000
FXUS61 KBGM 162003
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
403 PM EDT Thu Sep 16 2021

.SYNOPSIS...
Mainly dry conditions will persist through Friday, although a
few isolated showers cannot be ruled out, especially for the
Poconos and Catskills. A weak cold front will move through the
area on Saturday, leading to some scattered showers and
thunderstorms. Then a several day period of warm and dry
weather is expected for the first half of next week.

&&

.NEAR TERM /THROUGH FRIDAY NIGHT/...
330 PM Update:

High pressure continues to bring mostly sunny skies across the
majority of the area. However, with a frontal zone to our
southeast, lingering cloud cover has led to a partly sunny to
mostly cloudy afternoon across the Poconos and Catskills. A
brief pop-up shower cannot be ruled out late this afternoon into
this evening for those areas, but otherwise the majority of the
area will remain dry.

Tonight, low pressure off of the Carolinas will be drifting
northward, while high pressure remains largely in control.
However, with an east to southeast low level flow between these
two features, low level moisture will push farther north and
west, allowing for expanding cloud cover. The cloud cover will
be most widespread across Northeast PA-Catskills, but may also
reach the Southern Tier of NY. In addition, patchy fog is
expected overnight/early Friday morning, especially in the
valleys. Lows are expected to be in the upper 50s to mid 60s.

The above mentioned low pressure system off the Mid-Atlantic
coast will continue to slowly move northward on Friday. Some
moisture will be pulled northward into portions of our region,
allowing for a low chance for some isolated to scattered showers
and possibly a few afternoon thunderstorms. The greatest chance
for this will be east of I-81 (mainly across the Poconos-
Catskills). However, without much of a lifting mechanism
present, expecting any convection to be rather isolated in
nature, with the majority of the area remaining dry. Otherwise,
expecting partly sunny skies with highs in the mid 70s to lower
80s.

With the loss of diurnal heating, along with the low pressure
system pulling farther offshore, expecting any lingering
isolated showers to quickly end by early Friday evening.
Meanwhile, a weak cold front will be approaching the area from
the west. This front may cause a few isolated showers to develop
late Friday night/early Saturday morning, especially across the
northern Finger Lakes. Otherwise, partly to mostly cloudy skies
are expected with lows in the lower to mid 60s.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
A weak cold front will push through the region Saturday morning.
The best chance for precipitation will be during the peak heating
hours in the afternoon. The forcing environment along the front is
much stronger north of the area, so CAPE will drive the development
of rain showers and isolated thunderstorms. Guidance indicates
afternoon values from 1000-1500 j/kg ahead of the front. Bulk shear
looks to be lacking, with values maxing out around 20kts. These
ingredients will allow for pulse thunderstorms to be the main
mode of convection for the afternoon. PW values around 1.25in
will help keep the heavy rain chances low. Highs on Saturday
will reach the mid to upper 70s in the valleys and low 70s on
the hilltops.

Much drier and cooler air will filter in behind the front Saturday
night into Sunday morning as high pressure builds in from the west.
Ample moisture at the ground will provide for patchy fog across the
area, especially in the valleys. Lows will drop into the mid 50s.
Fog should lift after daybreak.

Sunday is expected to be a beautiful day with clear skies, light
northerly winds and temps in the low 70s. The northerly winds will
keep the humidity at bay so expect it to feel wonderful outside.
Overnight, clear skies and dry air will allow for very efficient
radiational cooling, dropping temperatures to the upper 40s to low
50s. Another round of fog is expected during the early morning
hours.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
A very strong ridge of high pressure will migrate across the CWA and
by Monday morning we will be on the back side of the high and the
flow will shift to out of the south. This will advect warm, moist
air in from the south through Wednesday. For high temps during the
early part of the week, I went above guidance blended in some 90th
percentile temperatures from the NBM on Monday and Tuesday. Backing
this up was 925 mb temps across the area around 20C, which would
suggest highs in the upper 70s to low 80s. Deep, strong high
pressure systems tend to be more efficient at heating up an area
than the models suggest, and this situation is a great example as
deterministic guidance had temperatures 6-8 degrees colder than the
NBM. Lows will be in the mid to upper 50s through Wednesday.
Moisture advection and winds decoupling from the boundary layer
will allow for fog formation, but at this time, confidence on
the fog strength is low. I wanted to get the chance of fog
development in the forecast and we will evaluate it as the event
approaches.

Wednesday and Thursday will be our next chance for active weather.
An upper level low pressure system will spill out of the Rockies and
travel across  the northern US during the early part of the week.
The strong high over our area will impede the progression of
this wave, but differences in guidance is still too far apart
for any clarity on how it will unfold. An arrival between
Wednesday morning and Thursday morning is currently likely, but
went with NBM guidance because of this uncertainty in time of
arrival.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
Mainly VFR conditions are expected at all terminals through this
evening. Marine layer moisture will then bring lowering ceilings
late tonight/early Friday morning at all terminals except for
KSYR. Best chance for IFR restrictions will be at KAVP, KBGM,
and KELM. At KELM, is a bit uncertain if restrictions will be
from low ceilings or fog, but either way, IFR-or-worse
conditions are likely there late tonight. Conditions will
gradually improve by late Friday morning.

There is a slight chance for an isolated shower at KAVP late
this afternoon into this evening, but potential for this is too
low to include in the TAF there at this time.


Outlook...

Friday afternoon through Saturday...Small chances of scattered
showers/isolated thunder with associated brief restrictions.

Saturday night through Tuesday...VFR, except late night-early
morning valley fog probable beginning Sunday night for at least
KELM; possibly others.

&&

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

&&

$$
SYNOPSIS...BJG
NEAR TERM...BJG
SHORT TERM...JTC
LONG TERM...JTC
AVIATION...BJG

NWS BGM Office Area Forecast Discussion