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828
FXUS61 KBGM 270233
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
1033 PM EDT Sun May 26 2024

.SYNOPSIS...
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Our next system moves in late tonight into Monday with locally
heavy rain and a chance for thunderstorms. A few storms may
become severe Monday afternoon. Additional scattered showers
will linger through midweek, with drier conditions expected
towards the end of the week.
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&&

.NEAR TERM /THROUGH MONDAY NIGHT/...

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1030 PM Update...

Updated the timing of the PoPs by incorporating some of the
latest 00z HRRR and 3km NAM; otherwise the forecast remains on
track. The line of strong to severe storms over western PA looks
to dive south and weaken to just rain with a few embedded
rumbles of thunder possible for our CWA overnight.

630 PM Update...

Only minor adjustments to the near term forecast with this
update. Chances were decreased to just low end slight chance for
an isolated t`storm over Sullivan and Pike Counties this
evening. Otherwise, timing was tweaked for the arrival of
showers and t`storms late tonight into Monday. Much of the
morning hours could end up mainly dry on Monday, before showers
and storms quickly develop midday, becoming more widespread in
the afternoon and early evening.

254 PM Update...

Still a fair bit of fair wx cumulus across the area, but expect
cloud cover to continue to diminish for the remainder of the
afternoon. High clouds will begin to increase from SW to NE this
evening, which along with increasing SE winds, should keep valley
fog from developing overnight. There`s still a chance for an odd
shower or thunderstorm to pop up in the Catskills and/or Poconos
this evening, but coverage will be limited.

A shortwave trough, currently bringing thunderstorms to the Ohio
Valley, will move northeast tonight, lifting a warm front northwards
and  bringing a band of showers and isolated thunderstorms across
the area after midnight. Additional rounds of showers will be
possible in a fairly messy warm sector during the morning and early
afternoon hours as additional upper level shortwave troughs move
through, and the broader area ends up under the right entrance
region of a 90 knot jet streak.

The "messiness" of the warm sector will be important later in the
afternoon as it will directly impact the amount of destabilization
that can occur ahead of the main shortwave and prefrontal surface
trough. By early afternoon, bulk layer shear will be around 35
knots, but more critically, 0-1km shear values will be 30-40 knots
across parts of NEPA and into the Catskills. This implies an all-too-
familiar local forecast dilemma of limited instability and high low
level shear which can lead to a tornado or two from a relatively low-
topped and grungy thunderstorm. SPC has put parts of NEPA into the
5% Tornado Risk in the Day 2 Convective Outlook, and has increased
the risk of severe thunderstorms to Slight Risk across all of our PA
counties, with Marginal for the balance of the region.
Destabilization will be key, and this given the shear values, the
greater risk could spread a little further east into the
Catskills, but much depends on how rainfall and cloud cover
holds in during the day tomorrow.

Localized heavy rainfall is also possible, but the risk of flooding
will be mitigated by a fairly progressive storm motion and forcing.
PW values still are on the high side, and spot flooding could still
occur in one or two areas where training of cells occurs. The most
likely area would be near and south/southeast of the I-88 corridor,
but the overall risk is too low for a flood watch at this time.

The heavy rain threat will push east of the area during the evening
hours.
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&&

.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
330 PM Update...

A long wave trough sitting over the NE US will be the main
weather driver for the period, bringing cooler temperatures and
rain showers.

On Tuesday, a shortwave trough will push through the region with
an associated surface low north of the area over Canada. Diurnal
heating combined with the lift from the shortwave will bring a
chance for afternoon rain showers and isolated thunderstorms.
With the weak forcing, lack of deep moisture, and cool
temperatures, severe weather is not expected at this time. Flow
during the day progressively shifts westerly, bringing a cooler
airmass overhead. Temps will climb into the upper 60s to low
70s across much of the region, with some of the warmer valleys
climbing into the mid 70s.

Tuesday night should be dry for most as the trough exits the
region to the ENE. Temperatures will fall into the upper 40s to
low 50s thanks to cool WNW flow. Conditions will not stay quiet
for long as another trough, this time positively tilted, moves
into the region from the NW. This will continue to push cooler
air into the region, with temps on Wednesday only climbing into
the low to mid 60s for most, and upper 60s to low 70s in NEPA.
There is still some uncertainty in the latest guidance as to
how the trough will unfold, with some showing most of the rain
missing us to the south, while others have light scattered rain
showers across the area. Given this synoptic pattern, severe
weather is not expected. The trough swings through the area by
the evening, ushering in much drier air and colder from Canada.
Temps Wednesday night will fall into the low to mid 40s.

&&

.LONG TERM /THURSDAY THROUGH SUNDAY/...
345 PM Update...

A positively tilted upper level trough remains overhead
Thursday into Friday, continuing NW flow and cooler
temperatures for the end of the work week. Suppression from a
surface high building into the region combined with a lack of
moisture in the atmosphere will keep conditions dry. Temps will
be in the 60s for highs and 40s for lows. A strong ridge builds
into the area on Friday night, making for quite a lovely
weekend. Temps will slowly warm as the ridge slides east,
bringing seasonable temperatures for the weekend.

&&

.AVIATION /03Z MONDAY THROUGH FRIDAY/...
VFR conditions will continue this evening with high and mid
clouds increasing tonight, followed by lower clouds as showers
return to the area after about 09Z. A few embedded thunderstorms
are possible as precip returns, but fairly low probability at
any given point. Shower coverage will likely diminish Monday
morning, only to return again towards midday or early afternoon,
with heavier downpours and thunder becoming increasingly likely.
Guidance hints at a short window of IFR ceilings at BGM/AVP as
showers move through, otherwise MVFR to Fuel Alt conditions are
expected at the remaining sites until the end of the period.

Outlook...

Monday afternoon and night...Restrictions likely with locally
heavy rain showers and thunderstorms expected.

Tuesday through Wednesday...Occasional restrictions likely from
multiple batches of showers and thunderstorms.

Thursday and Friday...Mainly VFR.

&&

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

&&

$$

SYNOPSIS...MJM/MPH
NEAR TERM...MJM/MPH
SHORT TERM...JTC
LONG TERM...JTC
AVIATION...ES/MPH