000
FXUS61 KBGM 271005
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
605 AM EDT Tue Jul 27 2021

.SYNOPSIS...
A cold front will cross Lake Ontario this afternoon and push
thunderstorms across NY and PA through the early evening hours.
A few storms may include gusty winds. Wednesday will be
quieter, with a chance for an isolated shower. Another round of
storms will move through the region on Thursday.

&&

.NEAR TERM /THROUGH WEDNESDAY/...
A cold front will cross Lake Ontario this afternoon and evening.
Instability will build ahead of the front, with CAPE values in
the 1000-1500 j/kg range from the Finger Lakes into the Northern
Tier of PA. With shear developing and a supportive short wave
forecast to move through the flow, it`s likely an area of strong
to severe convection will reach the northwestern forecast area
by mid-afternoon, then spread southeastward through the early
evening hours.

A slight risk for severe thunderstorms exists for much of
Central NY, with a marginal risk over NEPA.

Once the storms pass tonight, low clouds and scattered showers
will continue into Wednesday morning.

With an upper level trough in place, we can`t rule out isolated
shower activity on Wednesday. A thunderstorm could also pop up
over NEPA, where the models are forecasting a narrow area of
instability.

&&

.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
Clouds increase ahead Wednesday night of weak frontal boundary
will push through the region Thursday. This front should provide
just enough lift and moisture for a few showers and perhaps a
thunderstorm or two. However, deeper moisture and instability
will be confined to areas south of the cold front portion of the
boundary across the southern Great Lakes. This will keep
coverage and intensity of the precipitation down and limit the
potential for any strong to severe thunderstorms.

Still low level lapse rates should steepen
enough to where a gusty storm or two can not be ruled out.
Fairly fast storm motions and lower PW values compared to
recent heavier rainfall events in the past month too. Highs
should make it to around 80 after starting around 60 depending
on clouds and precipitation Thursday afternoon.


Our first potential lake effect shower chance of the season
Thursday night into Friday with northwest flow and warm lake
water. At the very least, clouds will likely be much more
stubborn to hang on than model guidance indicates into a good
chunk of Friday. Temperatures in the 60`s and 70`s due to plenty
of cloud cover.

&&

.LONG TERM /FRIDAY NIGHT THROUGH MONDAY/...
High pressure then builds into the region Friday night through
Saturday night. Clear skies and light winds may very well lead
to favorable radiational cooling Saturday night with a few
indications of upper 40`s in a few spots. With full sunshine
temperatures should get into the 70`s making for a great weather
start to the weekend. A bit warmer Saturday night compared to
Friday night due to southwesterly flow ahead of the next frontal
boundary.

Another weak frontal boundary looks to pass through on Sunday.
Deep moisture and instability are modeled to be lacking once
again with the front only providing enough lift for scattered
showers and perhaps a thunderstorm with light QPF. This front
moves southeast of the region by Monday though as usual some
timing uncertainty is present within the ensembles. Highs in
the 70`s with lows in the 50`s.

&&

.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
Dense river valley fog at KELM will cause visibility
restrictions of 1/2 SM or less through 1200z, then gradually
recede between 1230z and 1300z.

VFR conditions are forecast through early afternoon before a
line of thunderstorms moves across our NY terminals between 18z
and 23z. Some of these storms will contain gusty winds. MVFR
restrictions will be likely in storms.

After the storms move through, clouds will lower to between 1500
and 3000 feet across our NY terminals Tuesday night, with IFR
ceilings likely at KBGM. Minor visibility restrictions are
expected.

Outlook...


Wednesday through Wednesday night...Mainly VFR.

Thursday through Friday...Scattered showers/thunderstorms and
associated restrictions possible, especially the afternoons.

Friday night through Saturday...Mainly VFR.

&&

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

&&

$$
SYNOPSIS...DJP
NEAR TERM...DJP
SHORT TERM...MWG
LONG TERM...MWG
AVIATION...DJP

NWS BGM Office Area Forecast Discussion