Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 08/20/24
Area Forecast Discussion
National Weather Service La Crosse WI
1102 PM CDT Mon Aug 19 2024
.KEY MESSAGES...
- Low chances (10 to 15%) of showers for the first half of the
week. Subsequent precipitation chances (20 to 30%) Thursday
night into Friday.
- Temperatures stay slightly below normal for much of the week,
increasing to 5 to 10F above normal for the weekend.
&&
.DISCUSSION...
Issued at 232 PM CDT Mon Aug 19 2024
Today through Friday:
Smoke will be in the area today and tonight. This will make skies
hazy for today. Not expecting much if any of the smoke to reach the
surface. Some visibility restrictions could be possible if the smoke
concentration increases. Looking at the synoptic pattern, ridging
will be in place through the weekend. During the week the area will
be influenced by a low that continues to move on to the northeast.
The ridge axis will stay off to the west and as a result, instead of
warm southwesterly flow pushing into the region, low-level easterly
flow will remain in place for most of the week. This will help to
keep temperatures at or slightly below normal.
With this flow pattern, a backdoor cold/dry front will move through
the Upper Midwest during the first part of this week. Isolated
showers, associated with this front and influence from the low-
level easterly flow, are possible this afternoon and evening
across central Wisconsin, however there is some uncertainty
regarding these showers when looking at model soundings as there
is quite a bit of dry air in the lower levels. Heading into
Tuesday, this front will stall over southeastern Minnesota and
northeastern Iowa. Isolated showers have popped up in some more
of the short term models, however due to some uncertainty and
drier air, have continued with what the previous discussion
mentioned and did not put an PoPs at this time.
By the middle of the week, a shortwave will move into the region.
The uncertainty revolves around how far east the disturbance and
moisture goes on Wednesday. Some models show some precipitation
chances on Wednesday, however there is a lot of uncertainty with the
precipitation on Wednesday. This shortwave does eventually push east
Thursday into Friday and increases the precipitation chances for the
Upper Midwest. After this shortwave exits, the next precipitation
chance looks to be early next week.
The Weekend and Early Next Week:
Heading into the weekend, the low that is currently moving towards
the northeast will move far enough away to loosen the influence it
has over the region. Easterly low-level flow will transition to
southwesterly flow as the ridge pushes east and amplifies. With the
stronger ridge, temperatures are expected to increase to 5F to 10F
above normal, resulting in high temperatures ranging from the
mid 80s to near 90F. After the weekend, models diverge on what
will take place. A low looks to move into the Intermountain West
and push off to the northern Plains. There remains uncertainty
on if this impact the Upper Midwest. Ensemble guidance favors a
more zonal approach to early next week, which may help to
increase precipitation chances.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1102 PM CDT Mon Aug 19 2024
Fog/low-stratus will be the primary aviation concern this morning
with falling dewpoint depressions and light surface winds with
surface high pressure still in place. The main questions will be how
a stronger near-surface wind layer per the recent RAP will influence
any fog formation. With a backdoor front nudging its way into the
region towards daybreak tomorrow as well, starting to notice a trend
in the 20.00z HREF cig probabilities (50-70%) which show a IFR
stratus layer moving through from east to west across southeast MN.
Consequently, have introduced a tempo for IFR cigs at KRST. Overall
a very challenging forecast with mixed signals, lower dewpoint
depressions at KLSE would favor fog formation so decided to
introduce category reductions at KLSE, however with questions
related to the near-surface wind layer and wildfire smoke aloft, did
not introduce IFR visbys at this time but may need to amend
overnight if trends continue to favor fog formation.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&
$$
DISCUSSION...Cecava
AVIATION...Naylor
Area Forecast Discussion
National Weather Service Columbia SC
837 PM EDT Mon Aug 19 2024
.SYNOPSIS...
A few showers or thunderstorms are possible today, mainly north and
west of Columbia. Drier air moves into the region for much of
the week with a cooling trend through Friday. The next chance
for rain for parts of the forecast area occurs late in the week,
with warmer temperatures this weekend.
&&
.NEAR TERM /UNTIL 8 AM TUESDAY MORNING/...
Key Message(s):
- Some isolated showers possible through the early overnight
hours.
A deep trough remains in place across the eastern US this
evening, which helping trigger some isolated showers and
thunderstorms across the Midlands thanks to steep mid-level
lapse rates. Given the steep lapse rates, some elevated
instability will remain overnight even after diurnal heating has
ceased, so some PoP`s will linger overnight through 0800z; the
HRRR has consistently pointed to some showers developing in the
CSRA and western Midlands overnight as a 500mb vort max lobe
swings down and acts on the elevated instability and overall
there`s no reason to discount this.
&&
.SHORT TERM /8 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
Key Message(s):
- Drier air filters into the area as a cooling trend begins.
Troughing continues to build south through midweek. Surface high
gradually consolidates over the Great Lakes and translates toward
New England. This will drive drier air into the region from the
north, with PW values between 1" and 1.25" and dewpoints mixing into
the upper 50s to low 60s during the day. A few showers may encroach
on the Southeast Midlands from buildups along the sea breeze, but
should generally remain out of our area. Daytime temperatures cool a
bit each day through the mid 80s with lows in the 60s.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
Key Message(s):
- Mostly dry conditions and cooler temperatures continue through
Friday.
Southern trough axis splits from the mean trough and cuts off over
the GoM. This should allow better moisture return on both easterly
winds at the surface with high pressure to the northeast, and aloft
with southwest flow at H5 and above. Lingering surface front moves
back toward the SC coastline with a few shortwaves rotating through
the mid and upper flow. The threat for precip then returns mainly to
the eastern Midlands toward the Coastal Plain, but we`ll need to
monitor trends this week to see if areas further inland could also
see some showers and thunderstorms each afternoon from Thursday
through this weekend. Temperatures remain in the low to mid 80s
Thursday and Friday, but with the breakdown of the upper ridge we`ll
see a slight uptick in these values for the weekend.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
VFR conditions expected through the TAF Period.
Some lingering isolated convection moving into the forecast area
late this evening, driven by a shortwave moving through the base
of the upper trough. Expect isolated showers to diminish by
around 06z or so. Cannot totally rule out some rain reaching
CAE/CUB but will handle with amendments if needed due to
isolated nature. Winds should be light and variable to near calm
overnight then pick up from the northeast after 12z at around 5
to 7 knots through the day. Some guidance suggesting possible
brief period of low clouds at OGB but confidence is not high
enough to include at this time.
EXTENDED AVIATION OUTLOOK...No significant impacts to aviation
expected.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...None.
GA...None.
