Gale Warning 144, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
313 PM AKST Tue Dec 15 2020

.SYNOPSIS...
Light snow is falling over much of the Interior and West Coast as
moisture pushes north from a low moving across the Yukon Delta
and another weak low tracking east along the Northern Gulf of
Alaska Coast. Snow accumulations of 1 to 3 inches are expected,
primarily south and west of Fairbanks, with localized higher
amounts. Snow will come to an end Wednesday as both lows move out
of the area and weaken. Otherwise, winds will ease slightly today
over the Interior, with the exception of Northwest Alaska, along
the Chukchi Sea Coast, where blowing and drifting snow may
continue to be an issue. Winds will ramp up again over the
Interior tonight through Wednesday as a cold front rotates south
from a low in the Yukon. This will cause temperatures and wind
chill values to drop across much of Northern Alaska into the
weekend.

&&

.DISCUSSION...
At the surface, models are in good agreement through the short
term, today through Thursday, with the placement of major
features. A 1049 mb high sits north of Utqiagvik while a weak low
tracks through Southwest Alaska and another one across the
Northern Gulf of Alaska Coast. These lows will feed moisture
north into the Interior, increasing chances of light snow today
for much of the Interior south of a line from Northway to Kotzebue
and west to St. Lawerence Island. Snow chances will diminish
through Wednesday as both low weaken and move away from Northern
Alaska. Otherwise, a low retrograding southwest out of the
Canadian Archipelago to the Yukon will swing a cold front south
across the Brooks Range into the Interior, ushering in much colder
temperatures Wednesday into Thursday. In addition, this will
cause winds to pick up across much of Northern Alaska,
potentially creating low wind chill values for the remainder of
the week.

Aloft, at 500 mb, models initialize well with the main features
being a closed 547 decameter (dam) high north of Alaska near 80N
and weak trough across Southwest Alaska into the Northern Gulf of
Alaska. This trough will rotate north into the Interior, aiding
in the development of light snow today. Snow chances will end
Wednesday as the trough weakens and moves out of the area.
Attention quickly shifts to the east, as a 487 dam low over the
Canadian Archipelago retrogrades and extends trough south across
the Brooks Range into the Interior. This will usher in much colder
temperatures across Northern Alaska into the weekend.

North Slope and Brooks Range...
High pressure to the north and low pressure south, a tight
pressure gradient will remain in place across the Arctic Coast
through Thursday. Strong east to northeast winds and blowing snow
issues will continue to impact the Chukchi Sea Coast east along
the Beaufort Sea Coast. Temperatures and wind chill values will
be trending down for the remainder of the short term period.

West Coast and Western Interior...
A low moving through Southwest Alaska into the Bering Sea will
continue to spread light snow over much of the region today into
Wednesday before diminishing as the low weakens and moves over
the Bering Sea. Expect snow accumulations of 1 to 3 inches.
Otherwise, winds will ease slightly today with an increase on
Wednesday, the strongest winds occuring over higher terrain.
Temperatures will begin to cool Wednesday as a cold front sweeps
south across the Brooks Range, decreasing further into the weekend
with the coldest temperatures over the Western Interior.

Central and Eastern Interior...
Light snow has developed over much of the region, expect this to
linger into Wednesday and then come to an end by the evening as
cold arctic air begins to filter in from the Yukon. A chance of
snow in Fairbanks, with the majority of the snow and any
accumulations remaining primarily to the south. Expect snow
accumulations of 1 to 3 inches, highest amounts in the Alaska
Range. Otherwise, winds will ease slightly today and build back
in on Wednesday and Thursday. Increase in winds and a return of
much colder temperatures, wind chill values may dip to the 40s to
50s below for Thursday into the weekend.

Coastal Hazard Potential...
Long range model solutions have a large low moving into the
Bering Sea next week, Monday through Wednesday. There is some
uncertainty with this system, stay tuned to the forecast for
future updates.

Extended Forecast for Days 4 to 7...
Beginning the extended period on Friday, model concensus
continues to show a persistent high north of Utqiagvik that will
drift towards the North Pole with most of the active weather
staying south of Northern Alaska across the Bering Sea and Gulf
of Alaska. Attention shifts to an upper level low retrograding
slowly southwest from the Canadian Archipelago into the Northwest
Territories. As this happens, a surge of much colder air will
flow into Northern Alaska, with 850 mb temperatures on Friday
plummeting to -30C. This shot of cold temperatures looks to be
brief; by Monday, a large low will quickly move into the Bering
Sea causing a drastic warmup as winds aloft become southerly.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Winter Weather Advisory for AKZ201-AKZ203-AKZ204-AKZ219.

Wind Chill Advisory for AKZ220-AKZ221.

Heavy Freezing Spray Warning for PKZ210-PKZ225.

Gale Warning for PKZ225-PKZ230-PKZ235-PKZ240.

Brisk Wind Advisory for PKZ200-PKZ215-PKZ220-PKZ245.

Small Craft Advisory for PKZ210.

&&

RZ DEC 20