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218
FXUS61 KBGM 200156
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
956 PM EDT Mon Aug 19 2024

.SYNOPSIS...
Spotty showers and sprinkles will linger tonight, especially
across central NY. Cool and becoming breezy Tuesday and
Wednesday with additional scattered lake effect showers.
Quieter and warmer conditions are expected for the second half
of the week.

&&

.NEAR TERM /THROUGH TUESDAY NIGHT/...
-- Changed Discussion --
945 PM Update...

Just some minor adjustments made at this time. Increased PoPs
around and downwind of the Finger Lakes with some lake effect
rain showers streaming off of them which will likely continue
into the overnight. The rest of the forecast remains on track.

640 PM Update...

Some minor adjustments through this evening, but allowed for
spotty showers or sprinkles to linger much of the night across
the Finger Lakes region and higher terrain of CNY. Increased
cloud cover and the chances for lake effect showers and
sprinkles tomorrow farther south across the Twin Tiers and NE
PA and increased PoP values over CNY. Instability looks to be
lacking tomorrow, so the chance for thunder was removed in areas
east of I-81. Sustained winds and gusts were also increased for
both tomorrow and Wednesday afternoon. One thing to monitor
Wednesday with low heights aloft and more instability present
is the potential for some small hail in any robust shower or
isolated thunderstorm in the afternoon.

130 PM Update...

A slow-moving weak cold front moving across Central NY and NE PA
will continue to bring showers and a weak storm or two, mainly
east of I-81. Behind the front, north-northwesterly flow will
help to produce some very light lake-effect rain showers across
Central NY that will last through the rest of the day, and taper
off soon after sunset. The center low of a trough will push
southward into the area, allowing for these lake- effect light
rain showers to likely start up again tomorrow afternoon and
last into Tuesday night. This will pull down colder Canadian air
into the air, dropping Tuesday high temperatures to the low to
mid 60s, and some higher terrain areas even in the high 50s.
Additionally, we`ll see tonight`s and Tuesday`s overnight
temperatures fall into the high 40s to low 50s.
-- End Changed Discussion --

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
235 PM Update...

No significant changes to this portion of the forecast with the
latest afternoon model guidance. Wednesday still looks
unseasonably cool and unsettled under the influence of a cutoff
upper level low. 1000-500mb thicknesses drop down to 546dm, and
850mb temperatures drop to around +4C. With Lake Ontario water
temperatures around +22C, that will provide quite a bit of lake
induced instability. Wrap around moisture on the western side of
the upper level low will combine with the lake moisture to bring
scattered to numerous lake enhanced rain showers to the
region...there could also be some isolated thunderstorms due to
the steep low level lapse rates, cold pool aloft and MLCAPE
approaching 500 J/Kg in the afternoon. Much below average
temperatures continue, with highs in the 60s...to perhaps lower
70s in the Wyoming Valley

The upper level low is slow to move out, but with the loss of
daytime heating/instability it should be mainly dry Wednesday
night. Cool, with perhaps some patchy fog...lows in the mid-40s
to lower 50s.

The upper level low lingers over New England and northern NY
into Thursday now. This will bring some scattered clouds and
perhaps isolated rain showers back into portions of Central NY.
It will finally warm up closer (but still below) to average,
with afternoon highs in the upper 60s to mid-70s expected.

Thursday night is quiet, with surface high pressure building
into the region. Valley fog is likely to form. This will bring
mainly clear skies and cool overnight lows in the mid-40s to
lower 50s.

Previous Discussion Below

An anomalously deep and compact upper low will pivot across the
Northeast during midweek with much cooler-than-normal
temperatures as well as scattered showers, especially in Central
New York where lake enhancement will occur. You read that
correctly, a lake effect influence in August, which is quite
doable considering 850mb temperatures projected in the models as
low as 3-4 degrees Celsius versus water temperatures closer to
20 degrees Celsius. Ensemble data shows the return interval of
these chilly 850mb temperatures for this date, to be less than
one day per 10 years. While forecast temperatures are not at
record lows, since there will be cloud cover and mixing, they
will be within a few to several degrees of record low maximums
for Binghamton-Syracuse, and more like 8-9 degrees from record
low maximum for Scranton. To summarize, daytime temperatures
10-14 degrees below average will definitely feel like an
abruptly early taste of Fall.

Models project the upper low core dropping directly over the
area Wednesday, with temperatures starting off at morning lows
of only mid 40s to lower 50s. Cyclonic chilly flow around it
appears likely to bring a deeper lobe of moisture, helped by
lake enhancement as well, to yield plenty of clouds. Chances for
showers had to be adjusted significantly up into the high
chance to likely range, particularly for Central New York
Wednesday. Amounts will not be much, only a tenth to quarter of
an inch at most with majority less than a tenth of an inch. But
at least scattered showers will certainly be around for Central
NY into the Twin Tiers, and a few stretching even deeper into
Pennsylvania. Highs will be only in the 60s for most locations.

Wednesday night, instead of northwesterly flow with gusts of
10-20 mph like during the daytime, there will be backing of
lighter winds to westerly or even west-southwesterly. This will
diminish the lake influence to mainly along and north of the NY
Thruway, ending showers for most of the area as the upper low
also starts to head northeast of the area. While we will still
be within its outer periphery Thursday, after lows again of mid
40s-lower 50s, temperatures will moderate somewhat to highs of
upper 60s mid 70s. While Wednesday will have plenty of clouds,
more sunshine will be managed on Thursday.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
300 PM Update

Quiet weather under upper level ridging is expected for most of
this period. It is likely to be dry this entire longer term
period under a zonal to west-northwest flow. The heat dome over
the midwest does gradually build eastward into our area.
Thicknesses and upper level temperatures rise heading into the
weekend and early next week. This will allow surface
temperatures to see a warming trend. Look for highs in the
mid-70s to lower 80s Friday and Saturday, with comfortable lows
in the 50s. Sunday and Monday feature highs back well into the
80s with dew points and humidity starting to rise a bit.
Overnight lows rise back up into the upper 50s and 60s.

&&

.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
Cool and moist northwest flow will dominate this terminal
period. All BGM terminals had mainly MVFR ceilings at this time
with pockets of IFR floating around in light showers at KBGM,
and KITH. We expect ceilings to remain MVFR for most of the
night with fuel alternates at times at KBGM and KITH. The
conditions will gradually improve to VFR in stratocumulus for
Tuesday from late morning into the afternoon. There will be
light lake effect rain showers and sprinkles around as well
Tuesday afternoon. Coverage is not enough at this time to
warrant mention in terminals.

Winds will be northwest around 7 to 11 knots gusting between 15
and 20 knots through the period.

.Outlook...
Tuesday night through Wednesday...Mainly VFR; lingering showers
possible, especially over the Central NY terminals.

Thursday through Saturday...Mainly VFR with high pressure over
the region.

&&

.BGM WATCHES/WARNINGS/ADVISORIES...
PA...None.
NY...None.

&&

$$

SYNOPSIS...DK
NEAR TERM...DK/KL
SHORT TERM...MJM/MDP
LONG TERM...MJM/MDP
AVIATION...DJN