Albany, NY WFO Forecast Discussion

Forecast Discussion for ALY NWS Office
000
FXUS61 KALY 082347
AFDALY

AREA FORECAST DISCUSSION
National Weather Service Albany NY
647 PM EST Wed Dec 8 2021

.SYNOPSIS...
Low pressure will develop off the east coast this evening,
however the storm will be too far east to bring anything more
than a little light snow or flurries to our area this evening. A
weak ridge of high pressure will bring dry, seasonable weather
on Thursday, then a warm front could bring a bit of light snow
mainly north of the Capital District Thursday night. Warmer
weather will arrive on Friday, then very mild weather is
expected on Saturday, along with a good chance of rain showers.

&&

.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
.UPDATE...
Surrounding radars show light snow has overspread entire area.
Updated POPs and WX to account for movement of the upper level
trough and associated snow. Steady snow should end this evening
with maybe some lingering snow showers over eastern areas and
lake effect showers developing over western areas. Temperatures
have remained or fallen below freezing everywhere except right
along the Hudson River in Mid Hudson Valley. Expect some slick
spots out there on untreated roads and sidewalks. Winds are from
a northerly direction and light and so no blowing snow expected
tonight.

PREVIOUS...
A short wave trough moving east from the Great Lakes will spread
some light snow showers east from central NY toward our area
late this afternoon. The trough will also energize an area of
low pressure off the mid-Atlantic coast, and will induce an
inverted surface trough extending northwest from the surface low
toward eastern NY. This low-level feature will likely enhance
the snow shower activity for a while this evening, especially
over the higher terrain of western New England late this evening where
some light upslope northwesterly flow will develop before the
trough moves east during the early morning hours. Meanwhile,
some lake effect snow showers will develop west of the Hudson
Valley overnight as 850 mb temperatures fall below -10 C with a
northwest flow. This combination of features will bring a light
coating of snow to much of the area tonight, with perhaps up to
an inch or two of snow over higher terrain.

&&

.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
A weak ridge of high pressure will build east across the area on
Thursday, cutting off any light lake effect snow early in the
morning and allowing for some sunshine with light winds and near
seasonable temperatures. An approaching warm front will spread
clouds across the area late Thursday and Thursday night. A
period of light snow may accompany the passage of the warm front
late Thursday night, mainly north and west of the Capital
District. Once again, snow amounts will be very light.

A warming trend will begin on Friday with the passage of the
warm front. The flow will turn into the south-southwest allowing
temperatures to climb into the 40s in the Hudson Valley and
upper 30s over the higher terrain.

Low pressure tracking northeast across the western and central
Great Lakes Friday night and Saturday will bring increasing
chances for precipitation to our area Friday night into
Saturday night. At this point, the most likely scenario looks to
be one round of light rain, possibly mixed with sleet or
freezing rain, for areas mainly north and west of the Capital
District Friday night. Saturday will be quite warm and breezy
with many areas climbing into the 50s and even some lower 60s
possible in the Hudson Valley. A few showers will probably
occur, but the day does not look like a washout. A line of
showers will cross the area later Saturday ahead of a strong
cold front approaching from the west. A band of heavy rain and
or strong winds could accompany the passage of the front.

&&

.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
Our impressive cold front will be crossing the region Saturday night
resulting in a sharp temperature drop with even a cold frontal rain
band. Then, gusty winds ensue Saturday night as a strengthening high
from the mid-Atlantic builds northward and takes control of the
Northeast. High pressure remains overhead through at least Tuesday
which will keep seasonably temperatures and persistent dry
conditions in place. Read on for details.

We start off the period Saturday night with our impressive cold
front pushing eastward through the region. Guidance suggests
showalters drop near or even slightly below 0 immediately ahead of
the front which when combined with dew points rising near 50F raises
concerns for some rumbles of thunder. At this time, we chose not to
include thunder mention but will continue to monitor trends and SPC
Convective Outlooks as the event draws closer. Regardless of
thunder, the upstream parent trough swinging through Ontario looks
to become negatively tilted which will enhance the low level
convergence along the incoming cold front and sharpen the
temperatures gradient across the boundary. Therefore, confidence is
increasing that a cold frontal rain band will develop immediately
ahead of the front which could result in a sharp increase in wind
gusts, period of moderate to heavy rain and drop in temperatures. In
fact, BUFKIT profiles show that the incoming cold air mass behind
the front could allow wind gusts to top 40 - 50kts as the sfc winds
shift sharply to the west-northwest. We also note a sharp pressure
rise +10 - 13hPa behind the front as well so the isallobaric wind
contributions could result in wind advisory level winds Saturday
night and will need to be monitored.

