Winter Weather Advisory 20, NWS Albany, NY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1242 AM EST Fri Dec 17 2021

.SYNOPSIS...
A cold front will move across the region tonight with some
scattered rain showers. Cooler, mainly fair, and breezy
conditions are expected on Friday. Low pressure moving south of
the area through Pennsylvania and New Jersey will bring snow,
sleet, freezing rain and rain to our area Saturday and Saturday
night.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
.UPDATE...Cold front continues to push east/southeast across the
Mohawk Valley and Saratoga region, about to enter the Capital
District, northern Catskills and southern VT. Not much shower
activity with the front, although wind gusts in the 25-35 mph
range have been common from NYS Mesonet and ASOS obs. Current
forecast on track, with only minor adjustments needed for the
rest of the overnight.

.PREVIOUS[1001]...Cold front now working across New York State
into our forecast area. It now extends from just west of Lake
Champlain across northern Herkimer and northwest Hamilton
Counties, southwest across the Finger Lakes. Temperatures
initially dropping slowly behind the front, but cooling will
accelerate after 08z. Satellite shows little cloudiness behind
the front so clearing looks to be quick. Winds will be gusty
later tonight with and behind the front.

Warm temperatures will continue this evening with southerly
flow. The system's cold front will move across the area
overnight with gusty westerly winds developing which will really
get temperatures falling. Overnight lows will be higher than
normal highs for mid-December. Expecting lows in the 30s mainly
above 1500 feet and in the Mohawk Valley with 40s below that
with some 20s in the portions of the southern Adirondacks.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY NIGHT/...
Snow and a wintry mix, sleet and freezing rain, Saturday into
Saturday night. Moderate snowfall possible mainly north of
I-90.

Fair and continued mild Friday but not a warm as today in the wake
of the cold front. It will be breezy. Flow aloft will become quasi-
zonal with some weak ridging building in.

The center of a surface high passes to our north across eastern
Canada Friday night into Saturday extending southward across the
local area as it does. This will result in a northerly flow of
colder into the region which will help set the stage for the
precipitation over the weekend.

Initially a primary low over the Ohio Valley will track east-
northeastward across western and central New York Saturday with a
secondary low developing over the mid-Atlantic region. The secondary
low will become the primary low Saturday evening as the cutting off
the warm air.

Isentropic lift increases Saturday morning with the atmosphere
saturating and precipitation developing and moving in. Chances for
precipitation will be increasing late Friday night into early
Saturday morning. Have pops increasing to likely in the vicinity of
I-90 by mid to late morning and categorical by early afternoon.

Initially snow is expected with some rain possible in the mid-Hudson
Valley due to boundary layer temperatures. Guidance has trended a
colder with the warm nose not penetrating as far northward as
previously expected.  There are some timing differences with the
warm nose moving across the region Saturday evening and how far
north it gets so used a blended approach creating the weather grids
using the top-down method. Expecting snow north of I-90.
Precipitation will be transitioning mainly Saturday afternoon and
evening south of I-90 with sleet and freezing rain across the higher
terrain and in the vicinity of I-90 with rain in the mid-Hudson
Valley into northwestern Connecticut. As the coastal low heads
eastward of away from the coast colder air will be drawn back in
and a transitions back to snow will occur as precipitation
lightens and tapers off during the afternoon hours.

At this time, expected 4 to 6 inches north of I-90 with less
than an inch in the mid-Hudson Valley into northwestern
Connecticut. Glaze of ice accretion across the eastern
Catskills, Helderbergs Schoharie Valley into portions of the
Mohawk Valleys, across the Taconics, Berkshires, Litchfield
Hills and into some of southern Vermont. Winter weather
advisories will be needed.

Highs are expected to occur early Saturday evening with readings in
the lower to mid 30s below 1000 feet and in the 20s across the
higher terrain. Temperatures will drop into the 20s Saturday night.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...
Saturday's system will be moving off to our east to begin the long
term Sunday. Drier weather is expected to return for Monday as a
split flow regime looks to remain in place for most of next week.
Other than a weak clipper system Monday night or Tuesday, drier
weather should continue until Thursday or Friday when another
clipper system could bring some light precip to the region. More
details below...

