443
FXUS61 KBGM 171047
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
647 AM EDT Sat May 17 2025

.SYNOPSIS...
Multiple rounds of showers and thunderstorms are expected today with
isolated stronger thunderstorms possible this afternoon. A system
will bring cooler conditions and another round of showers on Sunday.
Next week starts out cool and dry before the next system moves into
the region around midweek.

&&

.NEAR TERM /THROUGH SUNDAY/...
625 AM Update...

The latest CAMs guidance are in and very few are supporting
shower and thunderstorm activity this morning. The storms
currently over Lake Ontario may extend southward and clip N.
Oneida. Otherwise, it is looking more and more to be a quiet
morning. Skies are still expected to clear later this morning
allowing for daytime heating and instability increasing. Some
model guidance are picking up on this while a few others
continue to show lesser amounts of instability. Based on all of
this, confidence has increased since the previous update in the
severe potential for this afternoon. The best timing looks to
be noon to 6pm with one more line of showers to move through
during the late afternoon and evening hours

For this update, PoPs were decreased for the next few hours.
Temperatures were also touched up based on the latest
observations.

335 AM Update...

For now, all is quiet but a couple of waves will pass through this
morning and support isolated showers and thunderstorms. The
environment will be partly capped until the mid to late morning
hours. Even with around 500 J/kg and 35-40kts of 0-6km bulk shear,
stronger storms are not expected until the cap erodes. There is some
uncertainty on how much coverage there will be with the initial round
of showers and thunderstorms. The NAMNest has a band extending across
the entire region while most other CAMs keep most of the activity
across north-central NY. NBM and HREF guidance was a reasonable
blend for the morning hours.

Heading into the afternoon, models are not showing much of a
resurgence of instability despite skies clearing some today and
temperatures climbing into the 70s and 80s. This could partly be due
to the initial batch of showers/storms using most of the energy
early on and leaving little for a cold front that brings the main
round of showers/storms this afternoon. Given this, it makes sense
that SPC has moved the slight risk east and left most of the region
in a marginal risk. Evaluating forecast soundings and indices, the
main concerns will be gusty winds and small to large hail. DCAPE
values are not expected to be high, but frontal boundaries can
generate some stronger gusts. There is also a concern for localized
flash flooding. While PWATs are not significant, any convective
shower could drop a high amount of rainfall in a short period of
time, as what was observed last night. Grounds remain saturated and
some of the harder hit areas yesterday will be most vulnerable. With
models favoring activity across north-central NY, that will be
another area to watch. WPC maintains a marginal risk for excessive
rainfall over the Mohawk Valley and Tug Hill regions. This front
will move through quickly and should be east of the region by the
late evening hours. The CAMs are in relatively good agreement for
the afternoon with some difference in coverage. Again, a blend of
the NBM and HREF was used for PoPs though some manual adjustments
were also made.

Overnight, areas south of the Souther Tier will remain dry while the
rest of the region will have a chance for rain showers as a low
pressure system swings through the region. Cooler air begins to
filter in behind the departing front leading to lows in the 40s and
low 50s. For Sunday, rain showers will continue to spread south
across the region. Temperatures will struggle to rebound as highs
will only be in the 50s and 60s. On top of that, a sharpening
pressure gradient will lead to winds increasing. Peak gusts will be
in excess of 25 mph. Certainly not the conditions expected as we
approach the summer season in just a couple of weeks.

&&

.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY NIGHT/...
315 AM Update

This period will feature mostly dry, but cooler than average weather
across the region. There will be a slowly departing upper level low
for Sunday night, some lingering slight chances for rain showers in
the evening give way to partial clearing overnight. Northwest winds
remain steady between 5 to 15 mph overnight, so this should help
eliminate the potential for any fog or frost formation. Cool
overnight lows in 40s expected areawide; except some localized upper
30s in the coldest high elevation valleys of the Catskills and
northern Oneida county.

Monday features a cool north-northwest flow pattern over the area,
with subtle upper level height rises and weak surface ridging
present. This will lead to mostly sunny skies, and allow the area to
finally dry out some. With 850mb temperatures hovering near 0C,
daytime highs will be cooler than average, only in the 50s to lower
60s...except 65-70 for the Wyoming Valley. This is about 5 to 8
degrees below average for mid May. Northwest winds will also be
quite breezy, sustained between 10-18 mph with gusts up to around 25
mph at times.

