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Area forecast discussion 
National Weather Service Albany New York
926 am EST sun Jan 25 2015

Synopsis...
an Arctic air mass will move across our region today allowing for
much colder temperatures. Another coastal storm is expected to
impact the region Monday afternoon through the middle week period
bringing accumulating snow...some of which may be heavy.

&&

Near term /until 6 PM this evening/...
scattered snow showers and flurries are now from around the
Schoharie valley through the middle Hudson Valley into the Berkshires
and are tending to decrease in coverage as they build south.
Temperatures should hold steady or fall this morning then fall
more steadily this afternoon as the cold advection deepens. Winds
will continue to be gusty as well. Just some minor adjustments to
the forecast through this afternoon based on observations and
trends.

&&

Short term /6 PM this evening through 6 PM Monday/...
a large ridge of high pressure centered over southern Canada will
nose into our region tonight. It will be cold and fair tonight
with lows forecast to range from 10 below zero northwest to around
10 above zero southeast.

On Monday a storm system will move to the middle Atlantic coast
and the track northeastward toward southern New England coast.
This will result in increasing clouds during the morning hours
with snow developing from southwest to northeast across the area
during the afternoon. There is good frontogenetic forcing with
this system and banding of snow is expected especially starting
late Monday. We have some light accumulating snows as far north as
the Mohawk Valley and Lake George Saratoga region for Monday
afternoon. Snowfall totals through Monday afternoon should
generally range from a few tenths of an inch north to around an
inch or so south. Expect highs on Monday to be in the range from
the middle teens northwest to the middle 20s southeast.

&&

Long term /Monday night through Saturday/...
Winter Storm Watch for most of eastern New York and western New England
for Monday afternoon through Tuesday night...

Monday nt-Tuesday nt...the potential for significant impacts from a major
coastal storm continues to increase...especially across western New
England. 00z/25 deterministic models and ensemble suites continue to
support the idea that a clipper type system explosively intensifies
off the northern middle Atlantic coast Monday...and slows its forward
movement as strong upper level energy impinges from the
northwest...allowing for a closed middle/upper level low to form and
capture the intensifying low...and thereby allowing it to possibly
retrograde/loop for a bit southeast of Long Island before tracking
northeastward. The key to this overall evolution appears to be in
part related to a secondary pv anomaly racing east across western
Canada today before diving southeast into south central Canada
tonight and Monday. This pv anomaly helps to induce the closed low
that eventually captures the developing surface low...preventing it from
moving out to sea. There remains some uncertainty in how this
evolves...including how far north and west the surface low potentially
retrogrades as it is captured by the upper level feature. The
00z/NAM and UKMET appear to be outliers at this time with less
capturing and a more progressive evolution...although can not be
completely discarded.

Based on the available guidance...it appears that snow should
develop across southwest areas by Monday afternoon...in association
with isentropic lift. Then...as the surface low rapidly strengthens and
pivots north and west...strong middle level f-general is expected to allow for
bands of snow to move northwest or west across the region late Monday
nt into Tuesday. How far west these bands reach remains in
question...but confidence is high enough at this time for a watch
issuance...with the best chance for heavy snow across western New
England. Should the storm evolve as some of the westernmost guidance
suggest...then widespread heavy snow and strong winds could
eventually encompass much of eastern New York outside of the western
Mohawk Valley and Adirondacks on Tuesday.

Additional refinements will be made to the forecast as newer
guidance becomes available.

Wednesday-Wednesday nt...in the wake of the potential winter storm...high
pressure should translate east across the region...with a break in
precipitation. Temperatures will remain below normal.

Thu-Fri...there is a possibility of another storm system to affect
the region during this time frame...although details are very
sketchy. At the very least...a period of steady snow or snow showers
should move across the region during this time frame. Temperatures will
remain below normal.

Sat...below to well below normal temperatures are expected. Some lingering
snow or snow showers could affect eastern portions of the region.

&&

Aviation /15z Sunday through Thursday/...
an Arctic cold front will pass across the taf sites this morning.
High pressure will then build across the taf sites from the north
for later today and tonight.

Abundant low level moisture pooling ahead of the incoming front has
resulted in areas of MVFR ceilings...along with some snow
showers/flurries. As the front moves through...these snow showers
could briefly limit visibilities into the MVFR/IFR range through 13z-
15z/sun.

Once the front passes...VFR conditions are then expected through
at least 12z/Mon.

West winds will increase to 8-15 knots ahead of the front...with
gusts into the 25-30 knots range possible especially at kalb/kpsf. As the
front passes...winds will veer slightly into the northwest to
north at 10-15 knots for later this morning into the afternoon...with
some gusts possibly reaching into the 20-30 knots range...strongest
at kalb and kpsf. Winds will decrease to less than 8 knots shortly
after sunset.

Outlook...

Monday night: high operational impact. Definite snow.
Tuesday: high operational impact.Breezy definite snow.
Tuesday night: moderate operational impact. Chance of snow.
Wednesday: no operational impact. No sig weather.
Wednesday night: no operational impact. No sig weather.
Thursday: moderate operational impact. Chance of snow.
Thursday night: moderate operational impact. Chance of snow.
Friday: moderate operational impact. Chance of shsn.

&&

Hydrology...
no significant Hydro problems are expected through the middle of
the week. The precipitation that does occur will be in the form
of snow...some of which may east heavy Monday night through Tuesday
evening.

Ice will continue to thicken on rivers...streams...creeks...lakes
and other bodies of water.

The Eagle bridge gage on the hoosic river continues to be hampered
by ice effects.

For details on specific area rivers and lakes...including observed
and forecast river stages and lake elevations...please visit the
advanced hydrologic prediction service /ahps/ graphs on our website.

&&

Aly watches/warnings/advisories...
CT...Winter Storm Watch from Monday afternoon through late Tuesday
night for ctz001-013.
New York...Winter Storm Watch from Monday afternoon through late Tuesday
night for nyz041>043-047>054-058>061-063>066-083-084.
Massachusetts...Winter Storm Watch from Monday afternoon through late Tuesday
night for maz001-025.
Vermont...Winter Storm Watch from Monday afternoon through late Tuesday
night for vtz013>015.

&&

$$
Synopsis...frugis/11
near term...11/NAS
short term...11
long term...kl
aviation...kl
hydrology...iaa/11

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