Area Forecast Discussion
Issued by NWS Albany, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
FXUS61 KALY 190228

Area Forecast Discussion
National Weather Service Albany NY
928 PM EST Sat Nov 18 2017

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.


As of 930 PM EST, still isolated pockets of near freezing
temps/dewpoints across portions of Hamilton, northern Warren,
and extreme SE Windham Cos. Southern Herkimer NYS Mesonet obs
finally edging above freezing. Will keep mention of some
freezing rain in these areas over the next 1-2 hours, with
localized ice accretion of up to one tenth of an inch possible.
Since overall coverage is isolated, with coverage continuing to
decrease, have been issuing Special Weather Statements (SPS`s)
to address this hazard/impacts in these areas.

Elsewhere, temps/dewpoints continue to trend upward. Areas of
light/moderate rain continue to stream NE across the region,
with most concentrated/persistent rainfall across the western
Mohawk Valley extending northeast into the Lake George/Saratoga

Still expect periods of rain to occur overnight once any low
level cold air scours out before midnight across isolated
northern areas. As the region becomes well embedded in the warm
sector late tonight, periods of rain should begin to transition
toward showers as temperatures continue to climb through the
40s for many locations. Toward 10-12Z timeframe, per the latest
RAP/HRRR, cold front will be crossing the western Mohawk Valley,
Dacks and Schoharie Valley. Thermal profiles per west-east
cross sections suggest the cold advection should be delayed a
bit so we will hold onto the liquid portion of the forecast at
this time.

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 NW 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

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.


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.


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.


Strengthening low pressure will track across the eastern Great
Lakes into southern Quebec overnight into Sunday. A cold front
associated with this system will cross the area Sunday morning.

Periods of light to moderate rain will overspread the region
this evening, and continue overnight. Moistening of the lower
levels of the atmosphere will allow Cigs to drop to MVFR with
occasional IFR overnight. Vsbys should also dip into the MVFR
ranges, although can not rule out lower Vsbys at times, esp at

The cold front should cross the TAF sites between roughly 12Z-
14Z/Sun. A line of gusty rain showers may accompany or
immediately precede this front, and can not even rule out an
isolated thunderstorm. In the wake of the front, conditions
should improve to VFR, although can not rule out areas of MVFR
Cigs at KPSF into the afternoon. A few passing rain/snow showers
could occur at the TAF sites during Sunday afternoon.

Winds will be mainly south to southeast tonight at 5-10 KT,
although will be stronger at times at KALB, mainly 10-15 KT,
with occasional gusts up to 20-25 KT possible. Winds will shift
into the west, then northwest in the wake of the cold front
Sunday morning, with speeds increasing to 10-20 KT, and gusts of
30-40 KT, strongest and most persistent at KALB and KPSF.

Low level wind shear is likely overnight at KGFL/KPSF and KPOU,
as surface winds remain from the southeast to south at less than
8 KT, while winds around 2000 FT AGL increase from the south to
35-40 KT.


Sunday Night: Moderate Operational Impact. Windy With Gusts To
33.0 Scattered SHRA...SHSN.
Monday: Moderate Operational Impact. Windy With Gusts To 33.0
Scattered SHRA...SHSN.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. Breezy NO SIG WX.
Tuesday Night: Low Operational Impact. Isolated SHRA.
Wednesday: Moderate Operational Impact. Scattered SHRA...SHSN.
Wednesday Night: No Operational Impact. NO SIG WX.
Thanksgiving Day: No Operational Impact. NO SIG WX.


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.


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 QPF 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.


CT...Wind Advisory from 6 AM to 6 PM EST Sunday for CTZ001-013.
NY...Wind Advisory from 6 AM to 6 PM EST Sunday for NYZ038>040-
MA...Wind Advisory from 6 AM to 6 PM EST Sunday for MAZ001-025.


HYDROLOGY...BGM/Thompson is the U.S. government's official web portal to all federal, state and local government web resources and services.