Long term period begins Sunday with the Saturday's system departing
off to the east. We will see cold air advection with a northwesterly
winds as the surface low moves off to the east. This may result in
some lake effect snow showers for western areas, with northwesterly
flow trajectories favoring the Mohawk Valley and Catskills. Some
upslope snow showers will also be possible in the southern Greens
and Berkshires. Snow showers look to diminish during the afternoon
as the low continues to pull away from the region and high pressure
begins to build in from the west. Highs will range from 20s for the
high terrain to mid/upper 30s in the valleys. Sunday night, high
pressure from the west moves into the region with rising heights
aloft. This will create favorable conditions for radiational
cooling, especially with many areas having a fresh snowpack from the
recent storm. Lows are currently forecast to be in the single digits
for the northern 1/3 or the region, with 10s elsewhere, but these
lows may be need to be adjusted downward in the coming days if
confidence in favorable radiational cooling conditions increases.

High pressure will remain in control Monday with mainly zonal flow
aloft, resulting in tranquil weather. Highs will be in the 20s and
30s once again. However, Monday evening or Monday night, we switch
to a warm advection regime as a northern stream/clipper system is
expected to pass just to the north of our region. Moisture will be
quite limited with this system, but some additional clouds are
expected Monday night, and will mention slight chance to low-end
chance PoPs for our northern Adirondack zones with this clipper
system into early Tuesday morning. This will result in warmer lows
than the previous night, with temperatures only expected to drop
into the 10s and 20s.

Tuesday and Wednesday, high pressure remains in control ,keeping us
mainly dry. This part of the long term will feature a split flow
regime. A potent southern stream system will move off the southeast
coast during this timeframe; earlier this week there were signals
that this storm may move up the east coast, but it now appears that
the northern and southern streams will remain separate, keeping this
system well to our south with dry weather for our region. Highs both
days will be in the 20s and 30s with some low 40s possible in the
Mid Hudson Valley tuesday. Overnight lows will be cold each night
(single digits possible in the Adirondacks, 10s to 20s for the rest
of the region) with high pressure overhead.

Thursday, another northern stream clipper system will move towards
the region, although there is some uncertainty regarding the timing
of this system. Nevertheless, will mention chance PoPs for northern
and western areas with slight chance PoPs for the rest of the
region. At this time, will just mention snow showers for northern
areas and include a rain/snow mix for the valleys, but precip type
obviously remains highly uncertain at this lead time. Highs should
once again range from 20s in the high terrain to upper 30s elsewhere
with some low 40s possible in the Mid Hudson Valley.

&&

.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
A cold front will move east/southeast across the TAF sites
through 08Z/Fri. High pressure briefly build across the TAF
sites from the northwest during Friday.

Mainly VFR conditions are expected for through Friday
afternoon. As the cold front crosses the TAF sites over the next
couple of hours, a few sprinkles and Cigs of 4000-6000 FT AGL
are possible, followed by clearing skies.

Some patchy MVFR Cigs are possible Friday evening, especially
at KPSF, as a weak secondary front settles southward, with Cigs
possibly in the 2500-3500 FT AGL range at KGFL, KALB and KPSF.

South to southwest winds will shift into the west/southwest
behind the front, and increase to 8-12 KT with gusts of 20-25 KT
possible, especially at KALB and KPSF where a few gusts may
briefly approach 30 KT. Mainly west winds will persist into this
afternoon at similar speeds, before veering into the
west/northwest and decreasing to 5- 10 KT with gusts of 15-20 KT
Friday evening.

Low level wind shear will remain possible before the cold front
passes, given south/southwest surface winds at generally less
than 10 KT, with winds around 2000 FT AGL from the
west/southwest at 30- 40 KT. If any locations have surface winds
decrease less than 10 KT after the front passes, then LLWS may
persist longer, perhaps until daybreak (with the best chance of
this occurring at KPOU).