&&
$$
Area Forecast Discussion
National Weather Service Dodge City KS
508 PM CDT Mon Aug 19 2024
.KEY MESSAGES...
- Cooler temperatures are likely today and tomorrow behind the
recent cold front.
- Sub-severe thunderstorms are possible tonight, mainly along
and north of US-50.
- Mostly dry, warming trend is expected Wednesday through the
weekend.
&&
.DISCUSSION...
Issued at 200 PM CDT Mon Aug 19 2024
Water vapor satellite imagery and RAP upper air analysis at 19Z
Monday showed a large, cut-off mid-level ridge centered over the
southern plains, with a pair of troughs on either side. At the
surface, easterly winds are in place across southwest KS in the
wake of the recent cold frontal passage. This has brought
abundant low clouds and much cooler temperatures to our area
after yesterday`s record-setting heat, and afternoon highs will
only range from the mid 80s near I-70 to the mid 90s along the
KS/OK border. Later tonight, latest HREF suggests scattered
showers and a few thunderstorms will emerge from eastern CO and
roll across southwest KS, with probability of QPF > 0.1" in the
40-60% range along and north of US-50. Thankfully, very weak H5
flow will render this activity sub-severe, only posing a heavy
rain and frequent lightning threat.
Daytime Tuesday, short range ensembles agree the upper level
pattern will be virtually static, with the large mid-level ridge
fixed firmly above the southern plains. As a result, little to
no change in the sensible weather is expected, and afternoon
highs will once again range from the mid 80s near I-70 to the
low/mid 90s near the KS/OK border. There is an outside chance
(~10%) of another round of thunderstorms emerging from eastern
CO and affecting our far west/southwest zones, but most HREF
members keep all convection outside our area, and in response
the inherited dry forecast was maintained.
Wednesday through the end of the period, medium range ensembles
indicate the synoptic pattern will remain relatively unchanged
as the mid-level ridge moves slightly northeastward and expands.
As a result, a gradual warming trend is expected with afternoon
highs rising from the low/mid 90s on Wednesday back into the
upper 90s/low 100s by Friday through the weekend. While chances
for precipitation exist during this period favoring the northern
zones, mainly Wednesday and Thursday evening as a few mid-
level vorticity maxima crest the ridge, LREF probability of QPF
> 0.01" only reaches the 10-30% range, so the slight chance pops
(15-24%) in the forecast those nights may be overdone.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 503 PM CDT Mon Aug 19 2024
VFR conditions will prevail for all TAF sites through the TAF
period. Storms during the overnight in the western CWA are not
expected to impact the TAF sites beyond an increase in cloud
cover. 10-15 KT winds are expected to continue from the
southeast through the period.
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION...Springer
AVIATION...KBJ
Area Forecast Discussion
National Weather Service Quad Cities IA IL
620 PM CDT Mon Aug 19 2024
.KEY MESSAGES...
- Wildfire smoke is expected to increase over the area this
afternoon and evening, with most of the smoke above the
surface. The smoke may mix down to ground level at times and
lead to slight reductions in visibility.
- Seasonable temperatures and mainly dry conditions are
forecast this week.
- More summer-like heat and humidity returns by the weekend and
continues into next week.
&&
.SHORT TERM /THROUGH TONIGHT/...
Issued at 200 PM CDT Mon Aug 19 2024
A large area of high pressure situated over Ontario into the
Great Lakes region has led to quiet weather locally today with
temperatures a little below mid/late August normals; early
afternoon temperatures were in the mid to upper 70s. Wildfire
smoke, mainly aloft, will continue to overspread the area from
north to south along the eastern periphery of an upper level
ridge. Some of the smoke may mix down to the surface this
afternoon and evening, which could temporarily drop visibilities
under 6 miles. However, anticipate the near surface
concentrations to remain fairly low.
A brief isolated shower or occasional sprinkles are possible
across the southeast counties this afternoon, where daytime
heating has yielded a few hundred J/kg of mixed layer CAPE and
a narrow corridor of agitated CU is present on visible
satellite. Included a slight chance (~15%) for showers in this
part of the forecast area through mid afternoon. For tonight expect
dry conditions, light winds, and lows in the 50s.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
Issued at 200 PM CDT Mon Aug 19 2024
Tuesday through Thursday, the high pressure from Canada will be
most influential over the area, with dewpoints finally dropping
the lower to mid 50s, as well as overnight lows then reaching
the upper 40s to lower 50s...Windows Open Weather! Highs in the
mid to upper 70s Tuesday and Wednesday will only rise to the
upper 70s Thursday.
High pressure is forecast to shift to the east by Friday, with
a warm up to the lower to mid 80s, then mid to upper 80s
Saturday, followed by upper 80s to low 90s Sunday and Monday.
This period of warmth continues through late August.
Above normal temperatures are likely (70-80%), per CPC 6-10 Day
Outlook, for the period from next Saturday through Wednesday
August 28. Normally during this time, highs are in the upper 70s
to low 80s. CPC also indicates precipitation will be leaning
below average (33-40%) during this time with dry conditions
persisting locally and even more so to the southeast in the Ohio
Valley. The NBM has occasional low chances (20%) for showers
and thunderstorms from Friday night through next Monday, but
much of the outlook area is likely to stay dry during this time.
&&
.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 620 PM CDT Mon Aug 19 2024
VFR conditions are largely expected through the TAF period. The
main focus continues to be on lingering wildfire smoke, which
is expected to mix down to the surface tonight at least in a
small amount. The latest RAP and HRRR models show some slight
differences in the timing of the higher smoke concentrations,
but it appears most likely for DBQ and CID to have MVFR
visibilities from haze. MLI and BRL are a bit more uncertain on
the impacts to vsbys. Otherwise, another round of daytime
cumulus clouds are expected to develop Tuesday, with east to
northeast winds around 5 to 10 knots.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.
&&
$$
SHORT TERM...Uttech
LONG TERM...Ervin
AVIATION...Schultz
Area Forecast Discussion
National Weather Service Flagstaff AZ
722 PM MST Mon Aug 19 2024
.SYNOPSIS...Expect isolated to scattered showers/thunderstorms
today and Tuesday, with greatest coverage across higher terrain.
An increase in monsoon activity will arrive by mid-week and stick
around through Friday. Above normal temperatures anticipated
through tomorrow, with a slight cooling trend beginning on
Wednesday.
&&
.UPDATE...No major forecast updates are needed this evening as
most of the convective showers and storms are diminishing with the
setting sun. A few lingering showers remain, and will remain
possible through the evening hours. Overall, a quiet night is
anticipated with overnight lows similar to last night.
