771
FXUS61 KBGM 300726
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
326 AM EDT Thu May 30 2024

.SYNOPSIS...
Rain showers across the Catskills and Northeastern Pennsylvania
will slowly move east through the overnight hours. Through
Thursday, drier and cooler air will push in from the west with
quiet weather. Temperatures will warm up on Friday into the
weekend with continued quiet conditions.

&&

.NEAR TERM /THROUGH FRIDAY/...
155 AM Update...
Widespread rain showers continue across the Wyoming Valley,
Poconos, and Catskills, but a well-defined back edge to the
precip is evident on radar. This should reach the Wyoming
Valley between 4 AM and 5 AM, and east of the CWA by around 8
AM. Made adjustments to PoPs in the near term.

930 PM Update...
CAMS continues to keep showers rotating through northeast PA
through 09Z, therefore no changes were made to Pops. Drier air
is pushing in over CNY along with parting skies. Temperatures
are beginning to drop off, made slight changes to incorporate
current observations with the forecast.

630 PM Update...
Rain showers have pushed south of CNY this evening with showers
lingering overnight over northeast PA. Radar imagery shows showers
have lightened up in terms of intensity, putting less pressure
on slow draining areas. Made minor changes to update
temperatures and dew points using current observations.
Otherwise the previous forecast remains on track at this time.

252 PM update...
Main concerns in the near term remain focused on the areas of
showers and thunderstorms rotating southeast across the forecast
area later this afternoon and into the evening with locally
heavy rain the main threat...then clear and cool conditions
tonight with patchy fog...quiet/dry conditions on Thursday with
even cooler conditions expected Thu night with more fog
possible.

A slow-moving upper level short wave currently centered over
western PA, stacked on top of the associated surface low, will
pick up speed and move east across central/ern PA this evening
and tonight. This s/w will entrain a fair amount of deep
moisture as it moves east and combine with modest forcing to
trigger a blossoming area of rain showers mainly over north
central PA, but also spread farther north into s- central NY.
PWs advecting into the wave will hover around 1 inch, which is
quite below the average of 1.25" for this time of year. Surface
dew points in the lower to mid 50s are also on the low end of
the spectrum favorable for heavy rain. The amount of forcing and
available mid-level moisture is compensating for these slightly
drier parameters. There is also slow storm-motion and a pivot
point of the upper wave over n-central PA that will contribute
to a longer residence time of the rain showers and subsequent
heavier rain amounts.

Latest mesoanalysis over PA shows an axis of higher instability
with around 500 J/kg of ML CAPE between State College and
Williamsport. There is a broad area of steeper mid level lapse
rates across the region and also SI values around -1 to -2 deg C
which are also allowing for some deeper updrafts and enhanced
convection. We have already had a report of pea-size hail in
one of the storms...which could continue to be a threat along
with isolated cloud to ground lightning through the mid
evening.

The main area of concern through the next 4 hours will be over
northeast PA. Some very isolated heavy rain amounts around 1-1.5
inches are possible as well, which could lead to some localized
brief ponding of water in typical slow-draining areas.

Clouds should clear out tonight as a much drier air mass moves
in. This will combine with light winds, especially areas that
decouple from the boundary layer, and antecedent near-sfc
moisture to produce low clouds and patchy fog. Overnight lows
will bottom out in the lower to mid 40s.

The very dry air mass will continue to filter into the region
tomorrow and allow for mostly sunny skies through the day.
Cannot rule out some afternoon cumulus building up, but should
be more sun than clouds. High temperatures will rise only into
the 60s by the afternoon with breezy NW winds around 10 to 15
mph.

A stronger area of high pressure and large scale suppression
starts to build in from the west Thursday night, and skies will
remain mostly clear, which will set the stage for another
unseasonably cool night and even some patchy fog too. Lows will
fall back down into the lower to mid 40s Fri night.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
325 AM update...

A ridge of high pressure moves into the region Friday night into
Saturday. This will lead to quiet conditions through at least
Saturday night. With heights increasing and flow becoming westerly,
temperatures will trend warmer from the cool end of the work week.
Clear skies should allow for good radiational cooling Friday night,
so this forecast update leaned heavily toward the NBM tenth
percentile. This results in forecasted lows in the 40s. Other than
right at the surface, soundings look too dry for fog to develop even
with light winds forecasted. Temperatures will climb into the 70s on
Saturday. Some valley locations could just exceed 80. Skies will be
sunny as well, so expect a pleasant start to the weekend. With a
much warmer air mass over the region and increasing sky cover,
temperatures will only fall into the 50s.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
325 AM update...

The ridge begins to move east Sunday with the surface high pressure
moving out to sea. A weak shortwave is not far behind and will bring
a low chance for showers across most of the region during the
daytime hours on Sunday. Despite another ridge of high pressure
building into the region by Monday, weak forcing could kick off
isolated showers. Moisture is quite limited though, especially at
the surface, so if anything can develop, it`s possible it just ends
up being just sprinkles or even virga. After Monday, the forecast
becomes a bit more uncertain. Deterministic model guidance has
trended drier with the upper ridge remaining over the region at
least through Tuesday. Ensemble guidance still keeps some rain
chances around. While NBM was initially favored, PoPs were reduced
below guidance. A low pressure system moves into the northern Great
Lakes region by midweek. This will likely be the next system to
impact the region with more widespread showers. But prior to that,
some showers could develop out ahead of this system on Wednesday,
giving us yet another day of chance PoPs.

With cloudy skies and showers on Sunday, temperatures will dip
slightly from the first half of the weekend, only maxing out in the
70s. After that, temperatures warm back up into the upper 70s and
low 80s as 500mb heights increase with the ridge building into the
region. The natural AC during the overnight hours gets turned up as
well throughout this period. Lows will go from the 50s this weekend
to 60s by midweek.

&&

.AVIATION /08Z THURSDAY THROUGH MONDAY/...
Valley fog has developed in otherwise clear areas of Steuben
County, and is expected to start developing around ELM in the
next hour or two as high clouds thin-out. Elsewhere, could see
some brief fog at BGM as the high cloud cover thins out before
dawn.

Widespread rain showers continue at AVP, but the back edge of
precip looks to arrive between 08-09Z. Ceilings and vis remain
VFR, but a brief period of light fog around dawn is possible,
though confidence is low.

Otherwise, from mid morning, VFR conditions and light winds
will prevail through the TAF period across the region.

Outlook...

Late Thursday night through Saturday...Quiet pattern with
mainly VFR.

Sunday through Monday...Small chance of a shower or storm/brief
restriction Sunday and Monday afternoon.

&&

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

&&

$$

SYNOPSIS...BJT
NEAR TERM...BJT/ES/MPH
SHORT TERM...BTL
LONG TERM...BTL
AVIATION...BJT/ES/MPH