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409
FXUS61 KBGM 201827
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
227 PM EDT Fri Sep 20 2024

.SYNOPSIS...
High pressure remains in control through Friday promoting
mainly dry and mild conditions. Showers and thunderstorms are
possible for western parts of the area Saturday afternoon and
evening. Dry conditions return on Sunday, but more showers will
be possible by Monday night.

&&

.NEAR TERM /THROUGH SATURDAY NIGHT/...
1235 PM Update...

Just some minor changes made to the forecast at this time,
mainly raising dew point temperatures this afternoon as we were
running a little low.

925 AM Update...

Allowed for valley fog to linger around a little longer this
morning before it completely burns off. Outside of some minor
sky cover tweaks, the rest of the forecast remains on track
today. Did increase PoPs tomorrow evening over western portions
of our area as a vigorous shortwave moves through.

345 AM Update...

High pressure will be over the region again today. Morning fog
will dissipate by 10 am and give way to mostly sunny skies for
this afternoon. Another warm day is expected with highs in the
upper 70s to low 80s. Skies will gradually become partly cloudy
tonight with some areas of fog forming during the early morning
hours on Saturday. Lows will be in the 50s to near 60 degrees.

Saturday will finally feature a chance for showers and
thunderstorms as a shortwave dives south out of Canada across
Central NY Saturday afternoon. There will be some weak instability
in place with up to 500 J/kg of CAPE by late afternoon. Showers
and thunderstorms are looking more and more likely west of the
I81 corridor with a smaller chance further east. There is very
little shear available, so any storms that do develop will be
weak, but with PWATs approaching 1.5", a quick afternoon
downpour is possible.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
-- Changed Discussion --
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.
-- End Changed Discussion --

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Mainly VFR conditions are expected through the TAF period along
with light winds. Mid and high level clouds will gradually
increase tonight and while areas of valley fog are still
expected overnight into tomorrow morning, it`s not expected to
be quite as widespread as this morning due to the cloud cover.
Confidence is highest at ELM for fog during this time, but given
the increase in cloud cover and model soundings not having the
typical fog look, confidence in visibility reaching less than
1/2 mile is a little lower.

A shortwave will be moving toward the area tomorrow bringing
scattered showers and thunderstorms to areas mainly west of
I-81, but any precipitation and potential restrictions, are
expected to be after this forecast period.

.Outlook...

Saturday afternoon and evening...Scattered showers/thunderstorms
and associated restrictions possible, especially for ELM, ITH
and AVP.

Late Saturday night through Monday...Mainly VFR with valley fog
possible at ELM during the early morning hours.

Monday night through Wednesday...Scattered showers/isolated
thunderstorms and potential restrictions possible as a frontal
boundary approaches.

&&

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

&&

$$

SYNOPSIS...MPK
NEAR TERM...DK/MPK
SHORT TERM...BJT
LONG TERM...BJT
AVIATION...DK