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501
FXUS61 KBGM 210750
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
350 AM EDT Sat Sep 21 2024

.SYNOPSIS...
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Chances for rain showers and afternoon thunderstorms expected
Saturday afternoon as a disturbance enters western portions of
Central New York. Thunderstorm chances are highest for areas
west of Interstate 81. Dry conditions return on Sunday, but more
showers will be possible heading into next week.
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&&

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

A shortwave over the Great Lakes will bring chances for rain
showers and thunderstorms into Central NY and portions of NE PA
this afternoon. As it moves into our area, it quickly loses
energy heading into Saturday night. Best chances for rain
showers and a few thunderstorms are for areas west of I-81.
There may be some showers and storms that produce locally more
intense downpours, especially areas west of I-81. High
temperatures of mid 70s to low 80s expected for Saturday.

Dry conditions return Sunday, with high temperatures a little
cooler than Saturday (low 70s to high 70s), thanks to the cooler
origins of the shortwave bringing down slightly cooler air from
Canada.
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&&

.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY/...
230 PM update...
Main concerns in the short term are focused on the slightly and
relatively cooler conditions Sunday with dry/quiet weather
expected, and even cooler air moving in on Monday with
increasing clouds and eventually rain showers from the west.

The synoptic pattern across the Northeast US will be defined by
a narrow ridge of high pressure extending from Nova Scotia
southwest into the mid Atlantic region bordered by an area of
low pressure 300 mi off the coast and an incoming upper trough
getting cut off over the Great Lakes. A narrow corridor of
leftover warm air will be aligned with the ridge along with some
residual low-level moisture. So, as temperatures climb well
into the 70s Sunday afternoon, there will likely be a robust
area of cumulus blossom across the region. However, there should
be enough dry air aloft to limit the vertical growth of
convection, but cannot completely rule out a stray shower in and
around Steuben County.

The surface ridge axis moves slowly to the east Sun night and
Monday as the developing low pressure system in the Great Lakes
starts to inch farther to the east. There is some uncertainty
regarding the onset of rain on Monday, so kept PoPs around 15-20
pct in the morning and 20-35 pct in the afternoon mainly east
of I-81. High temperatures on Monday are expected to be at or
slightly below normal...topping out in the mid 60s to lower 70s.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
230 PM update...
Several rounds of rain showers and isolated weak thunderstorms
are expected Monday night, through the day Tuesday and into
Wednesday as a slow moving/evolving low pressure system over the
mid MS Valley region phases with the Great Lakes low/trough and
lifts northeastward through the GL and into Ontario and Quebec
by Wednesday. The air mass associated with this system is
expected to be fairly mild with 850mb temperatures around +8 to
+11 deg C and plenty of clouds and rain around keeps surface
temperatures mostly in the 60s for highs Tue and Wed and into
the 50s for overnight lows. PWs during this 2 day window are
progged to reach up to 1.5 inches or higher at times, which
could prove supportive for some locally heavy rain. There is
quite a bit of uncertainty when Thursday roles around as the
synoptic pattern is not well agree upon by the model guidance so
there are still a lot of unknowns with respect to both
thermal/moisture profiles and chances for precipitation.

&&

.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR conditions are expected through the TAF period other than
some valley fog at KELM in the several hours up to and
including dawn. Increasing high clouds, along with milder
forecast minimum temperatures, will tend to limit valley fog
production compared to prior nights. It will take longer to get
going at KELM, but most likely scenario is that it will still
ultimately happen even if delayed by several hours. Conditions
are expected to deteriorate to IFR or lower by 10Z. However,
actually reaching to airport minimums will be a challenge.
Whatever valley fog we get will mix out quickly after dawn,
leaving mainly VFR conditions areawide during the day Saturday.
Showers and a chance of thunder may occur prior to 00Z Sunday
west of KSYR- KBGM-KAVP; especially KELM and perhaps KITH.

.Outlook...

Saturday night through early Sunday morning...Scattered showers
and chance of thunder with associated restrictions possible,
especially for ELM-ITH-AVP. After rain ends, shallow deck of
clouds may cause ceiling restrictions for same terminals and
perhaps KBGM into early Sunday.

Sunday midmorning through midday Monday...Mainly VFR.

Late Monday through Wednesday...Multiple chances for showers
and isolated thunderstorms with associated potential
restrictions as disturbances pass through the region.

&&

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

&&

$$

SYNOPSIS...KL
NEAR TERM...KL
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...KL