425
FXUS61 KALY 180728
AFDALY

Area Forecast Discussion
National Weather Service Albany NY
228 AM EST Thu Dec 18 2025

.WHAT HAS CHANGED...
Cold frontal passage timing on Friday will be a little earlier
with the strong gusty winds shifting from the south to southwest
to west in late morning into the early afternoon across eastern
NY and western New England with falling temps through the day.
Precipitation will transition from rainfall to snowfall west of
the Hudson River Valley in the late morning the greatest
accumulations of the southwest Adirondacks.

&&

.KEY MESSAGES...
1. Above normal to potential record breaking temps ahead of a
potent cold front will lead to a period of rain and snow melt
tonight into Friday morning.

2. There is the possibility for some urban and poor drainage
flooding due to the rain and snowmelt early Friday.

3. Strong gusty winds are likely tonight into Friday morning,
especially for high terrain areas, which may result in downed
trees and power lines. A second surge of strong winds with the
cold frontal passage may lead to additional area-wide impacts.

4. Frigid conditions return Fri night thru weekend into the mid
week and accumulating light snow will be possible through early
next week for much of the area.

&&

.DISCUSSION...

KEY MESSAGE 1...
The calm before the storm will occur today with a sfc
anticyclone over NY and New England moving down stream this
afternoon into tonight. A vigorous mid and upper level trough
will be digging into the Upper Midwest, MS River Valley and
Southeast early tonight. A strong sfc cyclone will be lifting
northeast of Lake Superior into southern Ontario tonight.
Meanwhile, downstream over the East Coast the mid and upper
level ridging will begin to break down, as strong south to
southwest flow will develop over the region. An infusion of
milder air from the Deep South will surge up the Coast over the
region with rising temps tonight from the 30s and lower 40s.
Temps will continue to rise Fri morning into the 40s to lower
to mid 50s before a sharp cold front moves through.

In the deep south to southwest flow, an anomalous south to
southwest low-level jet /LLJ/ increases at H925 to 40-55 KT and
H850 to 50-75 KT. The latest NAEFS V-wind /southerlies/
anomalies continue to be +3 to +4 standard deviations /STDEVs/
above normal advecting moisture in from the Gulf and western
Atlantic. As the isentropic lift increases ahead of the warm
front, expect periods of rain to quickly develop shortly before
midnight and continue overnight. The winds at the mtns and
ridge tops should be very strong despite an inversion on the
soundings. We continued the Wind Advisory for the region and
discuss specifics below in Key Message #3. The anomalous nature
of the air mass needs to be emphasized, as the record high for
Albany is 54F set in 1895. We will be real close to that temp
Fri morning. H850 temps will be 1 to 2 STDEVs above normal ahead
of the cold front and the actual temps look to be in the +5C to
+8C range by 09Z to 15Z FRI. The cold front has a strong
thermal gradient with it. The theta-e difference is impressive
at the sfc and h850 in the 12Z-18Z FRI time. A few
thunderstorms may pop-up from Albany, the northern Taconics and
the eastern Catskills south and east into the mid Hudson Valley,
southern Taconics, Berkshires and NW CT. SPC continues a
"General Thunderstorm" forecast and we have slight chance
/15-20%/ probabilities in these areas. The instability is
elevated and small but the forcing is strong with the boundary.
The thunderstorm threat may need to be expanded further north
through the entire area later. Initial rumbles of thunder may be
ahead of the warm front, but some of the CAMs like the 3-km
HRRR and 3-km NAMnest do show a strongly-forced narrow cold
frontal rainband zipping across the region from west to east in
the 12Z-18Z time frame (some slight timing differences). It`s a
high shear and low to little CAPE environment. A severe threat
can not be ruled out with the impressive dynamics and shear in
place. Temps will plummet across the forecast area, as colder
initially polar air gushes back into the region turning the pcpn
over to snow over the southwest Dacks, western Mohawk Valley
and northern and eastern Catskills. A few inches will occur
especially over the higher terrain by nightfall. Some totals may
reach 2-4" over the western Dacks by early Sat morning.

The winds ahead of the front will be south to southwest 15-30
mph with gusts 35-50 mph. The winds will shift to west at 15-30
mph with gusts 35-50 mph in the afternoon/early evening. Temps
will fall into the 20s and lower 30s by the early evening. The
cold advection will continue through the overnight with blustery
winds with lows in the teens to lower 20s and some single digits
in the Adirondack Park.

Overall, the moderate to locally heavy rainfall event will
produce some snowmelt with the gusty winds and warm temps, but
the latest 01Z NBM still shows a 45-80% chance for 1" of
rainfall for most of eastern NY and western New England by early
Fri evening with the lowest chances over the western Mohawk
Valley/western Dacks. Some accumulating snow on the the order of
an inch or two may also occur over the southern Greens, northern
Taconics and Berkshires Fri pm/early evening with coating to a
few tenths in the valleys especially on the grassy surfaces.

