-- Discussion containing changed information from previous version are highlighted. --
889
FXUS61 KBGM 031027
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
627 AM EDT Mon Jun 3 2024

.SYNOPSIS...
Temperatures will be warmer to start the week and isolated afternoon
thunderstorms will be possible through Tuesday. Chances for more
widespread showers and scattered storms increase in the latter half
of the week as a slow moving system passes through the region.
Temperatures will trend cooler beginning midweek.

&&

.NEAR TERM /THROUGH TUESDAY/...
-- Changed Discussion --
615 AM Update...

Some lingering showers remain this morning with the support of a
passing shortwave. These showers are on their way out though and
should exit the region within the next hour. Fog did develop in
more locations, especially some valleys, but we are starting to
see the fog lift into the higher elevations. Similarly to the
rain showers, fog is not expected to last too long this morning.
Temperatures and dew points needed some minor updates during
this update, mainly over the next few hours to match closer to
the trend of current observations. Otherwise, the forecast was
doing well.

325 AM Update...

A few showers remain early this morning. Fog is beginning to develop
this morning despite overcast skies overhead. While expected, it is
taking a little long than originally forecasted. Fog will lift out
shortly after sunrise. Quiet conditions are then expected through
the rest of the morning hours. A weak short wave will move in from
the northwest and kick off some isolated thunderstorms. The thought
continues to be that the best chances will be in the Poconos and
Catskills where orographic lift can aid in breaking through a cap.
This is what the CAMs seem to pick up on as well. Some of the global
models also favored far western portions of the Twin Tiers and NEPA
to have some showers/storms, so slight chance PoPs were added to
these regions as well. There is some uncertainty on how unstable the
environment will be. The NAM is significantly higher with CAPE
values than most other guidance. All guidance agree that shear will
be weak though, so any thunderstorms that can develop will likely be
short lived and should be fairly weak. Otherwise, most of the region
will likely stay dry today. With an upper ridge building into the
region, temperatures will be slightly warmer than yesterday. Highs
will be in the upper 70s to low 80s.

The overnight hours will be dry with high pressure in place. Model
soundings are showing a sharp inversion near the surface. With
mostly to partly clear skies and light winds also expected, river
valley fog will be possible. Temperatures will be mild, only falling
into the mid 50s to low 60s.

Weak waves within the ridge will support another round of isolated
showers and thunderstorms Tuesday. These waves will be weaker than
the one moving through today. MLCAPE is modeled to be around 500
J/kg and will paired with 15 to 20 kts of shear. Based on these
values, strong storms are not favored and any storms that do develop
will be short lived. The Northern Tier of PA and CNY will have the
best chance at any showers/storms. Otherwise, Tuesday will be dry
with partly sunny skies. Temperatures will be in the 80s across the
region.
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&&

.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
350 AM Update

The weather pattern will be turning much more active and eventually
cooler in this timeframe, as a slow moving, nearly cut-off upper
level low approaches. It starts off quiet and warm Tuesday night,
with just an outside chance for a stray shower or storm...muggy
with lows in the upper 50s to mid-60s over the region.

The area will be under a transitioning weather pattern on Wednesday,
as there appears still be some modest upper level ridging over the
area. However,building moisture and instability along with an
incoming shortwave trough out ahead of the parent upper level low
could spark off scattered showers and t`storms. Still warm and humid
(sfc dew points 60-65) with highs in the upper 70s to low 80s, except
mid-80s for Syracuse metro and Mohawk Valley region.

The first frontal boundary is progged to swing through the area
Wednesday night into Thursday. The exact timing remains somewhat
uncertain...but guidance is honing in on this period for a round of
steady rain and embedded thunderstorms, as MLCAPE of 300-600 J/Kg
will be possible. PWATs rise to around 1.50 to 1.75 inches, and warm
cloud layer reaches 10-11k ft; especially Wednesday night through
mid-morning Thursday. Again, there are minor timing differences
between the GFS, which hangs onto the deep moisture and instability
longer into the day on Thursday...and the ECMWF, which drops PWATs,
moisture and instability quickly from west to east Thursday morning.
Used blended (NBM) ensemble guidance for the official forecast to
account for these timing discrepancies in the deterministic
guidance. WPC does have out area highlighted in a Marginal Risk
for excessive rainfall (at least 5% risk of flash flooding)
during this Wednesday through Thursday morning time range...and
this will be something to monitor closely moving forward. With
some partial clearing expected at times on Thursday, daytime
highs still reach the mid-70s to lower 80s, with dew points
gradually falling in the afternoon, making it feel less humid.

The upper level low spins east, to a position near Toronto Thursday
night. With the loss of daytime heating and instability we are
expecting just a few rain showers around overnight, with more
comfortable lows in the 50s to near 60.

&&

.LONG TERM /FRIDAY THROUGH SUNDAY/...
350 AM Update

This period will be dominated by a slow moving, redeveloping upper
level low/trough over the region. The low spins over western NY and
southern Ontario on Friday, putting our area under a broad cyclonic
southwesterly flow. Daytime heating and instability will allow
scattered to numerous showers to develop in the afternoon...with
isolated thunderstorms also possible. Not as warm, with highs in the
70s. Skies will be mostly sunny in the morning, but quickly becoming
partly sunny to mostly cloudy in the afternoon, under the influence
of the upper level low. Shower chances lower Friday night, with the
loss of instability. Seasonable with lows in the low to mid-50s.

By Saturday, there is good model agreement that the upper level low
will be right over us, or very close by. 1000-500mb thicknesses fall
into the low 550dm range, and 850mb temperatures are around +8C.
This will allow for more scattered to numerous showers and isolated
thunderstorms to develop during the day. Below average temperatures,
with highs only in the upper 60s to lower 70s...except around 75 in
the Chemung and Wyoming Valleys. Much of the same for Sunday and
Monday, as our area remains under a broad upper level trough
pattern. This will lead to drier and partly cloudy conditions at
night...with  scattered to numerous showers developing for the
daytime hours and a slight chance for thunderstorms. Temperatures
are steady with highs in the upper 60s to mid-70s and lows 50 to 55.

&&

.AVIATION /10Z MONDAY THROUGH FRIDAY/...
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MVFR ceilings may linger at ITH for the first couple of hours in
the TAF period. Otherwise, all terminals are expected to be VFR
until around 06z Tuesday. Overcast skies will scatter out later
by midday. Conditions will be better for fog development. BGM,
ELM, ITH, and RME will have the best chance for fog and
restrictions. Exact timing of fog and lowest restrictions are
uncertain and will require additional refining with future
updates.


Outlook...

Tuesday...Mainly VFR. Isolated showers/storms during the
afternoon and evening hours.

Wednesday...Low chance of showers/storms and associated
restrictions.

Wednesday night through Friday...Increasing chance of
showers/storms and associated restrictions.
-- End Changed Discussion --

&&

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

&&

$$

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