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Area forecast discussion 
National Weather Service Albany New York
421 PM EST Thursday Nov 27 2014

Synopsis...
north upper level disturbance will bring some light snow to
the region tonight with very light accumulations. High pressure
will briefly ridge in tomorrow afternoon with below normal
temperatures into the first half of the weekend. A warm front will
bring some scattered rain and snow showers Saturday night into
Sunday with milder weather to close the Holiday weekend.

&&

Near term /until 6 am Friday morning/...
as of 421 PM EST...a Happy Thanksgiving to everyone...as an upper
level disturbance continues to focus some light snow over the forecast
area late this afternoon. The water vapor loop indicates a piece
of short-wave energy is rotating through the region in the long-
wave trough. The cyclonic flow will continue this evening...and an
inverted surface trough according to NAM/GFS/ECMWF is expected to form
south and east of Cape Cod and southeast New England. As the upper trough
axis interacts with the surface trough...periods of light snow will
continue throughout the night.

The best chance of snow accums of 1-3 inches will be across the southern
Green Mountains of Vermont...and southern dacks. Some likely probability of precipitation were used here.
Most the forecast area north and west of the middle Hudson Valley will
have on and off light snow...and high chance probability of precipitation were used. Some
light accums of a coating to an inch or so by daybreak.

Some weak cold advection will occur in the wake of the upper
trough passage with h850 temperatures falling to -10c to -13c. The clouds
will inhibit a free fall in temperatures. Our min temperatures are in closer
alignment with the NAM MOS values with upper teens to lower 20s
across the forecast area.

&&

Short term /6 am Friday morning through Saturday night/...
tomorrow...the h500 trough axis moves down stream of New England.
West/northwest flow persists in the middle to upper levels. Surface high pressure
will be ridging in from the Tennessee Valley/middle Atlantic region over the
northeast. Some multi bands of lake effect snow showers may sneak
into the northern and eastern Catskills early in the day...but any westerly
upslope snow showers over the southern greens and southern dacks should end early.

Any lake response should be limited in the west to northwest flow...but the
boundary layer flow will begin to back more to the west with the
surface anticyclone building in. A weak connection to Lake Ontario is
expected with some lake effect snow showers for the western Mohawk
Valley and western dacks. Most the rest of the forecast area should be
cold and dry for the big shopping day. Any accumulations will be
light with an inch or less expected northwest of the capital district.
Maximum temperatures will still run a good 10 degrees below normal with highs
in the 30-35f range in the valleys...and mainly 20s over the
higher terrain.

Friday night...any lake effect snow showers off Lake Ontario will
be limited with the inland extent due to the rapid backing flow
and the low inversion depicted on the upstream soundings such as
at kuca in BUFKIT. Lake induced instability will be conditional.
Some light accums will range from a quarter inch to an inch or two
in the western dacks. Most the rest of the forecast area will partly
cloudy...cold and dry with the surface high building in. Lows will be
quite cold in the teens and single digits.

Saturday-Saturday night...the guidance has trended drier for the
majority of the forecast area to open the Holiday weekend with the middle
and upper level flow becoming zonal. A weak impulse in the flat
flow...and an approaching warm front may focus some snow showers
especially north and west of the capital region. There is weak low
level isentropic lift Sat night...so an area of light snow is
possible across the region...especially late. Highs will still be
on the cold side on Saturday with u20s to m30s...and lows will be
in the 20s to l30s Saturday night...but temperatures may on the rise with
the warm front...as its associated surface cyclone moves towards James
Bay...and may move across the region early on Sunday.

&&

Long term /Sunday through Thursday/...
a rather unsettled pattern sets up for the long term with a
relatively fast zonal flow and weak systems passing through the forecast area
for Sunday and Monday with dry weather on Tuesday and another short
wave by Wednesday.

On Sunday a warm front will be lifting northeast from the Ohio
Valley bringing a chance of rain to the area as temperatures will be
relatively mild in the 40s to around 50. On Monday a series on cold
fronts will be crossing the area with mainly rain showers in the
forecast. The lows on Sunday night are expected to be in the 30s
with highs on Monday in the upper 30s to around 50.

Tuesday looks to be the best day of the long term period with high
pressure building across southern Canada. Expect lows Monday night
in the upper teens to middle 20s with highs on Tuesday in the upper 20s
to upper 30s.

On Wednesday another warm front will be working towards our region
bringing more unsettled weather for Wednesday. Lows Tuesday night
are expected to be in the middle 20s to lower 30s with highs on
Wednesday in the upper 30s to upper 40s.

&&

Aviation /21z Thursday through Tuesday/...
weak upper level disturbance moving across the region this afternoon
and this evening will produce conditions varying from VFR to IFR due
to light snow at the kgfl/kpou/kalb/kpsf taf sites. When not snowing
mainly VFR/MVFR conditions expected at the kgfl/kalb/kpou taf sites
through 06z Friday...but MVFR ceilings and MVFR/IFR ceilings expected even
when no snow is iccurring...with VFR visibilities. When snowing at kpsf
expect MVFR to IFR visibilities. From 06z tonight through 18z Friday expect
VFR visibilities at the taf sites...with mainly VFR ceilings.

Winds will be northwesterly at less than 10 kts through Friday.

Outlook...

Friday night: no operational impact. No sig weather.
Saturday: no operational impact. No sig weather.
Saturday night: low operational impact. Slight chance of shsn.
Sunday: moderate operational impact. Chance of rain showers...shsn.
Sunday night: moderate operational impact. Chance of rain showers.
Monday: moderate operational impact. Chance of rain showers.
Monday night: low operational impact. Slight chance of rain showers...shsn.
Tuesday: no operational impact. No sig weather.

&&

Hydrology...
no significant hydrologic problems are expected the next 5 days
ending Tuesday.

Additional light precipitation amounts are expected with basin
averages at a tenth of an inch or less the next few days. Snowfall
accumulations will be a coating to a few inches in a few spots
tonight into Friday.

Milder temperatures are possible Sunday with some snow melt. However...
temperatures are expected to cool off quickly during the day on
Monday with the passage of a strong cold front.

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.

&&

Climate...
a record snowfall of 9.6 inches was set at Albany New York yesterday.
This breaks the old record of 4.9 set in 1888. Also...this places
the storm into the number 5 slot of the top 10 snowstorms for
November for Albany. With additional snowfall expected this
weekend...we will also watch how much adds up to see where we
finish up for snow by the end of the month.

The 10.4 inches of snow at the Albany international Airport places
the snowstorm as number 5 all-time for the month of November.

Top 5 November storms at Albany 1884-2014
amount date year
1. 22.5 inches 24-25 1971
2. 17.3 inches 14-15 1972
3. 14.1 inches 22-23 1943
4. 11.8 inches 17-18 1980
5. 10.4 inches 26-27 2014

&&

Aly watches/warnings/advisories...
CT...none.
New York...none.
Massachusetts...none.
Vermont...none.

&&

$$
Synopsis...wasula
near term...wasula
short term...wasula
long term...11
aviation...gjm
hydrology...bgm/wasula
climate...aly staff

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