Outlook...

Friday Night: Moderate Operational Impact. Chance of SN.
Saturday: High Operational Impact. Definite RA...SN...SLEET.
Saturday Night: High Operational Impact. Definite SHSN...RA...SN...SLEET.
Sunday: Low Operational Impact. Slight Chance of SHSN.
Sunday Night: No Operational Impact. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.
Monday Night: No Operational Impact. NO SIG WX.
Tuesday: Low Operational Impact. Breezy.

&&

.HYDROLOGY...
Only some scattered light rain showers are expected tonight with the
passage of a cold front. Our next chances for precipitation will
come this weekend, Saturday and Saturday night, as a low pressure
system impacts the region. Much of the precipitation is expected to
come in the form of snow or a wintry mix with a changeover to plain
rain possible in valleys from around Albany southward. Any runoff
that occurs would only result in minor river rises.

Mainly dry and colder weather returns Sunday into early next week.

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...
New Record High Temperatures were set yesterday...

Glens Falls, NY: Today's high of 57 degrees breaks the
previous record of 56 degrees set in 1982.

Albany, NY: Today's high of 61 degrees breaks the previous
record of 55 degrees set in 1971.

Poughkeepsie, NY: Today's high of 64 degrees breaks the
previous record of 59 degrees set in 1971.

Record high minimum temperatures for December 16:

Glens Falls, NY: 37 degrees, 2011. (40 degrees breaks record,
2021)

Albany, NY: 45 degrees, 1971. (45 degrees tied record, 2021)

Poughkeepsie, NY: 41 degrees, 2015. (41 degrees tied record,
2021)

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.

&&

SYNOPSIS...SND
NEAR TERM...IAA/SND/JPV
SHORT TERM...IAA
LONG TERM...Main
AVIATION...KL
HYDROLOGY...IAA
CLIMATE...

Hazardous Weather Outlook
National Weather Service Albany NY
413 PM EST Thu Dec 16 2021

NYZ032-033-041>043-082>084-VTZ013>015-171200-
Northern Herkimer-Hamilton-Northern Saratoga-Northern Warren-
Northern Washington-Northern Fulton-Southeast Warren-
Southern Washington-Bennington-Western Windham-Eastern Windham-
413 PM EST Thu Dec 16 2021

This Hazardous Weather Outlook is for the southern Adirondacks, Lake
George northern Saratoga Region and Washington County in eastern New
York and southern Vermont.

.DAY ONE...Tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

A low pressure system will move eastward across the region Saturday
into Saturday night. This system is expected to bring a moderate
accumulation of snow with a brief wintry mix. Winter Weather
Advisories may be needed later in time.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.

CTZ001-013-MAZ001-025-NYZ038>040-047>054-058>061-063>066-171200-
Northern Litchfield-Southern Litchfield-Northern Berkshire-
Southern Berkshire-Southern Herkimer-Southern Fulton-Montgomery-
Schoharie-Western Schenectady-Eastern Schenectady-Southern Saratoga-
Western Albany-Eastern Albany-Western Rensselaer-Eastern Rensselaer-
Western Greene-Eastern Greene-Western Columbia-Eastern Columbia-
Western Ulster-Eastern Ulster-Western Dutchess-Eastern Dutchess-
413 PM EST Thu Dec 16 2021

This Hazardous Weather Outlook is for northwestern Connecticut,
western Massachusetts, the Mohawk Valley, Greater Capital Region,
Schoharie Valley, eastern Catskills, Helderbergs, mid Hudson Valley,
and the Taconics of eastern New York.

.DAY ONE...Tonight.

There is a low probability for widespread hazardous weather.

.DAYS TWO THROUGH SEVEN...Friday through Wednesday.

A low pressure system will move eastward across the region Saturday
into Saturday night. This system is expected to bring a light accumulation
of snow and sleet transitioning to freezing rain and plain rain.
Winter weather advisories may be needed later in time for the wintry
mix.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is not expected at this time.