Monday night will be chilly under mostly clear skies and weak
surface high pressure. Winds try to decouple in the sheltered
valleys, but remain northwest 5 to 10 mph elsewhere. Did add in a
mention of frost into the weather grids; again mostly for the
colder, sheltered valleys of Steuben county...the Catskills,
Susquehanna region of NY and northern Oneida county. The growing
season has begun for our entire forecast area as of May 11th; so if
confidence grows in frost formation, advisories will be issued where
needed. Forecast lows range the mid-30s to around 40.

Central NY and Northeast PA will be between weather systems on
Tuesday, with a cool and dry northerly flow continuing. Expect
partly to mostly sunny skies, lighter winds and seasonably cool
highs between about 55 to 65 over the forecast area. Tuesday night
will have increasing clouds with a chance for rain developing late
at night as the next low pressure system approaches from the Ohio
Valley; not quite as cool as Monday night, with lows in the 40s for
most locations expected.

&&

.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
315 AM Update

Unsettled, cool and wet weather is expected through this long term
period as a series of slow moving, nearly cut off upper level lows
meander around the forecast area.

On Wednesday the 500/700mb low will be centered over lower Michigan
as it develops and strengths through the day. Surface cyclogenesis
will take place, with a primary surface low tracking across western
NY and a new, secondary low developing over the DELMARVA. This will
bring periods of rain to the entire forecast area, spreading slowly
south to north through the day, along with overcast and very cool
conditions. Temperatures are likely to be stuck in the 50s to perhaps
around 60 all day with the thick cloud cover, cold temperatures
aloft and periods of rain. Surface winds will be southeasterly
at 8-15 mph. Rainfall amounts are forecast to be upwards of a
half to three-quarters of an inch. By Wednesday night and
Thursday the large, expansive upper level low remains stalled
over the area with additional periods of rain expected (70-85%
PoP). Thursday looks to be even cooler, as 850mb temperatures
bottom out around +1C. Temperatures are likely to remain nearly
steady in the mid-40s to mid-50s overnight and through the
daytime hours.

The main upper level low passes directly overhead on Friday, as it
continues to very slowly spin east. This will mean more clouds and
numerous rain showers for Central NY and Northeast PA, with
temperatures perhaps nudging up a few degrees into the mid-50s to
low 60s...overall it still looks mainly cloudy and unsettled.
Rainfall amounts are not looking very high, with generally less than
a half inch expected each day (after Wednesday). By Saturday, the
upper level low looks likely to stall over northern New England and
southern Quebec. More upper level energy and shortwave disturbances
still rotate south into our area through the day. Scattered to
numerous showers are still in the forecast, with mainly cloudy skies
and continued cool temperatures in the upper 50s to mid-60s expected.
There could be some modest instability by Saturday, but for now
left out any mention of thunder in the forecast. Rounding out
next weekend, from this early vantage point it looks like there
could be more dry time on Sunday (but still shower chances) and
a gradual warming trend with highs back in the 60s to around 70
possible. Overall it is looking unsettled and cooler than
average for most of the upcoming Memorial Day Weekend.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
Conditions will be mainly VFR through the evening hours. Models
have backed off on morning showers and thunderstorms and are
now favoring a round of scattered showers and isolated
thunderstorms this afternoon and early evening. Then another
line of showers will move through during the late afternoon to
late evening timeframe. Prob30 groups were added to RME and SYR
for thunderstorm chances this afternoon as most model guidance
are showing multiple showers/storms passing through those
terminals while coverage is a bit more sparse around the rest of
the terminals. Tempo groups were maintained for when the later line
of showers moves through. Visibility restrictions are possible
for any showers or storms that pass over terminals.

VFR conditions are then expected after 00z and through around
06z Sunday. Then ceilings begin to fall as a low pressure system
swings into the region from the north. Ceilings will drop into
MVFR and Fuel Alt categories at all CNY terminals prior to 12z.
Rain showers will also be possible at RME and SYR. AVP is
expected remain at VFR.

Light and variable winds will pick up later this morning. Winds
will vary between southwest and west through the day with
sustained speeds of 8 to 12 kts and peak gusts around 20 kts.
Winds will be stronger within rain showers and thunderstorms. Then
tonight, gusts subside and winds settle out of the west-
southwest.

Outlook...

Sunday...Scattered rain showers possible, especially at the
Central NY terminals, which may result in occasional
restrictions.

Sunday night through Tuesday...Mainly VFR expected.

Wednesday...Restrictions likely with rain showers.

&&

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

&&

$$

SYNOPSIS...BTL/MDP
NEAR TERM...BTL
SHORT TERM...MJM
LONG TERM...MJM
AVIATION...BTL