Winter Weather Advisory 39, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
645 AM AKST Wed Mar 3 2021

.SYNOPSIS...
A weak shortwave rotating around an upper level low continues to
produce areas of light snow this morning over the Interior which
will continue into the afternoon hours. Strong north winds will
ease later this morning along the West Coast as ridging builds
in. Elsewhere, for the North Slope, bitterly cold temperatures
will remain locked in through Thursday, before a warmup ensues
Friday.

Attention shifts back to the West Coast, where a strong
storm will bring blizzard conditions and high winds to St.
Lawrence Island late Wednesday night and to the West Coast by
Thursday.

&&

.DISCUSSION...
At the surface, models are in good agreement with the placement
and strength of major synoptic features. A 983 mb broad area of
low pressure over the Gulf of Alaska will continue to weaken and
pull away from Northern Alaska as the day progresses. Ridging
over the Bering will slide east today across the West Coast and
to the Eastern Interior by Thursday. This is ahead of strong 964
mb low moving into the Gulf of Anadyr Thursday, with a front
extending south through the Bering Sea. This front will reach St.
Lawrence Island late tonight, then the West Coast Thursday
morning, and into the Western Interior by Friday. This front will
quickly fizzle out Friday as it moves into the Central Interior.

Aloft, at 500 mb, models initialize well with a deep longwave
trough encompassing Northern Alaska with ridging building over
the Bering. The longwave trough tries to hold on over the Eastern
Interior as the ridge pushes east over the region Friday. This
ridge is being nudged east by a deep 468 decameter low that tracks
to just west of the Gulf of Anadyr Thursday morning, this will
push a deep trough across the Bering Sea and into the West Coast
Thursday afternoon. Then across the Western Interior late Friday
with ridging building back in over the West Coast.

North Slope and Brooks Range...
A weak shortwave rotating northwest along the Beaufort Coast is
bringing some clouds and light snow to the area. Temperatures
this morning once again dipped into the 20s and 30s below for many
locations across the region. These temperatures coupled with
gusty winds, wind chills still remain dangerously cold across the
North Slope and Brooks Range, with the coldest wind chills
occuring through Brooks Range Passes where a strong north gradient
remains. This gradient will ease this afternoon and then switch
southerly Thursday afternoon. A strong front will move into the
Chukchi Sea Thursday, tightening the gradient and bringing strong
east to southeast winds along the Chukchi Sea Coast, producing
areas of blowing and drifting snow. Winds ease Friday as the front
sweeps northeast along the Northwest Coast, bringing a chance of
light snow from Point Lay north to Utqiagvik.

West Coast and Western Interior...
Snow across the YK Delta will continue to taper off this morning
as the system responsible continues to track southeast into the
Gulf of Alaska. Strong north winds, causing areas of blowing and
drifting snow along with bitterly cold wind chills, will ease
this morning along the West Coast as ridging builds in across the
region and into the Western Interior this evening. Attention
quickly shifts to the Bering where a strong front pushing east
will first impact St. Lawrence Island late tonight, the West
Coast Thursday morning, and then inland into the Western Interior
Friday morning. This front will bring strong southeasterly winds
accompanied by heavy snow and blowing snow, with the worst
conditions impacting St. Lawrence Island late tonight and then
the YK Delta and Seward Peninsula Thursday morning, producing
widespread blizzard conditions.

Central and Eastern Interior...
Satellite imagery this morning depicts vast cloud cover across
the area this morning, along with areas of flurries as a weak
trough continues to lie overhead. This will support flurries into
the afternoon before tapering off as the upper level trough
rotates out of the area, generally less than one inch of snow
expected. The pressure gradient will tighten this morning across
the Alaska Range, creating gusty north gap winds along with
blowing and drifting snow. Ridging will move into the region
Thursday, ahead of a strong front that pushes into the Central
Interior, a tight pressure gradient will once again develop along
the Alaska Range late Thursday into early Friday, creating strong
southerly gap winds that may approach advisory criteria.
With the ridge in place over the Eastern Interior, the strong
front that pushes into the Central Interior will stall and weaken,
keeping snow chances well west of Fairbanks for friday.

Coastal Hazard Potential for Days 3 and 4...
No concerns at this time.

Extended Forecast for Days 4 through 7...
Beginning the extended period on Saturday, active weather will
persist over the Bering east across the West Coast into the
Western Interior as a series of fronts impact the region. While
the Central and Eastern Interior along with the North Slope
remains relatively benign as ridging dominates conditions.
Temperatures will moderate as flow aloft turns southerly and
brings a surge of warmer air the spreads across all of Northern
Alaska by early next week.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Blizzard Warning for AKZ207-AKZ213.

Winter Storm Warning for AKZ214.

Winter Storm Watch for AKZ209-AKZ210-AKZ211-AKZ212.

Wind Chill Advisory for AKZ206-AKZ208-AKZ217.

Storm Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ220-PKZ225.

&&

RZ MAR 21