Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Binghamton New York
958 am EST Thursday Dec 18 2014

Synopsis...
an upper level storm system moving from the Great Lakes to New
England will result in scattered snow showers and flurries this
afternoon. Clouds and seasonably cold temperatures will persist
Friday with scattered snow showers gradually diminishing. Drier
weather is expected over the weekend along with some sunshine.

&&

Near term /through tonight/...
water vapor imagery shows wrap around moisture assctd with the
cyclone near Nova Scotia advecting sewrd across NC New York. This wrap
around moisture will be S and east of c New York by middle afternoon along with
some synoptic scale subsidence. However...there will be continuing
lake effect snow showers downwind of Lake Ontario. 850 mb
temperatures are projected to be around -6c to -7c with lake surface
water temperatures around +5c. This is a marginal set up so not
expecting additional significant lake effect snows. Went for 1-3
inches addnl accumulation in northern Oneida Colorado. Otherwise an inch or
less rest of snow belts in c New York. Very little accumulations
elsewhere in c New York or NE PA expected. There was some multi bands coming off
the east end of Lake Ontario into Oneida Colorado and far northern Onondaga
co/S. This acvty is projected to push southward by afternoon and
weaken. In addtn...some boundary layer heating will pop up some scattered
flurries or light snow showers during the afternoon across much of c
New York and far NE PA mainly downwind of Lake Ontario. Otherwise most
of c New York and NE PA will remain locked in clouds through the afternoon
and tonight. The best shot for some clearing will be across NE PA and
southern Sullivan Colorado...especially from avp-msv and points S and east by tonight. The
winds turn more nearly later tonight and hence expect flurries in
The Finger lakes region.

&&

Short term /Friday through Saturday/...
330 am update...

Big news in the short term as we may actually see some sunshine!
Friday will be cloudy again with plenty of moisture trapped
underneath a very shallow inversion. Lingering flurries possible
but with warming air aloft, it should be short lived. By Saturday the
inversion remains but the thickness of the moisture thins out
enough that we have a realistic shot at sunshine. The 0z Canadian,
which usually handles northwest flow, low clouds well, shows this
scenario well. Increased chances for sunshine Saturday, otherwise
a quiet day is expected.

&&

Long term /Saturday night through Wednesday/...
330 am update...
forecast adjusted accounting for latest wpc guidance. Almost all
guidance has finally abandoned meaningful precipitation chances with weak
wave that traverses west-southwest to east-northeast late Sat night into sun...so while
keeping fair amount of clouds...we have trended probability of precipitation to only
slight chance at best /Canadian still has a scant possibility/.
Thus dry weekend looks likely. Meanwhile...outer edge of weak
coastal system still showing signs of moving through at least a
portion of our region Monday ngt-Tue. With warm air advection aloft
and cold air damming at surface...could include brief period of
-fzra in southeast upslope zones. Precipitation chances have been placed
in 30-40 percent range with that system. Then come Wednesday...for now
we appear to be on warmer side of deepening system...with cutoff
upper low/main surface low positioned over western Great Lakes.
Cyclogenesis of secondary low as it heads somewhere up midatlantic
to northeast regions. Rain appearing likely Wednesday...and then
as mentioned below...a return to colder temperatures later in the
week.

Previous discussion...
followed wpc guidance for the most part. Sat night and sun some
light snow with an inverted trough from a coastal storm well out to
sea. Snow accumulations will be mostly 2 inches or less.

Dry Sun night and Monday with a mild surface high. Monday night and Tuesday models
now trying to bring a weak coastal storm NE into the area with
mixed precipitation. Added some low chance probability of precipitation.

Wednesday a strong occluded front lifts NE ahead of a large bombing
stacked low in the Midwest. Warm air so precipitation mostly rain. This
will need to be watched first for rain amounts and possibly
flooding and second for strong gusty winds.

On the tail end of the steady rain it will change over to snow Wednesday
night and stay cold the rest of the week with wrap around snow.

&&

Aviation /15z Thursday through Monday/...
12z update...
upper wave moved through overnight with west-northwest flow and stubborn MVFR
deck in its wake. In the case of kbgm-ksyr-krme-kith...fuel alt
MVFR ceiling or on its way there. Scattered -shsn mainly from lake effect
this morning krme-ksyr...and then late afternoon-early evening
combined lake moisture plus another weak wave /except kavp/.
Associated visible restrictions generally only limited to MVFR range
because of shallowness of cloud layer will prevent robust ice
Crystal growth. However...tempo IFR visible groups for kith due to
favorable wind flow down Cayuga Lake at time of more enhanced
moisture late afternoon-early evening...and ksyr roughly same time
with moisture off of Lake Ontario. West-northwest to northwest winds today...gusting
upper teens-low 20s kts...then slackening late afternoon Onward to
8-12 kts sustained. MVFR ceiling to persist through tonight for all
terminals...fuel alt request MVFR kbgm-krme-kith with some possibility
of brief IFR ceiling and a flurry.

Outlook...

Friday...MVFR ceiling and perhaps lingering -sn early especially New York
terminals. Ceilings gradually lifting to VFR.

Friday night through Monday...mainly VFR.

&&

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

&&

$$
Synopsis...djn/heden
near term...djn
short term...heden
long term...mdp/tac
aviation...mdp

National Weather Service Glossary of Abbreviations