&&
.PREV DISCUSSION /403 PM MST/...Cloud cover as well as a few
isolated showers/storms have started picking up across the higher
elevation areas. Although overall instability and shear is on the
weaker side for today, daytime heating from the clear
morning/early afternoon conditions has assisted with the
thunderstorm development so far and will continue to do so through
the rest of the afternoon and evening. Majority of convective
activity should dwindle after sunset, but the HRRR is hinting at a
few stray showers across Apache County late this evening.
Tomorrow will likely be a wash, rinse, repeat of today. Expect
isolated to scattered showers/thunderstorms with the greatest
probabilities across the higher terrain. Winds will generally be
5-15 mph today and tomorrow, minus any gusty outflow driven winds.
Outside of precipitation chances, high temperatures look to land
in the 2-10 degrees above normal range. The increase in
temperatures and the decline in showers/thunderstorms is due to a
dominating high pressure system that is centered over New Mexico
and gradually expanding westward through tomorrow.
Wednesday through Friday...The previously mentioned ridge will be
pushed eastward as a long-wave trough shimmies down the West
Coast. This will tighten pressure gradients across much of our CWA
and create a saturated southwesterly flow. As a result, chances
for showers and thunderstorms quickly ramp up Wednesday through
Friday. Hi-res guidance also suggests overnight showers and
thunderstorms Wednesday into Thursday, so don`t be too surprised
if activity doesn`t completely shut-off in the late
evening/overnight hours. Daytime highs look to cool by 5-10
degrees, bringing temperatures below normal for this time of year.
One last tidbit to note with this strong low, the tightening of
the pressure gradients will bring increased wind speeds gusting
near 20-30 mph both Thursday and Friday. These gusty conditions
will be outside of any storm development, but we could see
stronger gusts near outflows.
Over the Weekend...Model guidance suggests the long-wave trough
will push inland and possibly bring drier conditions. There is
still a lot of uncertainty with how this trough will ultimately
impact northern Arizona, so check back later for more details.
&&
.AVIATION...Tuesday 20/00Z through Wednesday 21/00Z...Isolated to
scattered SHRA/TSRA will continue through 02Z-04Z, mainly over
the higher terrain. Storm motion toward the north-northeast 10-15
kts. Brief periods of MVFR and gusty winds possible near +RA/TS.
Otherwise, VFR conditions with SW winds 5-10 kts. Another round of
isolated to scattered SHRA/TSRA is forecast after 19Z Tuesday.
OUTLOOK...Wednesday 21/00Z through Friday 23/00Z...On Wednesday
and Thursday, much higher coverage of SHRA/TSRA is forecast, even
during the overnight period Wednesday night. Outside of storms,
VFR conditions with SW winds around 10 kts.
&&
.FIRE WEATHER...Rest of today through Wednesday...Isolated to
scattered showers and thunderstorms expected today and Tuesday,
mostly confined to the higher elevations. Expect a quick ramp up in
convective activity Wednesday that will likely persist into the
overnight hours. Outside of gusty/erratic storm driven winds,
generally light winds 5-15 mph. Above normal temperatures through
Tuesday before slightly cooler conditions return mid-week.
Thursday through Saturday...Chances for showers and thunderstorms
will persist through Friday, becoming limited to eastern AZ and
higher elevation areas on Saturday. Expect elevated winds on Friday
and Saturday gusting near 20-30 mph, but strong winds from outflows
likely both Thursday and Friday. Below normal to near normal
temperatures anticipated through the period.
&&
.FGZ WATCHES/WARNINGS/ADVISORIES...None.
&&
$$
PUBLIC...MCT/Konieczny
AVIATION...RR
FIRE WEATHER...Konieczny
For Northern Arizona weather information visit
weather.gov/flagstaff
Area Forecast Discussion
National Weather Service Green Bay WI
1051 PM CDT Mon Aug 19 2024
Updated aviation portion for 06Z TAF issuance
.KEY MESSAGES...
- Hazardous conditions for small craft are expected tonight on the
Bay and Lake Michigan.
- Other than a low chance of rain on Thursday night and Friday,
quiet weather is forecast for the next week. Temperatures will
be around five degrees below normal through Thursday, and be
five to ten degrees above normal by Saturday,.
&&
.DISCUSSION...
Issued at 359 PM CDT Mon Aug 19 2024
Short Term...Tonight and Tuesday
Mainly quiet conditions are expected for this forecast period with
the exception of a few sprinkles possible this afternoon and breezy
northeast winds late this afternoon and evening.
Precipitation...A weak boundary will continue to drop southwest over
northeast WI into central WI through this evening. This afternoon`s
satellite imagery showed clouds developing and expanding in
association with this boundary over central WI, which coincided with
a shallow moisture layer mainly between 850mb and 700mb in RAP
analysis soundings. While some CAMs continue to show isolated light
showers or sprinkles developing this afternoon and evening, others
remain dry. Based on cloud trends and how shallow of a moisture
layer the boundary is working with, considered going completely dry
this afternoon and evening, but instead decided to leave a mention
of isolated sprinkles in the forecast due to the present boundary
and bay/lake breezes providing the needed lifting mechanism. Any
sprinkles will come to an end this evening. A very low chance for
sprinkles may occur again towards Tuesday morning along the
lakeshore as an onshore wind is expected and delta Ts will be
between 15-17. If sprinkles don`t develop, at least anticipate
clouds to move inland from Lake MI Tuesday morning and shift into
east-central WI for the afternoon.
Winds and Marine...Sustained north to northeast winds of 10 to 15
mph and gusts to 25 mph on the Bay this afternoon have coincided
with the Small Craft Exercise Caution nicely. Anticipate these winds
to continue through this evening, so did not make any changes to the
Exercise Caution. Although winds are still forecast to remain below
Small Craft Advisory criteria on Lake MI, the onshore wind will
generate criteria waves of 3 to 5 ft, mainly south of Sturgeon Bay.
Therefore, did not make any changes to the Small Craft Advisory in
effect. Light winds are expected across the (land) forecast area for
tonight into Tuesday.
Fog and Temperatures...Light winds and mostly clear skies overnight
will not only lead to cooler temperatures, but also possibly patchy
fog development mainly across north-central WI. Lows tonight will
range from the low 40s to low 50s, but a few of the typical cold
spots may see values in the upper 30s. Any fog would burn off a few
hours after sunrise into Tuesday morning. The cooler air flowing
from the north/northeast on Tuesday will lead to less humid
conditions and highs below normal, ranging from the low to mid
70s.
Long Term...Tuesday Night Through Monday
Beautiful summer weather is expected through the end
of the week, as a surface high moves slowly from the Great Lakes
to the Middle Atlantic States. There is a small chance of a
shower or thunderstorm Thursday night or Friday, as an upper
trough moves around the upper ridge.
