TSTM. MAX TEMPS
WL BE DEPENDENT ON HOW FAST ANY PCPN CAN DEVELOP...THUS READINGS
COULD TOP OUT ANYWHERE IN THE 70S.
THE LOSS OF DAYTIME HEATING AND THE DEPARTURE OF THE SHORTWAVE
TROF WL END ANY LINGERING SHWR THREAT MON EVENING. OTHERWISE...AN
AREA OF CANADIAN HI PRES IS FCST TO BEGIN DROPPING SOUTH INTO THE
GREAT LKS LATER MON NGT BRINGING PARTLY CLOUDY SKIES AND SLIGHTLY
COOLER CONDITIONS. WE WL SEE MIN TEMPS RANGE FROM THE UPR 40S TO
THE MID 50S E-CNTRL WI.
THE HIGHLY AMPLIFIED FLOW ACROSS THE CONUS REMAINS INTACT THRU THE
MIDDLE OF NXT WEEK WITH DEEP UPR TROFS OVER THE WRN U.S./ERN U.S.
AND A NARROW UPR RDG OVER THE MIDDLE OF THE COUNTRY. NE WI TO
RESIDE ON THE ERN SIDE OF THE RDG...BUT ALSO SIT ON THE WRN FLANK
OF THE ERN U.S. UPR TROF. THIS LEAVES THE FCST AREA VULNERABLE TO
ADDITIONAL SHORTWAVE TROFS OR INDIVIDUAL SHORTWAVES MOVING THRU
THE BADGER STATE AND KICKING OFF A FEW SHWRS...ESPECIALLY DURING
THE PEAK HEATING OF THE AFTERNOON. THIS SCENARIO WOULD RUN FROM
TUE THRU AT LEAST THU BEFORE THE UPR RDG SLIDES FAR ENUF EAST TO
POTENTIALLY CAP THE ATMOSPHERE BY THE TIME FRI ROLLS AROUND. DUE
TO THE GENERAL UNCERTAINTY IN TRYING TO TIME EACH OF THESE LITTLE
WEATHER ELEMENTS...HAVE FOLLOWED THE CONSENSUS MDL SOLUTION WHICH
POINTS TO LOW CHC POPS MAINLY DURING THE DAYLIGHT HOURS. AS FOR
TEMPS...READINGS SHOULD BE FAIRLY CONSISTENT DUE TO LITTLE CHANGE
IN AIR MASS. LOOK FOR TEMPS TO END UP CLOSE TO CLIMATOLOGICAL
NORMALS NXT WEEK.
&&
.AVIATION...VFR CONDITIONS TO PREVAIL THROUGH SUNDAY NIGHT. SCATTERED
SHOWERS CAN BE EXPECTED ESPECIALLY NEAR GRB...WEST TOWARD AUW AND
CWA THROUGH ABOUT 3 PM THIS AFTERNOON. AN ISOLATED THUNDERSTORM IS
ALSO POSSIBLE BUT WAS NOT EXPLICITLY INCLUDED IN THE TAFS. THE
BROKEN BAND OF HEAVIER SHOWERS WILL SHIFT SOUTHEAST ACROSS THE
SOUTHERN FOX VALLEY INCLUDING ATW AND OSH BETWEEN ABOUT 2 PM AND
ABOUT 4 PM.
GIVEN THE INSTABLITY...WITH SOME OF THE STRONGER HIGHER-BASED
SHOWERS...THERE MAY ALSO BE A FEW HIGHER WIND GUSTS FROM THE WEST OR
NORTHWEST TO 30 MPH...ESPECIALLY ACROSS EAST CENTRAL WISCONSIN THIS
AFTERNOON.
A FEW LIGHT SHOWERS MAY ALSO LINGER ACROSS THE EASTERN HALF OF THE
FORECAST AREA INTO THE EARLY EVENING...THEN HIGH PRESSURE WILL
GRADUALLY BUILD INTO THE FORECAST AREA OVERNIGHT WITH VFR
CONDITIONS EXPECTED THROUGH SUNDAY.
ESB
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1220 PM CDT SAT JUN 2 2012
.SHORT TERM...THIS AFTERNOON
1220 PM CDT SAT JUN 2 2012
ADDED SCATTERED SHRA/IOSLD T ACROSS PORTIONS OF NORTHEAST IA INTO
FAR SOUTHWEST WISCONSIN FOR THIS AFTERNOON. LATEST RAP SHOWS A BETTER
ORGANIZED MID/SURFACE TROUGH ROTATING SOUTHEAST THROUGH THE AREA
WITH 0-3KM MUCAPE APPROACHING 1500J/KG. APPEARS TROUGH AND
ASSOCIATES SHRA/ISOLD T THREAT WILL BE PUSHED SOUTHEAST OF THIS
AREA BY LATER THIS AFTERNOON IN THE 4-5 PM TIME FRAME.
.LONG TERM...TUESDAY THROUGH FRIDAY
315 AM CDT SAT JUN 2 2012
BOTH THE 02.00Z ECMWF AND GFS BOTH SHOW A SOMEWHAT BLOCKY PATTERN
OVER THE CONUS THROUGH THE PERIOD. TROUGHS WILL BE LOCATED ALONG
BOTH COASTS WITH RIDGING IN BETWEEN. AREA WILL BE ON THE EDGE
BETWEEN THE EASTERN TROUGH AND CENTRAL CONUS RIDGE. SEVERAL SPOKES
OF ENERGY FROM THE EASTERN TROUGH PROGGED TO ROTATE THROUGH THE
GREAT LAKES REGION. THIS WILL BRING PERIODIC SMALL RAIN CHANCES TO
THE AREA. OTHERWISE...TEMPERATURES LOOK TO BE SEASONABLE THROUGH THE
PERIOD.
&&
.AVIATION...THROUGH 18Z SUNDAY
1220 PM CDT SAT JUN 2 2012
CLOSED UPPER LOW OVER THE GREAT LAKES REGION/UPPER MISSISSIPPI
RIVER REGION AND ASSOCIATED COLD AIR ALOFT WILL CONTINUE TO
PRODUCE DIURNAL CUMULUS AT KRST/KLSE TAF SITES THIS AFTERNOON.
THIS CUMULUS WILL DISSIPATE BY SUNSET WITH LOSS OF SURFACE
HEATING. CLEAR SKIES ARE THEN EXPECTED THROUGH THE OVERNIGHT HOURS
INTO EARLY SUNDAY MORNING AS HIGH PRESSURE DRIFTS ACROSS THE
REGION. SOME MID-LEVEL CLOUDS WITH BASES AOA 12KFT ARE EXPECTED TO
SPREAD EASTWARD INTO THE REGION LATER SUNDAY MORNING IN ADVANCE OF
A TROUGH OF LOW PRESSURE OVER THE NORTHERN PLAINS. SHOWERS AND
ISOLATED THUNDERSTORMS ARE EXPECTED TO MOVE ACROSS MN...POSSIBLY
AFFECTING THE KRST TAF SITE LATE SUNDAY AFTERNOON.
OTHERWISE...PLAN ON VFR CONDITIONS THROUGH 18Z SUNDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
315 AM CDT SAT JUN 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...JLR
AVIATION...DAS