-- Discussion containing changed information from previous version are highlighted. --
954
FXUS61 KBGM 200705
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
305 AM EDT Mon May 20 2024

.SYNOPSIS...
After mostly clear skies and valley fog tonight, mostly sunny
skies and warmer temperatures are expected on Monday. Very warm
temperatures are expected Tuesday into Wednesday. There will be
a chance for scattered thunderstorms later Wednesday into
Thursday as a cold front approaches the region.

&&

.NEAR TERM /THROUGH TUESDAY/...
630 PM Update:

Main change with this update was to remove the slight chance
PoPs for the Catskills-Poconos since it is unlikely that any
showers will form. Even if something does pop up, any
precipitation will likely not be measurable. Otherwise, the
forecast remains on track. Setup looks good for radiational
valley fog to form overnight.

3 PM Update

Tonight, high pressure remains in place and with radiational
cooling and with plenty of low level moisture (low dew point
depressions), valley fog will likely develop over the region.
There is some question as to how extensive the fog will be, and
if if can reach some of the mid elevation locations as well. It
will be seasonable overnight, with lows in the 50s.

Monday is looking even warmer as 500 mb heights continue to
rise towards 580 dm and 1000-500mb thicknesses reach 567dm.
With ridging in place, a stout subsidence inversion around 700
mb will likely keep most of the region capped despite some
surface based CAPE able to develop with the heat and humidity.
Once again there is a small chance that terrain and or some lake
breezes will help a couple showers or thunderstorms break
through the cap, over the Central Southern Tier and SW Finger
Lakes but odds are low (20%). The rest of the region will see
the fog burn off by mid morning, then mostly sunny skies. The
latest trends in the bias corrected guidance is increasing
temperatures even more...with highs in the mid to upper 80s for
the valley locations...with upper 70s to low 80s over the higher
elevations. Winds will be light west-southwesterly under 10
mph.

High pressure and clear skies continue into Monday night, with
perhaps some patchy valley fog again. It will be milder, with
lows only dipping down into the upper 50s to lower 60s.

&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...

-- Changed Discussion --
High pressure will move off the east coast Tuesday night. This will
result in a continued warming trend through Wednesday with
southwesterly winds. Most locations should rise well into the 80`s
with a few locations close to 90 on Wednesday as the NBM has caught
on to the overall pattern. With dewpoints only around 60, heat index
values should not be much higher. Lows generally in the 60`s at both
Tuesday night and Wednesday night. Highs Thursday trend several
degrees cooler with the frontal passage.

A frontal boundary still looks to move in later Wednesday and
Thursday to break down the ridge. Enough lift and moisture looks
present for at least some scattered showers with the frontal
passage. Instability during the afternoons surface CAPE is currently
modeled to be around 1,000 J/KG each afternoon and evening so some
thunderstorms will be possible as well. Still some timing
differences with the operational models and ensemble guidance with
the frontal timing. The instability part has been fairly
consistent on the operational models and respective ensembles
if we can get some convection in the afternoon and evening
Wednesday and or Thursday. A first look at model soundings shows
steep low level lapse rates with some mid-level dry air as well
later Wednesday. With a fair amount of shear as well, the
potential is present for some strong storms with gusty winds and
hail.
-- End Changed Discussion --


&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...

-- Changed Discussion --
Seeing some signal in the ensemble guidance along with the latest
00Z 5/20 ECMWF that the front may check up not to far south of the
area Thursday night through the weekend. So while the upcoming
weekend looks mainly dry, isolated showers or thunderstorms can not
be ruled out across NE PA closer to the front. Temperatures trend
cooler with lows in the 50`s and in the 70`s generally.
-- End Changed Discussion --

&&

.AVIATION /07Z MONDAY THROUGH FRIDAY/...
Clear skies have lead to some fog development already that will
expand through the remaining of the night. Dry air at BGM and
AVP has lowered confidence in the severity of the fog so the
lowest restrictions were put into a tempo rather than
predominant. ELM has already seen some fog but once the high
clouds moving overhead clear the fog will return. Relative
humidities at ITH and SYR are already near 100% so decided to
add some IFR restrictions as fog development is looking more
likely.

Fog clears out by 13Z this morning with VFR conditions expected
at all terminals thereafter.

Outlook...

Monday night through Friday...Mainly VFR. Some showers possible
late Wednesday through Thursday.

&&

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

&&

$$

SYNOPSIS...BJG/MJM
NEAR TERM...BJG/MJM
SHORT TERM...MWG
LONG TERM...MWG
AVIATION...AJG/MPK