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fxus61 kaly 190557 
afdaly

Area forecast discussion
National Weather Service Albany New York
1257 am EST sun Nov 19 2017

Synopsis...
periods of wet weather will overspread the region tonight as a
warm front lifts northward across the region. A strong cold
front will sweep across the area Sunday morning, resulting in
windy conditions and falling temperatures. Precipitation will
become less widespread and begin to mix with snow over the
higher terrain. Lake effect snow will occur in favored regions
Sunday night into Monday.

&&

Near term /through today/...
as of 1230 am, regional radars suggest the most concentrated
area of low level jet-forced rainfall is ongoing across the
forecast area and will continue over the next 1-3 hours before
tapering off. P-type is rain in the majority of areas, but a few
spots over Hamilton/northern Warren counties are at the freezing
mark, so an Special Weather Statement was issued earlier for pockets of freezing rain
in sheltered valleys that haven't seen the warm advection
dislodge the shallow cold airmass. Cold front is now crossing
into far western New York/PA and is on track to reach western Mohawk
Valley/Adirondacks around 11z, Hudson Valley around 13z, and
western New England around 14z.

Previous discussion...strong cold frontal passage occurs
through the early morning hours on Sunday. Surface low is
progged to deepen toward 978mb across the St Lawrence Valley as
deformation axis moves across the dacks, Mohawk Valley. A period
of rain/snow transitioning to all snow should commence through
the morning hours Sunday. In addition, winds will quickly shift
to the west-northwest and increase rather quickly in magnitudes.
Mixing layer heights appear to be a little lower than
yesterdays solutions as per close coordination with neighboring
offices, we will issue a Wind Advisory for the southern 2/3rds
of the region. Combination of downsloping, funneling potential
down the Mohawk, into the higher terrain of the Taconics, Berks
and northwest CT should observed wind gusts over 45 mph. Precipitation
should taper off toward noon as the low tracks well north of the
region and deformation weakens.

Then as the cold advection moves across the warm waters of the
Great Lakes (glerl analysis of Lake Ontario temperatures were
near 10c), lake effect snow showers should develop as Delta T/S
climb toward 20c. Per 3kmnam wind trajectories seems 280-290
degree trajectories set up but overall lake band structures and
organization may be delayed a bit as weak mid level short wave
ridge may suppress convective updrafts a bit. That changes
toward Sunday night, however. Temperatures will be falling
through the day as h850 temperatures fall back toward -6c to -8c
with -10c isotherm just upstream.

&&

Short term /tonight through Monday night/...
winds should subside below advisory levels Sunday evening but
still remain gusty. Another upstream short wave approaches
Sunday night as this will be best opportunity for lake effect
snow to develop and impact the region. Trajectories are expected
to remain around the 290 degrees which favors the western Mohawk
Valley and Schoharie valley. Its possible overnight that some of
these bands may migrate into the capital district and favorable
upslope conditions of the Taconics and Berks. At this time,
seems accumulations up to 4 inches are possible for the western
portions of the region with around 1 inch or less expected
elsewhere. Additional adjustments are expected as we watch where
the bands of snow develop and remain persistent. The band(s) of
snow should lift northward toward Monday morning as the
aforementioned short wave lifts east and north of the region and
boundary layer flow backs a bit. So portions of Herkimer and
Hamilton County get some snow Monday morning then as inversion
heights lower, bands should weaken along with warming h850
temperatures toward Monday evening.

A period of warm advection begins to unfold Monday night where
additional cloud coverage is expected. Some upslope light
precipitation may occur into the dacks and southern greens
before much drier air arrives late at night.

As for temperatures, we will blend with the latest ensemble
superblend approach with lows mainly into the 20s and highs
mainly into the 30s.

&&

Long term /Tuesday through Saturday/...
a progressive, northern stream-dominant pattern with fast moving
disturbances looks to continue through much of the long term.

One such disturbance will track from north of the Great Lakes into
northern Quebec Tuesday-Wednesday. Warm advection ahead of this
system should allow for a surge of relatively mild air and above
normal temps for Tuesday, with highs mainly in the 40s to lower 50s,
along with a gusty south/southwest wind. A cold front associated
with this system should track across the region Tuesday night into
Wednesday morning, accompanied by scattered rain showers in valleys,
and rain changing to snow showers across higher terrain late Tuesday
night, with some possible brief lake effect/enhanced snow showers
during Wednesday across portions of the southern Adirondacks/Mohawk
Valley. Mild temps initially Tue night should fall into the 30s by
daybreak Wed, except for some 20s across the western Adirondacks.
Cold advection kicks in Wednesday, although temps may briefly reach
the lower/mid 40s in valley areas in the morning before falling in
the afternoon; with higher terrain areas in the 30s in the morning,
then possibly 20s by late afternoon.