Temperatures will be around five degrees below normal through
Thursday, and warm to 5 to 10 degrees above normal by Saturday.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1049 PM CDT Mon Aug 19 2024
Skies will be mostly clear much of the night, but northeast winds
and cooler air flowing across Lake Michigan will result in lower
VFR lake clouds at MTW into mid morning on Tuesday. Also, some
patchy ground fog could occur late tonight especially north-
central WI, though gradient wind just off sfc may keep limit this
potential. Expect clouds near Lake Michigan to transition to a
scattered-broken cu field farther inland by Tuesday afternoon.
Diurnal clouds clear out late day with scattered cirrus arriving
from the west.
Winds will mainly be out of the north/northeast under 10 kts
through Tuesday afternoon, with only a few higher gusts at times
into the overnight as cooler air initially arrives across the bay
and Lake Michigan.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
DISCUSSION.....Kruk/RDM
AVIATION.......JLA
Area Forecast Discussion
National Weather Service Gray ME
1151 PM EDT Mon Aug 19 2024
.SYNOPSIS...
Showers and storms gradually diminish into early tonight as a
frontal system crosses through. Long period swell from distant
Ernesto will peak this evening bringing high surf and a rip
current risk. An upper level low pressure system dropping out of
Canada will linger over New England through the balance of the
week followed by high pressure building in towards the end of
the week.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
1145 PM Update...Precipitation shield across western ME will
continue to push off to the east over the next couple of hours.
Very downpours and lightning remain possible with the activity,
especially toward the Midcoast where rain rates could still
exceed 2" per hour and produce some ponding of water on
roadways. Farther north, rain rates are much lower, but there
still could be a few showers develop from time to time. Update
was mainly to freshen up the PoP/wx grids based on latest
trends.
630 PM UPDATE...A slow-moving line of heavy thunderstorms is
currently moving across New Hampshire. PWATs near 1.70 inches
and 1200J of CAPE in a low-shear environment will likely
continue the gusty wind and heavy rainfall risk within this line
of storms at least until 10PM. With night time approaching and
storms nearing the marine layer, it should be difficult for
storms to hold together near the coast and really anywhere east
of Lewiston, ME. Opted to remove any enhanced wording after
10PM. Blended temperatures with observations, and worked in the
most recent NAM3k to more accurately capture the temperature
trend we`re currently experiencing.
PREVIOUSLY...There remains quite a bit of moving parts to the
near term portion of the forecast for tonight. A continuing
moisture rich environment remains over the region with high
surface dew points and PWATs in place. One band of showers will
graze coastal areas for the rest of the afternoon and evening
associated with a weak trough of low pressure that contributed
to the flooding in southern New England yesterday. These showers
may be relatively slow moving and can produce locally heavy
rainfall.
A second band of more organized convection will exit out of
Vermont early this evening in association with a large upper
level low and a frontal system digging southward towards New
York State and into New England. The latest HRRR continues to
bring this band into the Connecticut River Valley by 21Z with
additional showers breaking out ahead of this broken line. There
remains signatures with the HREF solution suggesting the
potential for high rainfall rates. Will include the threat of
very heavy rainfall to the forecast through the first half of
tonight for New Hampshire and portions of western Maine which
essentially are the same locations discussed in WPCs Excessive
Rainfall Outlook.
Have also include gusty winds in the forecast through this
evening in any organized convection, particularly over New
Hampshire where the greatest instability remains situated. This
is in good agreement with SPCs marginal risk.
Plenty of low level moisture and recent rainfall to include
another night of patchy dense fog. This was relatively
widespread last night in some sections.
Splash-over and minor coastal flooding will likely occur
tonight. Please see discussion below for details.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY/...
The vigorous upper level low continues to dig south into New
York State Tuesday and Tuesday night. At the same time, a couple
waves of low pressure will develop along the front system over
the coastal waters. This will bring more showers and a few
thunderstorms to the region. The highest pops will be located in
the mountains. Temperatures will remain seasonably cool during
the day due to the cloud cover.
An interesting surface trough may develop by Tuesday night as
well. This trough takes on characteristics similar to a winter
time Norlun trough with a convergent low level low setting up.
Fog will not be as prevalent Tuesday night with slightly drier
air entering the forecast area.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
Overview: To start the forecast period, large stacked low
pressure will slowly push into the Northeast Wednesday, pulling
east through late week. This will be responsible for unsettled
conditions Wed and Thursday before drier northwest flow arrives
Friday. Temperatures run a few degrees below normal, before
pushing higher this weekend.
Details: Descending upper trough early this week slowly becomes
cutoff drifting into the Northeast. Best moisture transport
will be deflected well east of this approaching low, meaning
overall PWAT and moisture parameters are pretty marginal through
the Wed and Thurs time period. This wont stop the chance for
daily showers however. Common with these broad, slow moving lows
is a lower freezing level. Daytime heating and this low frz
level usually yields shallow convection with showers and periods
of rain. This is supported by majority of guidance packages
this afternoon. Question will be how much does the lower
moisture content and potentially cooler than normal surface
temps impact the coverage of showers. Confidence is higher in a
cloudy mid week all things considered, dominated by mid to low
clouds spreading out as afternoons go on.
With the cooler temps and breeze aloft, could see some wind
chills dip towards freezing at the higher summits as fcst temps
there fall towards the mid to upper 30s. These will mainly be in
the region mid week as the low is centered overhead. Its that
time of year where summit weather will occasionally be quite
different than at trail head (particularly temperature
differential). Best to wear your layers and turn back if not
prepared for changing conditions!
Drier, warmer trend is set for the weekend if the low pushes
east on time. Beginning Friday, NW flow should tap into drier
air behind the departing low. The drier air should provide more
in the way of sun for Fri and Sat, also bumping temps up through
the weekend.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Short Term...Showers, scattered thunderstorms and patchy dense
fog will make for LIFR conditions at times across much of the
region as we go through the night tonight. Conditions will be
slow to improve Tuesday morning with MVFR conditions.
Long Term...An extended period of MVFR/IFR cigs is possible Wed
and Thurs along with SHRA, mainly towards the mountains of
NH/ME. This may also move into the foothills/interior, but may
be more diurnal based. General improvement towards VFR is
expected for Friday and the weekend.
&&
.MARINE...
Short Term...A long period swell from Ernesto will continue
tonight with high surf as well. Have extended the SCAs for the
outer waters as seas remain high into Tuesday evening.