The front is very progressive luckily and should exit east of
western New England after 06 UTC. Strong cold air advection behind
the front and westerly flow over Lake Ontario will result in lake
effect snow with snow extending into the western Adirondacks.
Therefore, we show chance and likely POPs reaching into the chimney
of Herkimer County and into northern Hamilton County 00 - 06 UTC
Sunday. However, high pressure building northward from the mid-
Atlantic will likely lower inversion heights and therefore shut off
the lake effect snow by Sunday morning. Otherwise, temperatures
Saturday night will turn chillier in comparison to the mild daytime
Saturday temperatures many will enjoy with lows back in upper 20s to
low 30s.

Breezy winds subside during the day Sunday as the pressure gradient
overhead weakens with high pressure strengthening to 1030hPa as it
moves into the mid-Atlantic. We remain on the northern fringe of the
high which will maintain westerly flow aloft. As a result,
temperatures will still remain slightly above normal with highs
reaching into the upper 30s to mid 40s under partly sunny skies.

Dry and seasonable conditions remain in place Monday through at
least Tuesday as high pressure moves overhead and builds
impressively towards ~1040hPa. With flow aloft mainly from the west,
temperatures will likely stay a bit above normal through at least
the first half of the week.

&&

.AVIATION /00Z THURSDAY THROUGH MONDAY/...
Through 00z Friday...As of 6:45 PM EST, snow has overspread all
of the TAF sites except POU, and snow is expected to begin at
POU momentarily. A steady light snow will fall across the region until
4-5z. This will lead to IFR visibilities over the next 4-5
hours. Ceilings will be mainly MVFR, but some pockets of IFR
ceilings are possible as well. New snow accumulation looks to be
around an inch or less at POU, GFL, and ALB, with up to 2" PSF.
Snow will taper to showers after 4-5z, with lingering MVFR
ceilings expected for a couple hours. However, after 6-7z,
expecting improvement in ceilings and visibilities to VFR, with
VFR conditions continuing through the end of the TAF period. The
exception is PSF where westerly moist upslope flow will keep
MVFR ceilings around through most of the night and into tomorrow
morning. However, by 13-14z tomorrow, expecting improvement to
VFR at PSF too.

Winds are currently at less than 5 kts out of the northeast. Light
north/northeasterly winds should continue until around 4-5z.
However, after the snow ends, winds will shift to the west at 5-10
kts. Winds remain from the west/northwest at 5-10 kts through most
of the day tomorrow, but will become light and variable after
sunset.

Outlook...

Thursday: No Operational Impact. NO SIG WX.
Thursday Night: Moderate Operational Impact. Chance of SHSN.
Friday: Low Operational Impact. NO SIG WX.
Friday Night: High Operational Impact. Likely SHRA.
Saturday: High Operational Impact. Breezy. Definite SHRA.
Saturday Night: Moderate Operational Impact. Breezy. Likely SHRA.
Sunday: Low Operational Impact. Breezy. NO SIG WX.

&&

.HYDROLOGY...
Hydrologically significant precipitation is not expected
through Friday. Cooler weather through Thursday night will allow
ice to form in some waterways at higher elevations.

The next chance of widespread precipitation looks to be from
late Friday night through Saturday, as a warm front then a cold
front move across the region. Available moisture will be well
above normal for this time of year, however the system is
expected to move through quickly which should preclude any
flooding issues. Some river rises are likely to occur as most of
the precipitation is expected to be rain, with greater than an
inch possible.

Drier weather returns Sunday into early next week, which would
allow river levels to gradually recede.

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.

&&

.EQUIPMENT...
The KENX radar will remain down through at least tonight to
refurbish and replace the pedestal.

&&

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

&&

$$
SYNOPSIS...MSE
NEAR TERM...SND/MSE
SHORT TERM...MSE
LONG TERM...Thompson/Speciale
AVIATION...Main
HYDROLOGY...JPV
EQUIPMENT...

NWS ALY Office Area Forecast Discussion