A ridge of high pressure should bring fair and seasonably cool
conditions for Thanksgiving, with highs mostly in the 30s. Then, the
next impulse approaches for Thursday night-Fri am, although it looks
farther north then its predecessor, with weaker overall
forcing/moisture. Perhaps some snow showers across the western
Adirondacks. Lows Thursday night in the 20s in valleys, and teens
for higher terrain; highs Friday in the 30s to lower 40s.

Yet another northern stream system may approach from the Great Lakes
for Saturday, with perhaps some late day and nighttime rain showers
in valleys, and rain/snow showers across higher terrain. Highs Sat
in the 30s and 40s, with lows Sat nt mainly in the 30s. Could be
quite windy again late Saturday into Saturday night, depending on
the ultimate strength of the approaching system.

&&

Aviation /06z Sunday through Thursday/...
numerous showers will continue through around 09z before
activity tapers to showers. Flight conditions vary widely with
kgfl socked in with LIFR stratus, while the remaining sites are
VFR. Expect the very low cigs to persist at kgfl with possibly
some improvement toward daybreak. At the remaining sites,
MVFR/VFR should prevail, but a period of IFR could occur at
kpsf.

A strong cold front is on track to cross through after sunrise,
resulting in a sharp wind shift and strong winds around 14z for
kalb/kpsf/kgfl and around 15z for kpsf. Flight conditions will
continue to improve to VFR in the wake of the frontal passage,
although a few upslope rain or snow showers could occur at kpsf
along and shortly after the frontal passage.

Winds from 06z-12z will range from nearly calm at kgfl/kpou to
southerly gusting to near 25 kt at kalb/kpsf. Low-level wind
shear continues at kgfl/kpou with 40-50 kt winds at 2kft.
Toward 12z, winds will shift to southwesterly immediately in
advance of the front, gusting to 20-25 kt. As the front passes
through kalb/kpou/kgfl around 14z and kpsf around 15z, winds
will shift to westerly and become quite strong through much of
the day, gusting to 30-45 kt, strongest at kalb/kpsf. Winds will
remain elevated but gradually decrease Sunday evening.

Outlook...

Sunday night: moderate operational impact. Windy with gusts to
33.0 scattered rain showers...shsn.
Monday: moderate operational impact. Windy with gusts to 33.0
scattered rain showers...shsn.
Monday night: no operational impact. No sig weather.
Tuesday: low operational impact. Breezy no sig weather.
Tuesday night: low operational impact. Isolated rain showers.
Wednesday: moderate operational impact. Scattered rain showers...shsn.
Wednesday night: no operational impact. No sig weather.
Thanksgiving day: no operational impact. No sig weather.

&&

Fire weather...
periods of wet weather will overspread the region tonight as a
warm front lifts northward across the region. A strong cold
front will sweep across the area Sunday morning, resulting in
windy conditions and falling temperatures. Precipitation will
become less widespread and begin to mix with snow over the
higher terrain. Lake effect snow will occur in favored regions
Sunday night into Monday.

&&

Hydrology...
no hydrologic problems are expected on the main Stem rivers
through next week.

A strong low pressure system will approach from the Great Lakes
region tonight. Widespread wet weather will occur throughout
the forecast area into tonight. A cold front will sweep through
Sunday morning with additional rain changing to snow over the
higher terrain. At this time, total quantitative precipitation forecast from this system looks
to range from a half inch to near an inch, with isolated higher
amounts over portions of the Green Mountains.

A colder air mass will then build in Sunday night through early
next week, with some lake effect snow downwind of Lake Ontario
affecting the western Adirondacks and Mohawk/Schoharie valleys.

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...Wind Advisory from 6 am this morning to 6 PM EST this evening
for ctz001-013.
New York...Wind Advisory from 6 am this morning to 6 PM EST this evening
for nyz038>040-047>054-058>061-063>066-082.
Massachusetts...Wind Advisory from 6 am this morning to 6 PM EST this evening
for maz001-025.
Vermont...none.

&&

$$
Synopsis...bgm
near term...kl/bgm/Thompson
short term...bgm

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