Long Term...Broad upper low pressure will reside across the
region mid week. This slowly pushes northeast towards late week,
with general clearing into the weekend. Conditions likely remain
below SCA through the period, with waves decreasing into the
weekend.
&&
.TIDES/COASTAL FLOODING...
Expect up to a one foot storm surge tonight with large breaking
waves. Splash-over and possibly minor coastal flooding can be
expected, mainly from Portland and points south along the coast.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...Coastal Flood Advisory until 1 AM EDT Tuesday for MEZ023-024.
NH...Coastal Flood Advisory until 1 AM EDT Tuesday for NHZ014.
MARINE...Small Craft Advisory until 10 PM EDT Tuesday for ANZ150-152-
154.
Small Craft Advisory until 6 AM EDT Tuesday for ANZ151-153.
&&
$$
Update...Combs
Area Forecast Discussion
National Weather Service Newport/Morehead City NC
751 PM EDT Mon Aug 19 2024
.SYNOPSIS...
A cold front will move across the Carolinas this evening
bringing a threat for unsettled, and potentially severe,
weather to the area. High pressure then builds in from the
north and west Tuesday through late week once again bringing
drier and cooler weather to the region. Coastal showers may
affect the Crystal Coast late in the week into the weekend.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
As of 8 PM Mon...More organized storm threat will be this
evening, where a marginal risk still stands. Best chance for a
severe storm will be nrn zones, where NCAR HRRR neural network
probs are up to 20% for severe after 23Z with the front to the
west approaching. The window will be short, as by midnight, sct
showers/storms will shift offshore with winds turning nrly
behind the front. Temps will cool into the 60s interior to near
70 coast, climo for this time of year.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
As of 3 PM Monday...The aforementioned cold front is forecast
to reach the Crystal Coast and stall due to differential heating
forcing a sea breeze. The sea breeze should be confined to the
immediate coast. This could act as a focus for some iso/sct
showers and may be a few storms later afternoon. Elsewhere,
nrly flow and TD`s well down into the 60-65 degree range will
bring pleasant and dry conditions.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
As of 350 AM Mon...Cooler and drier weather settles over the
area for the remainder of the work week, with some modest shower
and thunderstorm chances over the weekend as moisture from the
stalled frontal boundary struggles to crawl back northwards.
Tuesday through Thursday...Cooler and much drier high pressure
settles over the eastern CONUS behind the cold front as it
continues to sag southwards. Temperatures will struggle to
breach the low 80s for many spots, sitting a good 5-10 degrees
below average for late August. Additionally, with multiple
nights of clear skies and near calm winds excellent radiational
cooling is likely for at least a couple nights, especially Tues
and Wed. With afternoon Tds falling into the mid 50s, overnight
lows will near similar values. Did raise temps a bit along the
immediate coast, fearing the influence of very warm waters may
modify the near-shore airmass enough to spoil cooler temps. Record
lows will be threatened, particularly Wednesday evening. See
CLIMATE section for previous records.
Friday through Sunday...The NNE flow becomes easterly, with
some shallow moisture and clouds returning. Capped PoPs at
slight chance and confined to the immediate southern coast, in
line with the previous forecast. Temps return to near climo
with the erly flow and higher TD`s, with highs up to the mid 80s
and lows in the 60s Fri into Sun.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /through Tuesday Afternoon/...
As of 8 PM Mon...Mostly VFR conditions are present early this
morning across the airspace, though areas of convection moving
in from the NW will likely bring periods of sub-VFR conditions
to the coastal plain east to the NOBX, and possible as far south
as around New Bern. Convection will dissipate quickly around
midnight, and a cold front will push into ENC from the north
overnight. This will bring the potential for low stratus
developing as moisture gets trapped in the low levels. Current
confidence in this potential is low, so will not include any low
ceilings in the TAF, but there is potential for IFR ceilings to
develop early tomorrow morning before dry air wins out. Whatever
low clouds that are left over tomorrow morning will quickly
dissipate and VFR conditions are expected through tomorrow
afternoon.
LONG TERM /Tuesday night through Friday/...
As of 350 AM Mon...Drier weather from Tue and beyond as high
pres builds in from the NW. May be some radiation fog each
morning with T-TD spreads very low each morning with the high in
place.
&&
.MARINE...
SHORT TERM /through Tue/...
As of 3 PM Mon...Seas have subsided below 6 ft, thus ending the
SCA`s that were in effect. Swrly flow becomes nw then nrly
tonight through Tue behind the front, though speeds only 10-15
kt and seas 2-4 ft.
LONG TERM /Tuesday night through Friday/...
As of 355 AM Sun...Front will be well offshore by Tues morning
with winds becoming nwrly, then nrly to nnerly Tue into Thu as
high pres builds from the nw. Speeds will generally be in the
10-15 kt range with some gusts around 20 kt especially Wed and
Thu. Raleigh and Onslow Bays may approach SCA criteria during
these two days, otherwise no hazardous marine weather is
anticipated for the long term.
&&
.CLIMATE...
Record Low temps for 08/22 (Thursday)
LOCATION TEMP/YEAR
New Bern 62/1998 (KEWN ASOS)
Cape Hatteras 62/1998 (KHSE ASOS)
Greenville 50/1969 (COOP - Not KPGV AWOS)
Morehead City 58/1998 (COOP - Not KMRH ASOS)
Kinston 56/2000 (COOP - Not KISO AWOS)
Jacksonville 62/1998 (NCA ASOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...Beach Hazards Statement until 8 PM EDT this evening for NCZ195-
196-199-203>205.
MARINE...None.
&&
$$
SYNOPSIS...MHX
NEAR TERM...TL/SGK
SHORT TERM...TL
LONG TERM...CB/MS
AVIATION...SGK/MS
MARINE...TL/MS
CLIMATE...MHX
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
1040 PM CDT Mon Aug 19 2024
.KEY MESSAGES...
- A few chances of isolated showers this afternoon and again
Tuesday afternoon.
- Rain chances increasing for Thursday night into Friday.
- Warmer and muggier this weekend.
&&
.DISCUSSION...
Issued at 251 PM CDT Mon Aug 19 2024
Fairly quiet this afternoon with temperatures ranging in the mid to
upper 70s with light variable winds. Surface high pressure currently
exists over southeastern MN and western WI which has suppressed much
of the cloud cover this afternoon in those areas. The same cannot be
said about west-central MN region where a weak surface low is
generating some patchy pockets of agitated cumulus. Reflectivity is
returning a few isolated weak echoes between Alexandria and St.
