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Area forecast discussion 
National Weather Service Binghamton New York
1044 PM EST Sat Feb 13 2016

dangerous wind chill values will prevail through Sunday
morning...and Arctic air will persist for the remainder of the
weekend. Temperatures will moderate to milder readings Monday. A
large storm system may potentially impact the area Monday night
into Tuesday and may bring heavy snow and possibly a wintry mix.
There is still uncertainty on the track of the storm along with
precipitation type and amount.


Near term /through Sunday/...
1030 PM EST update...
band has managed to quickly reach all the way down to Ithaca-National Weather Service
Binghamton-Windsor line...shifting faster than had been expected.
Forecast was adjusted again around 9pm to reflect this faster
evolution. Not just flurries south of The Finger lakes into the
twin tiers...but likely some accumulation of a half inch to inch
as the band carries through.

715 PM EST update...
lake effect band has persisted across Onondaga...Madison...and
northern Chenango well as slightly into Otsego
County the last couple hours. Hi res model guidance suggests this
will gradually Orient further south the rest of this evening to
involve more of The Finger lakes region...with at least flurries
likely extending even into the twin tiers in narrow bands down
from The Finger lakes overnight. With this Arctic air mass...the
dry fluffy snow is of very high snow-to-liquid ratio and also does
not show up very well on radar being shallow-based and of low
reflectivity. That being said...the bands will continue to lightly
coat roadways where they occur while also reducing visibility well
under a mile at times. Travel with caution. Nobody will enjoy
getting stuck in a disabled vehicle with our dangerous wind
chills. Forecast details adjusted for the above-mentioned
evolution of the lake effect bands...including 1-3 inches or so of
accumulation for much of The Finger lakes to the Cortland-Syracuse

Previous discussion...
lake effect snow showers continue to weaken this afternoon as
very dry and cold air funnels into the region in the wake of a
strong Arctic cold front. Light accumulations are expected. Weak
le showers/flurries may linger through middle afternoon tomorrow. No
impacts are expected from this activity. The main focus of the
forecast period is the extreme cold.

850 mb temperatures continue to fall with temperatures now ranging from -31 near
The Finger lakes region to -25 over the Wyoming Valley. This so far
is the coldest snap of the season which has resulted in surface temperatures
remaining near or below zero across central New York and northeast PA.
Expect 850mb temperatures to fall a few more degrees though the night which
will allow US to see widespread temperatures well below zero tonight. Not
only do we have the extreme cold... but we also have a breezy northwest
wind over the region. The combination of the breezy wind and very
cold temperatures has lead to dangerous wind chill values across the area.
Winds are expected to be 15-25 miles per hour with gusts up to 35mph through
much of the evening. This combination has resulted in wind chill
values reaching as low as -35 degrees. When temperatures reach this type of
value hypothermia and frostbite are possible if proper precautions
are not taken if one chooses to adventure out in this kind of
weather. Thus... the wind chill warning continues for the whole County Warning Area
tonight through Sunday morning.

Thankfully this Arctic snap will modify somewhat Sunday afternoon
with 850mb temperatures reaching -17/-18 degrees. This will allow US to
at least reach the single digits on Sunday for the maximum temperatures. Surface
winds will also gradually weaken throughout the day as high
pressure starts to build over the region thus we lost the
dangerous wind chill values.


Short term /Sunday night through Tuesday night/...
4 PM Saturday update...

The main focus will be on the storm system expected to impact the
region late Mon-Tue.

After quiet weather Sun night-most of Mon, light snow may begin to
streak into at least our northeast PA zones late Monday afternoon,
owing to incoming moisture and warm advection forcing. Model
timing continues to differ in this regard, with the NAM/Gem global
solutions much faster to develop light snow, versus the slower
ec/GFS scenarios.

Higher confidence that steadier precipitation will overspread the
region Monday night, from S to north. Consensus thermal profiles from the
models support snow as the dominant precipitation type at the
onset, with more uncertainty creeping in as we head towards
daybreak Tuesday.

The ec remains the farthest inland/warmest scenario with the
storm, suggesting a snow-wintry mix-rain scenario for a good
portion of the forecast area late Monday night-Tue. However, this is
an outlier solution, as the global model consensus otherwise
shows a track up the coastal plain, with mainly snow from the I-81
corridor westward, and mixed phase potential concentrated mostly
over the Pocono plateau and the western Catskills. At this early
juncture, we're leaning towards the consensus idea of a colder/snowier
event for much of central New York at least. However, out of respect for
the consistent and usually skilled ec, we've retained the
potential of a sleet/freezing rain/rain mix, especially south and
east of a line from roughly Hazleton-Wilkes Barre/Scranton-

The large-scale flow regime suggests that this system could be a
heavy precipitation producer, with an 850-500 mb fetch all the
way from the Caribbean for a time. Thus, stay tuned for the latest
updates, as a high impact event in some way, shape, or form, is
becoming more likely.

Later Tuesday/Tuesday night, as the first system moves away to the
northeast, a clipper type low/short-wave will be approaching from
the west. Although this latter system will lack the moisture
supply/dynamic support of its predecessor, it could still produce
some light snow. At this early Vantage Point, we have chance
probabilities Tuesday night.


Long term /Wednesday through Saturday/...
445 PM Sat update...
in the wake of the potential storm system early in the
week...models are to varying degrees now agreeing on some sort of
clipper sweeping through the region around another
wave rounds the base of the large eastern upper trough. Snow
chances have been increased to the 40-50 percent range and will
probably go up further once timing can be ironed out better. It
might produce a light accumulation. After that...Arctic air will
pay a brief visit Wednesday night through Thursday night...not as
cold as the blast this weekend but still roughly 6-12 degrees
below climatology.

High pressure will likely pass through late Thursday-early
Friday...followed by the warm air advection side of the next
surface low...and associated chance of mixed precipitation later


Aviation /04z Sunday through Thursday/...
the Canadian regional and NAM-12 models are in agreement, keeping
a lake effect snow band over the syr terminal through the next
several hours. Though snow accumulation will be light,
visibilities will range from 3/4sm to 1/4sm under the band.

Elsewhere, mainly VFR conditions will be in place overnight and
through Sunday. Northwest winds will decrease to between 5 and 10
knots after midnight.


Sun night...VFR.

Mon-Tue...restrictions possible in snow or mixed precipitation.

Wednesday...additional restrictions possible in snow showers.



Bgm watches/warnings/advisories...
PA...wind chill warning until 1 PM EST Sunday for paz038>040-043-
New York...wind chill warning until 1 PM EST Sunday for nyz009-015>018-


near term...kah/mdp
short term...mlj
long term...mdp

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