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958
FXUS61 KBGM 210142
AFDBGM

Area Forecast Discussion
National Weather Service Binghamton NY
942 PM EDT Tue Aug 20 2024

.SYNOPSIS...
A slow moving upper level low will track across the northeast
United States through mid week with chilly and unsettled weather
for northeast PA and central NY. After this low passes east,
high pressure will build in for the end of the week into the
weekend with fair and warmer weather.

&&

.NEAR TERM /THROUGH THURSDAY/...
-- Changed Discussion --
930 PM Update...

Shower coverage has shrunk with the loss of daytime heating but
with continued NNW flow and the upper low in the area, isolated
showers are expected to continue through the overnight hours in
CNY, with the best chances from the Finger Lakes to Oneida
county. PoPs were slightly lowered in this update through the
overnight as new high res guidance and current radar images
shows smaller precip footprint. The rest of the forecast remains
on track.


620 Pm Update...

NNW flow across Lake Ontario continues to bring scattered rain
showers across CNY. With dry air at the surface, a lot of the
lighter radar returns are virga with stronger cells managing to
break through the dry air and have rain hit the ground. With
continued NNW flow tonight and the center of the upper level low
moving into the area, showers are expected to continue through
the overnight hours and into tomorrow. The current forecast
remains on track, with minor updates to winds and sky cover
based on the latest high res guidance.


330 PM Update...
Radar continues to show pop up showers mainly in north central
NY with much less activity farther south into northeast PA.
Northwest flow off of Lake Ontario was increasing low-level
dewpoints and leading to the showers as there was more
instability with the afternoon heating up there vs. northeast PA
where dewpoints were lower. Hence rest of afternoon will have
higher POPs for showers in NC NY and less farther south. Model
soundings are showing a capping inversion which is limiting the
heights of the convection today and hence no thunder expected.

For tonight, upper level low drops south from Quebec and brings more
wrap around moisture which will combine with lake moisture to
increase chances of showers tonight. For Wednesday, upper level low
will be overhead and it will be chilly aloft. Inversion will be gone
and we will see some CAPE especially downwind of Lake Ontario where
dewpoints will be higher. We expect more widespread showers and even
a few thunderstorms Wednesday and with wet bulb zeros around 5500-
6000 feet we wouldn`t be surprised to see some small hail. This is
an unseasonable chilly airmass with near record low maximum
temperatures. So, Wednesday we will have high POPs which will
be modulated by the heating of the day.

Wednesday night, the activity will linger but be on the wane with
loss of day`s heating. We still will have POPs for showers
though.
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&&

.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY/...
Upper level low will be moving through northern New England with
continued lingering wrap around moisture working across mainly
central NY. NBM seems to be drying conditions out too fast.
Deterministic models hold onto light lake effect rain showers
which is typical in this pattern. So we will increase POPs for
central NY for more light lake effect rain showers Thursday.

For Friday,the upper Level low will finally head east into the
Maritimes. This will put NY and PA under the subsidence region
behind the trough. This will allow a surface high to build in
and our area will dry out with fair weather and more sunshine.
850 mb temperatures will rebound to around 10C which translates
into highs back into the 70s Friday which is more seasonable
for late August.

This high will remain over NY and PA into Saturday with continued
warming trend as southerly flow develops. Temperatures will continue
to moderate with more fair weather which will last into Saturday
night. Upper level trough will approach NY and PA late Saturday
night and could bring a few showers to central NY otherwise it will
be dry. NBM is dry for now and we will keep this in forecast.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
For Sunday, upper level trough passes but it will be fairly dry so
slight chance POPs at this time. Models diverge a bit after Sunday
with GFS having another upper level low stuck under the upper
ridge and other models have much less precipitation through
Tuesday. We will stick close to NBM for this period which is
mainly dry and warm.

&&

.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
Scattered showers continue to move into the region from the
north. Due to this, the Central NY terminals occasionally will
see a shower, though restrictions are not expected. These
showers will continue overnight and through much of tomorrow.
Conditions may become favorable for small hail/ice pellets to
mix with rain tomorrow even though thunderstorms are not
expected. Confidence was not high enough to include in the TAFs
though.

Model guidance does have MVFR ceilings for most of Wednesday at
RME, SYR, ITH, and BGM. It may be like today where clouds are
scattered and it`s VFR at times. Guidance also has Fuel Alt at
SYR and RME briefly, but confidence is low that ceilings will be
that low, so conditions were capped at MVFR for now.

Gusty northwest winds will become calmer overnight. Winds do
become gusty again tomorrow late morning and afternoon with peak
gusts of 15 to 20 kts.

.Outlook...
Wednesday night...Mainly VFR with intermittent MVFR cigs.

Thursday through Sunday...Mainly VFR with high pressure over
the region.

&&

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

&&

$$

SYNOPSIS...DJN
NEAR TERM...DJN/JTC
SHORT TERM...DJN
LONG TERM...DJN
AVIATION...BTL