Cloud this afternoon but likely falling is virga given drier air
advecting from the south. Coverage should continue to remain
isolated at best for any showers that can reach the surface through
this afternoon and dissipate this evening. Wildfire smoke continues
to linger aloft and is expected to for the next few days. With weak
flow aloft, lingering smoke will allow for haze to develop through
at least midweek. Tonight`s forecasted lows will reach the lower 60s
with partly cloudy skies.
Tuesday through Monday... By Tuesday, a mid-level wave develops over
the eastern Dakotas and tracks east-southeastward. Overall forcing
for this wave does not look impressive as forecast RAP soundings
showing elevated instability and a mostly dry boundary layer. Couple
this will meager forcing, expecting and precip coverage to once
again be isolated to scattered at best Tuesday afternoon. Highest
confidence for more organized development remains west of MN which
aligns with latest HREF guidance. High pressure begins to erode and
depart east by Thursday allowing for flow to transition to a zonal
pattern. Long-term guidance continues to return a broad spread of
shower and thunderstorm chances across the upper-midwest Thursday
into Thursday night. With disagreement amongst the CAMS, decided to
maintain Chc PoPs within the 30 percents through this period.
By this weekend and just in time for the State Fair, conditions
will be warmer and muggy. Forecasted temperatures earlier in the
week will increase from the low to mid 80s to the upper 80s
with dew points in the 60s by Sunday. Another system looks to
approach from our west late Sunday into Monday which will return
highs into the lower 80s.
&&
.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1040 PM CDT Mon Aug 19 2024
VFR conditions through the period. Increasing mid level clouds
expected Tuesday with light or calm winds tonight becoming
southeast 5-10 kts by late morning. Some showers are possible
late in the period across western MN, which has necessitated the
introduction of Prob30s.
KMSP...No additional concerns.
/OUTLOOK FOR KMSP/
WED...VFR. Wind SSE 5-10 kts.
THU...VFR. Wind S 10-15 kts.
FRI...VFR. Wind S 10-15 kts.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.
&&
$$
DISCUSSION...Dunleavy
AVIATION...Borghoff
Area Forecast Discussion
National Weather Service Norman OK
941 PM CDT Mon Aug 19 2024
...New AVIATION...
.KEY MESSAGES...
Updated at 939 PM CDT Mon Aug 19 2024
- Dangerous heat continues across southwest Oklahoma and western north
Texas through most of the week.
- Elevated fire weather conditions are possible across southwest
Oklahoma and north Texas most afternoons this week.
&&
.SHORT TERM...
(This evening through Tuesday)
Issued at 234 PM CDT Mon Aug 19 2024
A frontal boundary lays draped across Oklahoma from about Ellis
county southeast down to McClain county. The boundary extends
further southeast, albeit a bit more diffuse. Temperatures on the
north side of this boundary are running about 5 to 15 degrees cooler
than yesterday, with the largest drops seen over northern Oklahoma.
Meanwhile, much of southwest Oklahoma and western north Texas and
parts of far south central Oklahoma continue to bake with heat
advisories in place.
We`ll be watching the frontal boundary again this afternoon and
early evening for signs of "surprise" storms, though the environment
looks a little less volatile today (1000-2000 joules CAPE, 20-30
knots of deep layer shear). Still, can`t rule out a few isolated
cells (10% chance) with the potential to produce a severe downburst.
Models depict a storm complex coming down off the high plains again
tonight, with a low chance (10-20%) of impacting our northeastern
counties (by which point, it should be mostly just showers).
Tomorrow, heat will continue across southwest Oklahoma and western
north Texas (heat indices in the 103-108 degree range), while the
rest of the forecast area enjoys slightly cooler weather (all the
way down to the low 90s in north central Oklahoma).
RH values are again expected to fall below 20%, coincident with ERC
values in the 80th to 90th percentile range, in parts of southwest
Oklahoma and western north Texas (leaning heavily on the HRRR for
dewpoints in this area as deep mixing is expected). This will be
mitigated somewhat by light winds (generally less than 10 mph).
Day
&&
.LONG TERM...
(Tuesday night through next Sunday)
Issued at 234 PM CDT Mon Aug 19 2024
...Heat continues southwest Oklahoma and western north Texas.
A tight gradient between temperatures in the triple digits across
southwest Oklahoma and western north Texas and temperatures in the
90s across the northeast half of Oklahoma will persist through mid
week. Friday and Saturday, triple digit temperatures start to spread
back over the region as the upper ridge moves back over us.
...Elevated fire weather continues in southwest Oklahoma and western
north Texas this week.
The low RH / light wind pattern will continue through much of the
week for western and southwestern parts of the forecast area,
coincident with ERC percentiles in the 70-90th range. Note that
global models tend to struggle with the magnitude of dryness in
these patterns.
...Rain chances remain minimal through at least Friday.
The dominating upper ridge will keep most rain chances outside of
our forecast area through at least Friday. There`s some signal in
the deterministic models that the pattern may start to shift this
weekend, but probabilistically the chance for rain Saturday / Sunday
remains below 10%.
Day
&&
.AVIATION...
(00Z TAFS)
Issued at 939 PM CDT Mon Aug 19 2024
Showers/storms in the High Plains could move into parts of north
central OK early Tuesday although chances too low for mention in
TAF at this time. Otherwise forecast is dry. VFR ceilings are
expected with mid and high clouds. Winds will generally be from
the E and SE this TAF period.
&&
.PRELIMINARY POINT TEMPS/POPS...
Oklahoma City OK 73 92 73 92 / 0 0 0 0
Hobart OK 71 101 73 101 / 0 0 0 0
Wichita Falls TX 74 103 76 103 / 0 0 0 0
Gage OK 67 97 68 100 / 10 0 0 0
Ponca City OK 69 88 67 88 / 20 10 10 0
Durant OK 76 97 72 95 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...Heat Advisory from 1 PM to 9 PM CDT Tuesday for OKZ036-037-044-
045.
TX...Heat Advisory from 1 PM to 9 PM CDT Tuesday for TXZ083>090.
&&
$$
SHORT TERM...14
LONG TERM....14
AVIATION...25
Area Forecast Discussion
National Weather Service Pocatello ID
212 PM MDT Mon Aug 19 2024
.SHORT TERM...Today and Monday. Looking at current water vapor
satellite imagery, there continues to be a deep upper level low
centered just off the coast of Washington. Drier air is filtering
into our area in southwest flow.
Look for isolated showers and thunderstorms over most of our
forecast area today. Some scattered coverage may be possible
across northern Custer county and along the Wyoming border near
Bear lake. Moderate outflow winds of around 40 mph to up to
around 50 mph are possible with these thunderstorms. Our eastern
areas along the Wyoming border are also under a marginal risk
again for severe thunderstorms, mainly due to strong outflow wind
gusts. Plus, these same eastern areas bordering the Wyoming
border are also under an Excessive Rainfall Outlook this
afternoon/early evening. Small hail and brief moderate to heavy
rain are also expected with any thunderstorms.
