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fxus61 kbgm 200842 

Area forecast discussion
National Weather Service Binghamton New York
342 am EST Wed Nov 20 2019

patchy flurries, sprinkles, or drizzle may occur southeast of
Lake Ontario and The Finger lakes today through tonight, during
otherwise quiet and cool weather. Temperatures trend milder
Thursday, ahead of a low pressure system that will bring rain
showers Thursday night into Friday. The weather turns cooler
again over the weekend with chances of rain or snow.


Near term /through Thursday/...
315 am update...
fairly quiet weather is expected in the near term, though a very
Minor Lake response southeast of Lake Ontario could produce
sprinkles-flurries and perhaps patchy drizzle later today
through tonight.

Things are rather quiet currently. The very light radar echoes
in the southeastern zones are virga, with too much dry air in
the 5 to 15 kft agl layer for anything to reach the ground. That
said, there is plenty of stratocumulus under that dry layer,
especially west of Catskills-Poconos. This is helping
temperatures hold up a touch milder than had been forecast.

As northwest low level flow begins to increase this morning,
More Lake moisture will get involved yet with 850mb temperatures
barely cool enough to generate a precipitation response. Spotty
flurries or sprinkles can thus be expected southeast of Lake
Ontario and The Finger lakes later today through tonight. With
that saturated layer still being fairly shallow, we may have a
tough time generating ice crystals within it. Thus we will have
to be mindful of patchy drizzle-freezing drizzle potential for
the few spots that actually get below freezing. Overall
potential for any impact though remains quite low, given warm
ground temperatures. It may turn out to be only very patchy thin
ice of elevated surfaces such as car tops. Highs today will be
mid 30s to around 40. Lows tonight will range from upper 20s to
lower 30s; generally speaking the areas that get below 30
degrees will not be involved with the light spotty lake-induced
precipitation. High pressure will build in through the night,
with the center of the surface high passing to our south but
extending a ridge over US.

The ridge will shove to the coast Thursday, meanwhile low
pressure will be in the western Great Lakes. Between the two,
winds will be shifting to a more southerly direction especially
Thursday afternoon, with warm air advection. Most locations will
get into the 40s; lower elevations of northeast PA to Finger
Lakes New York could even see some upper 40s. Clouds may diminish
initially, only to thicken again in the afternoon as more
moisture streams in ahead of the next system.


Short term /Thursday night through Saturday/...
models appear to be in good agreement with low pressure tracking
through the western Great Lakes into Quebec on Thursday night with a
trailing cold front sweeping across cny/nepa on Friday. Mild air
surges into the area at all levels ahead of the front, and we expect
mainly rain to occur during the first part of this weather event.
Early cooling during the evening Thursday could allow precipitation
to start as a rain/snow mix across Oneida County and the higher
terrain of the western Catskills before temperatures rise
above freezing overnight.

Showers become more numerous along the cold front, mainly Friday
morning across the north central New York counties with generally
scattered/passing shower activity further south into PA.
Temperatures drop fairly quickly behind the front during the
afternoon, and any lingering precipitation is likely to change over
to snow showers and flurries across cny and the northern tier of PA,
while rain showers and sprinkles will generally rule along and south
of I-84.

Temperatures swing from the 40s to lower 50s on Friday morning to
lows in the 20s by Saturday morning.

Saturday looks to be the day between weather systems with diffuse
high pressure spread over the region. Highs Saturday try to climb
back toward normal, but will probably fall just short in the upper
30s to low 40s.


Long term /Saturday night through Wednesday/...
medium range models continue to diverge in handling a high amplitude
trof, and associated low pressure development, moving into the
eastern third of the nation Saturday night and Sunday. Ensemble
spaghetti plots show a great deal of variance, but tonight's 00z
operational European model (ecmwf) and GFS models were agreeing on a more northerly
development of an East Coast low and a big jump in precipitation
chances for our area. Canadian nhemi model is still a miss as is the
mean of the gefs surface pressure and moisture fields. Confidence
remains low, but it's hard to ignore the latest model trends. My
experience tells ME to lean with westward/northward trending and
also tells ME to not jump into the deep end just yet. Nbm blended
guidance still appears to dry in this situation, so have nudged up
pops across the region on Saturday night and Sunday.

Beyond these early periods...quasi-zonal flow brings weak
disturbances and glancing effects of lake effect snow/rain showers
across our northern zones through Tuesday and generally fair
elsewhere. Next...ensemble clusters, including the operational
ec/GFS and Canadian models, point US toward Wednesday and
Thanksgiving day for our next potentially strong system to deal
with. Timing, strength and position of this system is all over the
place with a general tendency for a track again through the western
Great Lakes. That would suggest temperatures leaning on the warmer
side, or at worst marginal, for rain or snow showers depending on
time of day and change of airmass. To sum it all up...rather
unsettled for most days next week, but not unusually cold.


Aviation /09z Wednesday through Sunday/...
winds are currently variable to very light northwest, though
this northwest flow is increasing and will reach to about 5-10
knots later today. Lake moisture is trapped under a developing
subsidence inversion as a high pressure ridge slowly builds in
from the southwest. As of 06z ceilings are fuel alternate kelm,
higher end MVFR at kith, and VFR elsewhere. However, as that
northwest flow increases More Lake moisture will get involved
which along with a lowering of the inversion will get all
terminals to at least MVFR and in the case of kith-kbgm-kelm
fuel alternate to IFR. Spotty flurries and sprinkles can also be
expected for kith-kbgm later this morning to midday courtesy of
combined influences of Lake Ontario and Cayuga Lake. Though krme
should return to VFR this evening, trapped moisture will keep
ceilings fairly stagnant for the other terminals at MVFR to
fuel alternate required levels.


Late Wednesday night through Thursday...lingering MVFR-to-fuel
alternate ceilings for several terminals morning to midday, but
improving to VFR.

Thursday night through Friday...restrictions likely in lower
clouds and rain showers as low pressure system passes.

Friday night...snow showers/flurries could bring restrictions,
mainly the New York terminals. Kavp perhaps an MVFR ceiling.

Saturday...mainly VFR.

Saturday night through Sunday...system with snow-rain mix may
pass through the region with associated restrictions.


Bgm watches/warnings/advisories...
New York...none.



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