KEY MESSAGE 2...
The snow melt combined with the rainfall will cause some
ponding of water on roadways and some rises on rivers, creeks
and brooks. The majority of the rainfall or QPF will occur Thu
night into Fri in a 12 to18-hr window. Snow depths in the
south/southwest Adirondacks range from 8-20" and the southern
Greens 6-16" based on the latest NOHRSC. Many valley areas have
a coating to less than 5". The strong southerlies and the
rainfall may melt a lot of the snow pack in the valleys causing
ponding and poor drainage flooding in low-lying areas. Some
melting, movement and break-up of ice may occur on rivers. Ice
on the northern most basins ranges from 3" to 9" based on the
NERFC guidance, which is thick for this time of year, so the ice
jam threat looks somewhat low with only a brief spell of milder
weather. The snowpack may ripen or compact due to absorption
over the higher terrain/mtns, but the latest rainfall forecast
is for 0.75"-1.25" over most of the forecast area with 1-2" over
the eastern Catskills. River Flooding is not forecast, but poor
drainage or urban flooding may occur in some of the valley
areas. WPC has a "Marginal Risk" for excessive rainfall in their
latest Fri-Fri night graphics from Albany north and east.
Frigid air will sweep back in Fri night which will dry things
out and freeze up any standing water. Some drains may get
clogged with ice, garbage or even leaves that remain from the
Fall which may cause urbanized flooding.

KEY MESSAGE 3...
As described earlier, the LLJ will not only advect in moisture
and milder temps but also cause wind damage. H850 winds of 50-75
KT from the south to southwest may translate to the surface
especially over the higher terrain over western New England, the
eastern Catskills and the narrow south to north valleys merging
into the Mohawk River Valley. The question remains how well the
winds puncture through a duct or stable layer. It looks like
the best time may be between 09Z-15Z/FRI where some of the 10-m
winds on the MAVMOS for Bennington jump up to 29KT! The
conceptual model with cool season CSTAR UAlbany back in 2010
for high wind and severe events fits well here, as with the
warm conveyor belt we could see at least advisory level wind
gusts 46-57 mph especially in the high terrain areas. We will
have to monitor if an upgrade is needed to at High Wind Warning
which is for wind 58 mph or greater for any of the high terrain
areas.

If convection occurs, then short-fuse SPSs or SVRs may be
needed, and then we get into strong cold advection in the
afternoon/early evening in the wake of the front. Area-wide
gusts 35-55 mph will be possible, as the rapid surface pressure
rises will be occurring with the deepening cyclone well to the
north and west over southeast Canada. It will be after dark, but
strong momentum transfer from 3-5 kft AGL with the surface rapid
pressure rises and cold advection may allow gusts which could
bring down large tree limbs, some large trees, and power lines
causing some power outages. The Wind Advisory looks good, but
parts of the area may need to be expanded to a High Wind Warning
later. The highest NBM 24-hr Max gust probabilities (QMD) > 50
mph for the 24-hr period ending 1 am Saturday are over the
eastern Catskills, Greater Capital Region, northern Taconics and
the Berkshires. The winds should begin to subside between 1 am
and 7 am Sat.

KEY MESSAGE 4...
A frigid air mass opens the weekend with high pressure building
in from the south late Fri night into Sat morning. After
morning lows mainly in the teens and 20s, max temps will only
recover into the mid and upper 30s in the valleys with 20s to
lower 30s over the higher terrain. The mid and upper level flow
becomes zonal with the next clipper arriving Sat night into Sun.
The disturbance looks like it will take a more northerly track
so the greatest threat for snow showers will be over the
northern zones north of the Mohawk Valley and Capital Region
with light accums of snow. A non-diurnal trend of temps will
likely occur Sat night with temps rising from the 20s and lower
30s, but then temps will fall during the day with the cold front
moving through. Highs may be near normal before tumbling.

Brisk and cold conditions occur Sun pm into Sun night with lows
the teens with a few single digits over the Adirondack Park and
lower 20s in the mid Hudson Valley. A frigid air mass will be
over the region Mon with max temps about 10 degrees or so below
normal with highs in the 20s to lower 30s with some teens over
the southern Greens and southwest Adirondacks. Another clipper
and its warm front may bring a more widespread light
accumulating snowfall late Mon night through Tue. Some impacts
could occur with the potential holiday travel before Wed and
Thu. Snowfall amounts may range from a half inch to two inches
over most of the region with higher amounts over the southwest
Dacks and southern Greens. Below normal temps continue into
Christmas Day on Thu.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
Through 06z Friday...VFR conditions prevail across all terminals
this morning as clouds have cleared out of their boundaries with
the exception of a thin layer of mid-level FEW clouds. Mostly
clear to clear skies will prevail overnight, yielding persistent
VFR conditions at KPSF and KPOU. However, due to melted snow
today and elevated dewpoints, KGFL and KALB could see some fog
later on this morning. Included TEMPOs for possible IFR
conditions here between the hours of 09-12z.

Any fog that develops this morning should mix out quickly such
that VFR conditions return and remain in place for the remainder
of the 06z period. Winds will be primarily south to
southeasterly today with sustained speeds ranging from 5 to 10
kt. KALB could, however, see sustained speeds reach 15 kt with
paired gusts up to 25 kt.

Outlook...

Friday Night: High Operational Impact. Very Windy With Gusts To 40 kts. NO SIG WX.
Saturday: No Operational Impact. NO SIG WX.
Saturday Night: Moderate Operational Impact. Chance of SHSN.
Sunday: Low Operational Impact. Breezy. Slight Chance of SHRA...SHSN.
Sunday Night: Low Operational Impact. Breezy. NO SIG WX.
Monday: No Operational Impact. NO SIG WX.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for
     CTZ001-013.
NY...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for
     NYZ032-033-038>043-047>054-058>061-063>066-082>084.
MA...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for
     MAZ001-025.
VT...Wind Advisory from 7 PM this evening to 1 AM EST Saturday for
     VTZ013>015.

&&

$$

DISCUSSION...15
AVIATION...37