Tuesday look for drier conditions with drier air moving into the
area in southwesterly flow aloft. With lingering moisture and
afternoon heating, isolated showers and thunderstorms are possible
mainly along the Wyoming border. However, models, overall, are
trending drier for Tuesday.
Expect temperatures today and Tuesday above normal for this time
of year due, in part, to southwesterly flow. Look for mid to
upper 80s with some lower 90s across our lower elevations.
Wyatt
.LONG TERM...Wednesday through next Monday.
Models show a drying trend Wednesday through early Thursday. Winds
do look breezy, gusts of 20 to 30 mph likely, in southwest flow
aloft Wednesday through Friday ahead of the next system coming
over the weekend. Models continue to show moisture moving back in
the area late Thursday into next weekend. Model clusters are in
good agreement in bringing an upper level low through the area on
Saturday. However, they are slightly off on the depth and strength
of the low. Temperatures Wednesday through Friday will be near
normal to slightly below normal. With good precipitation chances
returning, temperatures look to be 8 to 12 degrees below normal
on Saturday and Sunday. Expect temperatures to increase slightly
on Monday but still be below normal.
Wyatt
&&
.AVIATION...
VFR conditions expected for the majority of the forecast period. The
only forecast challenge will be any showers/storms over the next few
hours. Maintained VCTS at KPIH, KIDA and KDIJ but precip chances
look fairly isolated. Hi-res CAMs show the area void of precip after
20/02-03Z tonight and not expecting precip to return on Tuesday.
Winds overnight will be light but will become breezy tomorrow
afternoon, after 18Z, out of the south to southwest around 10-15
knots.
McKaughan
&&
.FIRE WEATHER...
The area is mostly void of precipitation this afternoon as hi-res
models continue to be less and less aggressive with convection today.
Accordingly, have canceled the Red Flag Warning as any tstm coverage
that transpires over the next few hours would be very isolated, at
best. TUesday and Wednesday look mostly dry. Zone 410 will flirt
with Red Flag conditions tomorrow with borderline winds and RH
expected but given the short duration, have held off on any issuance
for now. RHs look to be a touch higher on Wednesday so this day
should be headline free as well. An upper trough will begin
influencing the region later in the week and especially into the
weekend. Increasing precipitation chances and much cooler
temperatures appear likely.
McKaughan
&&
.AIR QUALITY...
Air Quality is good across the whole area currently except the
Stanley area. The Stanley area is being impacted by a fire due
west of Stanley. The HRRR model is showing air quality degrading
significantly for Custer county, especially northern Custer
county, by Wednesday as southwest flow aloft sets up. A slight
air quality degradation is possible across the rest of our
forecast area, as the HRRR model shows smoke from central
California reaching our area in southwest flow aloft.
Wyatt
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
Area Forecast Discussion
National Weather Service Blacksburg VA
806 PM EDT Mon Aug 19 2024
.SYNOPSIS...
Upslope showers will persist through tonight, as an upper level
trough moves across the region. A few thunderstorms will also
continue across the region this afternoon. High pressure builds
in tomorrow and will continue to remain in control throughout
the upcoming week.
&&
.NEAR TERM /THROUGH TUESDAY/...
As of 745 PM EDT Monday...
Key Messages:
-Coverage of showers and thunderstorms will continue to
diminish this evening
Air mass was gradually becoming more stable. Only showers left
were from upslope forcing over the mountains and radar also
showed a cluster of thunderstorms in central Virginia, northeast
of KLYH. HREF models had the precipitation eroding by 02Z/10PM.
No changes to temperatures or wind at this time.
Previous Discussion
As of 200 PM EDT Monday...
Associated with the 500mb low is currently over western
Virginia, gradually shifting east into Central Virginia by this
afternoon. As a result, have some ongoing rain and a few
isolated embedded thunderstorms over SW VA and western VA. These
will continue to progress southeast and east across Virginia
and also through portions of NC, intensifying by this afternoon
over the Virginia/North Carolina Piedmont.
RAP analysis indicates the best destabilization east of the
mountains with CAPE in excess of 1000 J/kg. Colder air aloft
associated with the upper low and strong surface heating has
resulted in steep lapse rates. This should support storms
capable of small hail and perhaps a few stronger wind gusts as
well. Lack of shear will likely keep any widespread stronger
storms to a minimum as they should remain rather unorganized.
Will lose rain/storms with loss of daytime heating. A few
lingering upslope clouds and rain showers possible over West
Virginia tonight, but clearing out tomorrow as high pressure
begins to work east from the Upper Midwest.
Lows tonight in the 50s and a few upper 40s possible. Highs on
Tuesday will be cool for late August... upper 60s/low 70s for
the mountains and mid upper 70s for the lower elevations.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
As of 210 PM EDT Monday...
Key Message:
1) Dry and cool period this week
A colder than normal air mass will shunt south out of Canada on
Wednesday, placing 4-8C 850mb temperatures over southwestern VA.
Surface temperatures will be anomalously cool as well, thanks to
help from low dewpoints and clear skies in the overnight time
frames. Some of our common cold spots in the mountains will drop
into the low 40s, very nearly hitting the 30s in mid-August.
Elsewhere lows will be in the mid 40s to mid 50s, which is still
quite cool. Folks may want a light jacket for their morning commute.
Diurnal swings will be quite large, which is not uncommon this time
of year, but given how cool overnight temperatures will be, highs
will still be below normals, just in the 70s and barely hitting 80
for the Piedmont. Broad surface high pressure over the area will not
allow any precipitation for this forecast period.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
As of 210 PM EDT Monday...
Key Messages:
1). Extended period of no precipitation continues,
2). Temperatures slowly return to normal range and slightly above
normal by the weekend and beginning of the following work week.
By Friday, the upper level trough that will have remained quasi-
stationary across the eastern conus is expected to finally lift
to the northeast. As this happens, the eastern edge of a large
scale upper level ridge centered over Oklahoma is expected to
nudge eastward ever so slightly into the Mid-Atlantic states.
This will lead to a warming trend across the region with
temperatures initially increasing to near normal values by
Friday and Saturday, but continuing to well above normal by
Sunday and Monday. By Sunday, a mid-level shortwave vorticity
maxima is expected to dig southeastward into the Northeast and
eventually Mid-Atlantic states by Sunday night. This will lead
to a retrograding upper level trough to settle into the eastern
conus to start out the beginning of the work week. This may aid
in cooler air returning to the region once again by the middle
of next week as 500mb heights lower areawide.
