294
FXUS61 KBGM 240149
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
949 PM EDT Wed Apr 23 2025

.SYNOPSIS...
Clear to partly cloudy late tonight with a few showers possible
through tomorrow morning, mainly over the northern Finger
Lakes. Isolated showers and thunderstorms can pop up tomorrow
afternoon and evening, especially across central NY. The next
system will arrive Friday and Saturday, bringing showers and a
slight chance of isolated thunderstorms.

&&

.NEAR TERM /THROUGH THURSDAY NIGHT/...
935 PM Update...

Little change has been to the forecast overall through tomorrow
night. Temperatures have been a little slow to drop off early
this evening so blended in the latest obs and a bit of the HRRR
to the next few hours. A round of spotty showers is still
expected later tonight through tomorrow morning, generally
through about 14Z, for CNY, especially around the Finger Lakes
region. Taking a look at the latest forecast soundings, the
chance for showers and thunderstorms remains isolated tomorrow
afternoon and evening from south of the I-90 corridor to the
Twin Tiers beginning around 19-20Z, but any thunderstorm that
does manage to pop up could produce locally gusty winds and even
some small hail.


313 PM update...
Main concerns/challenges in the near term are focused on the
potential for rain showers late tonight across the northern lake
plain of the Finger Lakes and then some redevelopment of
scattered light showers and even a few weak thunderstorms from
Steuben County, along the southern Finger Lakes into the
northern Catskills Thursday afternoon. Severe weather is not
expected. Temperatures will be some of the warmest so far this
season.

A low amplitude upper level ridge axis at 500mb is moving east
across the Northeast US this afternoon and working in
conjunction with a narrow ribbon of dry air and a weak surface
ridge to produce dry weather conditions and mostly sunny skies
today. A more robust plume of moisture is currently situated
farther to the west over the central Great Lakes and will
combine with a passing weak upper s/w that will move across the
western Great Lakes and northern NY later tonight.

The air mass this afternoon is currently being modified by weak
warm air advection from the southwest and this pattern will
slowly continue tonight and even more so Thursday during the
day. Temperatures have climbed into the 60s for most of the
forecast area with highs expected to top out in the lower 70s in
the Chemung Valley and Wyoming Valley in the next couple hours.

Clear skies tonight will lead to some radiational cooling
tonight and drop lows into the upper 30s to mid 40s. Cannot
completely rule out patchy fog...with model forecast soundings
indicating a very sharp and well-defined low level
inversion...but confidence is not high enough to include in the
official forecast at this time given the relatively lack of
near-surface available moisture.

As mentioned above, a weak short wave is forecast to move
quickly from western NY into northern NY late tonight and
potentially trigger a few light rain showers during this time.
The forcing along this wave is quite weak and deep moisture is
on the lower side as well. Any precipitation with this wave will
be only a couple hundredths of an inch.

Temperatures are expected to rise quickly into the upper 60s
and lower 70s before noon Thu and then into the mid to upper
70s, close to 80 by the mid afternoon time frame. With dew
points in the upper 40s close to 50, boundary layer conditions
will be on the dry end of the spectrum...which could limit the
potential for rain to make it to the ground. A weak surface
boundary and slightly stronger warm air advection in the mid
levels from the SW could help develop a few isolated showers and
weak thunderstorms along the southern tier of NY, into the
Finger Lakes and northern Catskills. ML CAPE values are only
expected to rise into the 200-300 J/kg range with a minimal
amount of shear. Soundings are highlighting the large amounts of
dry air in the mixed layer with an inverted v signature...and
also rather dry air aloft too, so the main threat if any
convection does get going will be for gusty downburst winds.

The boundary layer stabilizes Thursday evening as large scale
suppression dominates ahead of the next low pressure system
expected to move in later on Friday.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
245 PM Update...

An area of low pressure moves through Southern Canada with a
warm front lifting north through NY. Timing of the front is
still a little uncertain but there is more ensemble members that
have the warm front lifting through in the early to mid
morning. With the timing ahead of much solar heating, the region
should be mostly dry outside of the Finger Lakes region into
northern CNY where some instability may develop.

Saturday night has a better chance for widespread precipitation
as a 50 mb shortwave moves in with better accent. Warm and
humid air advecting in at 850 will provide enough moisture for
elevated instability so thunder has been added to the weather
grids for overnight. The instability is not great, largely less
than 300 in most forecast soundings, but deep enough to get some
cloud ice and charge separation.

A strong cold front moves through Saturday with most of the
precipitation ending by mid to late morning. 850 mb temperatures
fall through the day, likely below 0C by the late afternoon. A
tight pressure gradient and boundary layer winds will be strong
enough overnight to keep overnight lows a little warmer, likely
above freezing area wide.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
245 PM Update...

Long term starts off chilly with the cold air mass aloft though
already on Sunday, temperatures aloft begin to recover and with
sun for much of the day, temperatures quickly moderate. Sunday
night looks like it may be colder than Saturday night as there
is a surface high building in with clear skies aloft.
Temperatures were lowered to the NBM 10th for now and may need
to be lowered farther if dew points can mix low during the day
Sunday. Ridging builds back in early next week with temperatures
rising back above seasonal averages by Tuesday. Tuesday into
Wednesday has some potential for severe thunderstorms as
Ensembles all have a strong low passing through Southern Canada
with the region in the warm sector and mean shear approaching 40
knots. Mid level lapse rates have trended steeper in global
models (now >6C/km) and ensembles have trended upwards with mean
CAPE (>400 J/kg).

&&

.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR conditions are expected to continue through the TAF period.
Some clouds will stream in late tonight with isolated showers
through tomorrow morning for the NY Terminals, mainly around
ITH, SYR and RME, but no restrictions are expected. A few pop up
showers and perhaps a thunderstorm or two are possible tomorrow
afternoon and evening, mainly after 19-20Z, but confidence was
too low to include at any TAF site at this time. If any
thunderstorm does develop, any restrictions would be brief.

Winds will be becoming light and variable tonight, shift more
southerly tomorrow and eventually west-northwesterly late in the
period.

Outlook...

Thursday night...Mainly VFR.

Friday through Saturday... Showers with possible restrictions.

Saturday night through Monday...Mostly quiet and dry with high
pressure overhead.

&&

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

&&

$$

SYNOPSIS...BJT/DK
NEAR TERM...BJT/DK
SHORT TERM...AJG
LONG TERM...AJG
AVIATION...BJT/DK

NWS BGM Office Area Forecast Discussion