617
FXUS61 KALY 281752
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
1252 PM EST Fri Feb 28 2025

.SYNOPSIS...
Breezy and cooler today with a clipper tonight bringing light
to moderate snow accumulations mainly north of Interstate 90
while brief initial snow turns to rain elsewhere. A strong cold
front then pushes through the region during the day tomorrow,
ushering in unseasonably colder temperatures and breezy
conditions along with additional snow showers. Dangerously cold
temperatures are possible Saturday night and Sunday night in
higher terrain areas.

&&

.NEAR TERM /THROUGH TONIGHT/...
Key Messages:

- Clipper system tonight will result light to moderate snow
  accumulations for areas mainly north of Interstate 90. There
  is around 20 to 40% probability that snowfall amounts exceed
  4 inches or winter weather advisory criteria in the southern
  and western Adirondacks.

Discussion:

As of 1252 PM EST...Visible satellite imagery shows mostly
clear skies over eastern New York and western New England. Some
clouds can be seen just west of the region over western NY, as
both cu/stratocu from lake moisture and some high clouds can be
seen. Through the afternoon hours, cloud cover will increase, as
some of these higher clouds move into the region from the west.
Otherwise, it will be dry through the late afternoon hours.

Good mixing has been allowing for gusty winds so far today, with
westerly winds gusting 20-30 mph at times, especially within the
Mohawk Valley, Capital Region and Berkshires. It will stay
breezy through the daylight hours, but these winds may start to
decrease towards evening with the loss of daytime
heating/mixing. Highs today will be in the mid 30s to mid 40s
for most spots, although some parts of the Adirondcks may hold
in the upper 20s to low 30s. Temps should start to fall off this
evening.

A clipper system will quickly be approaching from the west for
tonight. With temperatures this evening starting off in the 20s
to low-30s, the incoming precipitation will initially arrive as
snow for most. Snow first spreads into the western/southern
Adirondacks and western Mohawk Valley by 00-03 UTC before
advancing eastward further into the Mohawk Valley, Capital
District, Upper Hudson Valley and southern VT by 03-06 UTC.
Areas south of I-90 will be farther removed from the forcing and
moisture so steady precipitation looks to miss these areas with
just some light showers grazing them. Snow turns moderate
across the southern and western Adirondacks through 06 UTC as
strong low and mid-level winds upslope the terrain resulting in
enhanced precipitation amounts/intensity. In fact, the HREF
shows probabilities for 1"+ per hour snowfall rates reaching up
to 30 to 40% during this window.

Southerly winds tonight will advect the clipper`s warm sector
northward and allow temperatures to trend warmer through the
night. Thus, expect a non-diurnal temperature trend with
overnight minimums occurring in the evening before rising into
the mid to upper 30s by sunrise Saturday. The incoming milder
air mass will also result in SLRs trending downwards favoring a
wetter type of snow. After 06 UTC, the strongest warm air and
moisture advection exits to our north and the dry slot within
the warm sector surges northward. This means the initial period
of snow will trend to scattered light rain showers with shower
coverage diminishing overnight. The southern Adirondacks and
southern Greens remain as wet snow.  Overall, expecting coating
to 1.5 inches of wet snow for most areas from I-90 northward
into the northern/eastern Catskills, Taconics, and western MA
with 3 to 6 inches in the southern Adirondacks and spine of the
southern VT. Winter Weather Advisories remain in effect the
Hamilton and northern Herkimer County.

&&

.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
Key Messages:

- Initially mild temperatures Saturday morning rapidly turn
  colder through the day Saturday with rain showers along a cold
  front ending as wet snow. Any wet surfaces can refreeze and
  turn icy Saturday afternoon into Saturday night.

- Cold Weather Advisories may be needed Saturday night and
  Sunday night especially in the western and southern
  Adirondacks where the feel-like temperatures or wind chill
  values may fall to -15F to -20F.