Overall, precipitation chances will remain minimal across the region
as the aforementioned upper level ridge noses eastward this weekend.
Rain chances increase on Monday; with the development of the
retrograding trough; however, confidence is not high at this time.
High temperatures Friday will initially climb into the low to mid
80s across the piedmont, and upper 70s to low 80s across the higher
terrain. By Sunday and Monday high temperatures will warm back into
the low 90s across the piedmont, and mid 80s across the higher
terrain.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
As of 800 PM EDT Monday...
Air mass was gradually becoming more stable. Only showers left
were from upslope forcing over the mountains and radar also
showed a cluster of thunderstorms in central Virginia, northeast
of KLYH. HREF models had the precipitation eroding by 02Z/10PM.
Short range models and Bufkit forecast soundings showed low
clouds developing over the mountains with IFR to LIFR ceilings
between 04Z/midnight to 09Z/5AM. Locations outside the upslope
area that clear out this evening may have patchy MVFR fog
overnight. For now have MVFR fog in the KBCB TAF and LIFR at
KLWB and KBLF.
Fog will mix out in the morning with VFR visibility across the
region after 14Z/10AM. MVFR ceilings will remain west of the
Blue Ridge for Tuesday morning, then clouds will become
scattered during the afternoon. Downslope northwest wind will
keep clouds scattered in the foothills. VFR ceilings are
expected in the afternoon in the piedmont, including at KLYH and
KDAN.
Winds will be less than 10 knots overnight then once mixing
begins on Tuesday, gusts up to 20 knots are expected.
.EXTENDED AVIATION OUTLOOK...
High pressure builds in and VFR conditions are expected through
the end of the week. Only exception is patchy morning river
valley fog.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...None.
NC...None.
WV...None.
&&
$$
SYNOPSIS...BMG
NEAR TERM...AMS/BMG
SHORT TERM...VFJ
LONG TERM...EB
AVIATION...AMS/BMG
Area Forecast Discussion
National Weather Service Tampa Bay Ruskin FL
850 PM EDT Mon Aug 19 2024
...New UPDATE, AVIATION...
.UPDATE...
Deep summertime upper trough continues down the Eastern Seaboard
with series of vort maxes dropping SEward from the N Central Gulf
this evening expected to be in the E Gulf and coastal areas Tue
morning. This to combine with deepening SW LL flow over warm,
moist and unstable Gulf waters ahead of the sinking boundary to
the N is expected to produce showers with a few embedded
thunderstorms. Latest grids and forecasts on track.
&&
.AVIATION...
(00Z TAFS)
VFR conditions continue this evening and tonight with light SW
flow. Models continue to show a broken area of SHRA/TSRA forming
in E Gulf around 12Z slowly drifting through the coastal areas
then inland and SW areas around 16Z TUE to keep VCTS in all of
the terminals. Expect conditions to improve mid day with increased
SW flow around Tampa Bay but delayed to nr 00Z other areas.
&&
.DISCUSSION...
Issued at 147 PM EDT Mon Aug 19 2024
Current water vapor imagery and RAP upper air analysis indicate a
deep trough along the Eastern Seaboard extending southward into the
FLorida Peninsula. There is an area of subsidence on the western
side of this trough axis with drier air advecting into the Tennessee
Valley and Southeastern U.S. Additionally, an area of convection can
be noted across the northern Gulf of Mexico. At the surface, a cold
front is beginning to lose southward progress and transitioning into
a stationary boundary. This boundary stretches from N-S along the
Carolina Coast to the southwest along the northern Gulf Of Mexico.
This front will continue to be the focus for showers/storms
throughout the afternoon and evening hours. Further to the south,
there is a weak inverted surface trough that has lead to some
enhanced low-level convergence with an area of showers/storms across
southwest Florida. However, the main focus for the potential for a
few strong to severe storms will be across northern areas where the
upper trough, instability, amd lift will be strong enough to produce
a low threat for severe storms. Highs this afternoon will climb into
the low to mid 90s with peak heat indices ranging form around 103-
108 degrees.
Any storms that form along the front later this afternoon/evening
will slowly drift southward overnight into early Tuesday morning.
However, do expect intensity and coverage will wain during this
timeframe. The latest CAM guidance seems to be in align with this
forecast with showers/storms overnight along the Nature Coast,
drifting southward into the Tampa area early Tuesday morning.
The stationary boundary continues to be the main story throughout
the upcoming week. The upper level pattern remains rather stagnant
throughout Thursday or so. The upper level trough closes off across
New England with a ridge both to the east and west. This stagnant
pattern leads to very little movement in the stationary boundary
with upper flow parallel to this boundary. Moisture will continue
to increase throughout the week with PW values climbing into the 1.8-
2.0 inch range. Due to this, elevated PoPs feature throughout much
of the upcoming forecast period from Tuesday onward during the
afternoon and evening hours. Dry conditions could move into northern
areas of the forecast area at times as the front nudges southward.
Low level flow throughout this timeframe will be from the southwest.
The pattern becomes a bit more progressive to the north late in the
week and into the weekend. The trough shifts further to the
northeast and the ridge over the Atlantic becomes the main players
with easterly flow across the Peninsula. PW values remain elevated
along with the elevated chances for afternoon showers and storms.
&&
.MARINE...
Issued at 147 PM EDT Mon Aug 19 2024
Onshore winds around 10-15 knots and seas 2 feet or less can be
expected through the week with no headlines expected. A frontal
boundary over northern Florida will shift southward through the week
with increasing rain chances expected for the latter part of the
week.
&&
.FIRE WEATHER...
Issued at 147 PM EDT Mon Aug 19 2024
A frontal boundary across northern Florida will shift south through
the week. A chance of showers and storms can be expected each day
with higher chances in the latter part of the week. No fire weather
concerns are expected.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 78 91 78 90 / 40 70 30 60
FMY 80 91 79 92 / 30 50 50 70
GIF 78 93 77 92 / 10 70 30 70
SRQ 80 91 78 91 / 20 60 50 60
BKV 75 92 74 92 / 30 50 20 60
SPG 83 91 83 91 / 40 60 40 60
&&
Sea Breeze Thunderstorm Regime For Tuesday: 5
Sea Breeze Thunderstorm Regime For Wednesday: 8
For additional information on sea breeze regimes, go to:
https://www.weather.gov/tbw/ThunderstormClimatology
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...None.
Gulf waters...None.
&&
$$
UPDATE/AVIATION/MARINE/FIRE WEATHER...RDavis
DECISION SUPPORT...Delerme
UPPER AIR/CLIMATE...Delerme