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Area forecast discussion 
National Weather Service Buffalo New York
653 am EST Monday Jan 26 2015

low pressure will move through the Ohio Valley and middle Atlantic
today and spread a steady light snow into much of the region except
the north country. This will produce accumulations in most areas
before tapering off to scattered snow showers early Tuesday. A
strong low along the East Coast may produce some light snow east of
Lake Ontario Tuesday and Tuesday night but will otherwise miss our
region. High pressure will bring a brief break on Wednesday before
another low brings a widespread snow on Thursday.


Near term /through tonight/...
light snow starting to spread into the southern tier and expect is
to slowly fill in and build northward.

Surface low from West Virginia to South Carolina will jump to
offshore of the Virginia convective available potential energy as large scale ascent and DPVA
overspread the coastal front and force low level cyclogenesis. A
broad area of warm advection will continue to overspread most of our
region...supported by a modest 30-35 knot southerly 850mb jet from
the western southern tier into the Genesee Valley and Finger Lakes
which will provide some added lift and convergence. A broad middle
level trough will provide some large scale support as well...with
combined influences of left exit regions of two jet streaks to our
west and east..

The snow will reach the New York state thruway corridor from Buffalo to
Rochester by middle morning...then spread north to the South Shore of
Lake Ontario by late morning. A persistent northeast feed of dry air
across the north country should keep most of the snow at Bay across
Jefferson and Lewis counties with just thickening middle level clouds.

Expect additional amounts of 2-4 inches today from the western
southern tier into southern Erie/Wyoming counties and east into the
Genesee Valley and western Finger Lakes. 00z GFS and 03z sref have a
more westward bias than previous model runs so will expect more snow
to impact the buf and roc areas as well as the deformation zone
backs westward overnight. Another 2 to 3 inches overnight west of
The Finger inch or two along the southern Ontario shore
with an inch or less across the north country.

High temperatures today will be limited to the middle to upper teens under
a persistent cold northeast flow. Lows tonight will be in the lower
teens for most locations and the single numbers to near zero east of
Lake Ontario.


Short term /Tuesday through Wednesday night/...
by 12z Tuesday the coastal storm will be located southeast of Cape
Cod near the 40n/70w benchmark. The western edge of the deep layer
moisture should be displaced to the east of the area. This will
allow for a diminishing trend to the snow. North-northeast flow
between the coastal low and expanding surface high from northern
Ontario across Lake Ontario will maintain some potential for minor
accumulating snows to continue during the first half of the
day...although lowering inversion heights will limit accumulation
potential to less than 2 inches. Temperatures will remain below
normal with highs in the teens to lower 20s.

The coastal storm will weaken and lift out Tuesday night with a
continued diminishing trend to the snow across eastern portions of
the area. Clearing skies...light winds will bring a cold night with
lows in the single numbers above to some locations down into the
single numbers below zero.

Surface ridging will build over the region Wednesday and Wednesday
night providing dry conditions with a good amount of sunshine during
the day Wednesday. Anticipating some degree of diurnal response
which should support daytime highs in the 20s.


Long term /Thursday through Sunday/...
global models remain in good agreement with the next storm system to
shift across New York and the lower Great Lakes in the
Thursday-Friday timeframe. This low center tracking just south of New
York with sub-freezing vertical temperature profiles will favor an
accumulating snowfall. Dry and cold weather will start the weekend
Saturday with high pressure and shortwave ridging passing by then
12z GFS and European model (ecmwf) models diverge with timing the arrival of the next
Arctic blast to open February. The 12z European model (ecmwf) shows -25c 850mb air
ushered in with an Arctic front on Sunday/Sunday night while the 12z
GFS delays this coldest air until Tuesday behind an early week Great
Lakes cutter. Have followed wpc and surrounding offices keeping
temperatures on the cold side of guidance with a chance of some snow


Aviation /12z Monday through Friday/...
snow will is beginning to overspread the western southern tier near
the PA state line...and is expected move northward to the South
Shore of Lake Ontario by late morning. Once the light snow
begins...visibility will quickly deteriorate to IFR...but with MVFR ceilings.
The light snow will then continue through the rest of the day with
visibility varying between 1-3 miles. The snow will have a sharp northern
edge...and probably not reach the north country including kart
through this afternoon. This MVFR ceiling and MVFR/IFR visibility pattern
will persist through the evening and tonight.

Tuesday...areas of MVFR with light snow tapering off to flurries.
Wednesday...mainly VFR.
Thursday...a chance of snow and associated IFR.
Friday...areas of MVFR with a chance of snow showers and brief IFR
especially southeast of the lakes.


northeast winds will increase today as low pressure moves across the
middle Appalachians and re-develops off the East Coast...with high
pressure moving east across Quebec and producing a moderate pressure
gradient across Lake Ontario. This will produce Small Craft Advisory
conditions along the South Shore of Lake Ontario from about Sodus
Bay westward from later tonight through at least Monday night...and
possibly into Tuesday.


Buf watches/warnings/advisories...
New York...none.
Marine...Small Craft Advisory until 10 PM EST Tuesday for loz042-043.
Small Craft Advisory from 4 PM this afternoon to 10 PM EST
Tuesday for loz044.



near term...wch
short term...tma
long term...Smith

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