Discussion:

The clipper`s cold front then marches eastward Saturday morning
reaching western zones by around 12 UTC allowing snow to turn
steady again in the southern/western Adirondacks. Southerly
winds ahead of the front allow temperatures to turn quite mild
early to mid Saturday morning with many rising into the low to
mid 40s, even spiking to upper 40s to low-50s in the mid- Hudson
Valley and NW CT. The incoming cold front features a strong
thermal and moisture gradient as well as strong low-level
convergence as a much colder air mass moves in behind it.
Therefore, a line of initially rain showers immediately ahead of
the boundary could turn to wet snow depending on how quickly
temperatures fall. Highest chance for additional snow
accumulations look to be in the southern and western Adirondacks
and southern Greens where temperatures will be colder resulting
in an additional 1 to 2 inches. The strong low level forcing
and even weak sfc buoyancy as the front arrives during peak
heating could support some burst of heavier snow in some of the
hill towns and higher terrain areas where temperatures are
colder. A flash freeze will also need to be monitored as any wet
surfaces could quickly turn icy Saturday afternoon/evening as
temperatures rapidly fall from the 40s into into the upper 20s
to low 30s. West to northwest winds quickly turn gusty behind
the front reaching up to 30 - 40mph so breezy winds will help
dry out surfaces.

Winds shift to the northwest Saturday evening in the wake of our
trough axis with the true surge of cold air rushing into the
area. Winds stay gusty overnight with upslope and lake effect
showers spreading into western Mohawk Valley, southern/western
Adirondacks, and southern Greens. Luckily, the northwest wind
shift will direct most lake effect snow showers to our south in
the Catskills. Temperatures turn quite cold overnight thanks to
the strong cold air advection that ensues with the incoming air
mass ranging 2 to 2.5 standard deviations below normal per the
NAEFS. Overnight lows fall into the single digits and teens
with sub-zero reading in the southern/western Adirondacks.
Breezy winds weaken overnight but will still make it feel even
feel even chillier, more like -10F to 0F. The southern and
western Adirondacks may reach cold weather advisory criteria as
the feel-like temperatures reach -15F to -20F.

It will be very cold Sunday into Sunday night as our unseasonably
cold air mass (850hPa isotherms ranging -18F to -22F) remains
overhead. Daytime highs struggle to rise out of the teens and
low 20s for most of eastern NY and western New England while
the southern Adirondacks only rise into the single digits.
Probabilities for temperatures to rise 25F or higher on Sunday
are virtually zero expect in the mid-Hudson Valley and southern
parts of Litchfield County. Northwest winds remain a bit breezy
which will make it feel even chillier but winds trend downwards
through the day as high pressure builds into the Northeast.
Skies remain mostly to partly sunny and turn clear overnight as
high pressure moves overhead. Efficient radiational cooling
will support very cold overnight lows between -10F and +10F with
even negative teens in the southern Adirondacks. While winds
will be much lighter, with such cold temperatures in place, even
a light wind will lead to dangerously cold temperatures. Thus,
additional cold weather advisories may be necessary in higher
terrain areas.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
Key Message:

- Temperatures will moderate from below to above normal Monday
through Thursday.

- A prolonged, widespread rainfall event is anticipated Wednesday
through Thursday. Confidence is medium to high in at least 0.5"
regionwide with the probabilities for such having increased to ~60-
80%. And while confidence remains low to medium in accumulations
equating to or exceeding 1", the probabilities for such have also
increased regionwide to ~20-50%.

Discussion:

Tranquil, but cool conditions open the extended forecast period
Monday with high pressure encompassing the region at the surface and
shortwave troughing exiting aloft. High temperatures Monday will,
therefore maintain the below normal categorization with widespread
20s to 30s expected outside of pockets of upper 10s at the highest
elevations of the Southwest Adirondacks, Southern Greens and
northern Berkshires. As the surface anticyclone shifts south and
east out of the region Monday night, lows will fall to the single
digits to 10s with pockets of low 20s in the lower Mid-Hudson Valley
and southern Litchfield County.

Some uncertainty lies in the forecast for Tuesday as latest guidance
is beginning to hint at a weak clipper sliding east across southeast
Canada that could lead to some scattered rain and snow showers, or a
mix thereof throughout the day. With weak ridging in place, it`s
possible that most of the showers could remain confined to higher
terrain areas where southerly upslope flow could help to overcome
subsidence beneath the ridge. For now, maintained scattered chance
to chance PoPs for light showers regionwide. High temperatures
Tuesday will be in the 30s and 40s. The main focus of the long term
period then comes for its remaining two days as confidence continues
to increase in a prolonged, widespread rainfall event beginning
possibly as early as late Tuesday night/early Wednesday morning.

By Tuesday evening, a large-scale, positively-tilted, southern-
stream trough will span much of the central CONUS with a northern
stream shortwave trough axis digging into the northern Plains. A
deepening surface cyclone beneath the primary trough will become
situated around the Central Plains/Midwest regions with a southwest
to northeast-oriented moisture fetch taking shape off the Gulf along
the leading edge of said trough. Anomalous moisture (PWATs on the
order of +2 to +2.5 STDEVs; IVT on the order of +3 to +4 STDEV) will
surge into the region as the once again deepening low tracks north
and east through the Midwest into the Great Lakes/Ohio Valley
regions. Warm air advection ahead of the attendant warm front will
allow a widespread precipitation shield to spread into the region
from west to east by late Tuesday night/early Wednesday morning.
While the predominant precipitation type will likely be rain,
depending on the onset time, some snow, a rain/snow mix, or even
some pockets of mixed precipitation could occur within the Southwest
Adirondacks and Lake George-Saratoga region. Confidence at this
point is highest in the occurrence of some snow mixed in with rain,
but will continue to monitor the potential for freezing rain as lead
time decreases given the anticipation of warm air advection
providing what could end up being a requisite warm nose. Regardless,
daytime warming and persistent warm air advection will allow any
wintry precipitation to change over to rain with embedded bands of
FGEN leading to moderate to potentially locally heavy rainfall rates
at times especially in the upslope regions our higher terrain
through Wednesday afternoon. Moderate to locally heavy rates will
also be possible in the Mid-Hudson Valley and southwest New England
given the adjacency to the divergent left exit region of the 55 to
65 kt LLJ hugging the Mid Atlantic/Long Island/New England
coastlines through Wednesday. This is not to say that moderate to
locally heavy rainfall rates are not possible elsewhere. With 850 mb
temperatures surging to +6 to +8C, warm cloud processes could also
allow for some embedded heavier downpours outside of the
aforementioned, more favored areas.

Periods of rain continue through Thursday as the surface cyclone
gradually weakens as it traverses the eastern Great Lakes and
continues north and eastward into Quebec, its associated trough also
filling to the north and east aloft. Behind the warm frontal passage
Wednesday evening, a cold front will swiftly swing through the
region by Thursday morning allowing dry air to filter in on the back
side of the system and inducing cold air advection that will lead to
a change over to primarily snow or a rain/snow mix for any lingering
showers through Thursday evening. When all is said and done, QPF
looks to reach about 3/4 of an inch to one inch with isolated,
locally higher amounts of up to an inch and a half in the Eastern
Catskills. At this time, confidence is medium to high in at least a
half an inch of QPF with probabilities for such ranging from about
60-80% throughout the region. The probabilities for at least one
inch decrease significantly from this, but have increased since the
last iteration of this forecast with 20-50% across the region. The
greatest of these probabilities lie in the Eastern Catskills, Mid-
Hudson Valley, and western New England. At this time, the
aforementioned northern stream shortwave does not look to phase with
the primary system. The environmental set up does not favor this so
it is not anticipated that this expectation should change. However,
should this happen, QPF amounts could increase. But given that this
is still well into the extended, QPF amounts are already subject to
change. We will continue to monitor this storm closely for hydro
concerns especially due to potentially significant snow melt.

&&

.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
Through 18z Saturday...Primarily VFR conditions will be seen across
the region through this afternoon. This evening, clouds will be on
the increase with a clipper system approaching the region early
tonight, which is expected to bring snow to several terminals.
Confidence on snow occurring is highest at KGFL, where a period of
IFR conditions have been maintained for this TAF. Confidence on
impacts from snow further south at KALB/KPSF is low as CAMs disagree
on position of the snow, so continue to maintain PROB30 groups for
drops to IFR conditions at these locations. Once the clipper exits,
conditions will return to VFR to MVFR (this favored more at KGFL
before conditions improve late). A strong cold front approaching
late in the period may bring a renewed round of brief rain and snow
showers late Saturday morning, but confidence on timing is low and
precludes mention in the current TAF. West to northwest winds
gusting around 20-25 kts this afternoon will become light out of the
south to southwest tonight under 10 kts this evening and tonight.
The arrival of the cold front late Saturday morning will bring a
shift to northwest winds with gusts around 20-30 kts.

Outlook...

Saturday Night: Moderate Operational Impact. Windy With Gusts To 34 kts. NO SIG WX.
Sunday: Low Operational Impact. Breezy. NO SIG WX.
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. Slight Chance of SHRA.
Tuesday Night: Moderate Operational Impact. Chance of SHRA.
Wednesday: High Operational Impact. Definite RA.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...Winter Weather Advisory until 4 PM EST Saturday for NYZ032-033.
MA...None.
VT...None.

&&

$$

SYNOPSIS...Speciale
NEAR TERM...Frugis/Speciale
SHORT TERM...Speciale
LONG TERM...Gant
AVIATION...Speck