Winter Storm Watch 25, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
638 AM AKST Sat Dec 4 2021

.SYNOPSIS...
Strong high pressure is causing clear skies and temperatures in
the 30s and 40s below across the Eastern Interior that will become
less severe Sat night and Sun as clouds approach from the west.

A weather front that lies along the West Coast of Alaska will lift
north and weaken this morning. Strong winds and blizzard or near
blizzard conditions occuring with this front along the West Coast
will diminish early this morning as the front lifts north and
weakens.

A low just west of Shemya, which contains the remnants of a
tropical storm, will deepen very rapidly as it moves into the
Bering Sea today and taps into very cold arctic air off of Russia.
This will bring southerly gale and storm force winds, along with
heavy snow and blizzard conditions, to St Lawrence Island this
evening, then spreading to the remainder of the West Coast late
tonight and Sun. Heavy snow and localized blizzard conditions
will spread into the Western Interior on Sun. Expect 8 to 18
inches of snow across the West Coast and Western Interior by the
time the storm tapers off on Mon. This will also bring strong
winds and cold winds chills to the Brooks Range, Alaska Range, and
Eastern Interior tonight through Mon.

The strong south winds over the Bering Sea today and tonight, will
become southwest on Sun and remain southwest into Mon. This will
cause sharp rises in sea levels along the West Coast of Alaska
from the Bering Strait south starting early Sunday, and will
bring the possibility of coastal flooding. Sea levels could rise
4 to 6 feet above normal along the West Coast from the Bering
Strait south, which could flood low lying areas along the coast
and cause ice to pile up on the beach. Although there is extensive
sea ice in this area, the ice is highly fractured and will likely
only partially dampen the storm surge, and could pile up on the
beach. People along the coast from the Being Strait south should
move boats and valuables away from the shore to prevent damage
from sea ice and minor flooding. This should be done today, before
the next blizzard hits.

Surface...
A strong weather front along the West Coast of Alaska will weaken
and move east today. A low just west of Shemya will move to the
Western Bering Sea as a 966 MB low by 3pm Sat, to 150 NM west of
Gambell as a 956 mb low by 3pm Sun, and to near Cape Lisburne as a
975 mb low by 3pm Mon.

&&

.DISCUSSION...
At 00Z, Models initialize well aloft. Models show similar
solutions aloft through Mon. With precipitation, models show
similar solutions with location and amounts of precip through 3pm
Sun. For Sun night and Mon the GFS/ECMF maintain similar areal
coverage and amounts, while the NAM starts to diverge. Favor the
consistency of the GFS/ECMF precip for Sat night and Sun.

At the surface at 06Z, models all verify well most features, but
the NAM and ECMF are 4-6 mb too weak on the high over the ALCAN
Border, while the GFS and Canadian verify well on that and other
features. All models show similar solutions on the incoming deep
Bering Sea Low through 3pm Sun. After that time models show
similar movement on surface low but the ECMF keeps that low deeper
longer than the NAM and GFS, while the GFS keep the high in the
Yukon stronger than other models. Favor the GFS, but will bump up
winds 3-5 kt Sun night and Mon over the North Slope and NW AK to
account for the GFS weakening the surface low too quickly.

Bottom line for models, is that we will use a blend of the
GFS/NAM/ECMF through 3pm Sun for precip, temps clouds, then use a
blend of the GFS and ECMF for Sun night and Mon for precip/ temps/
clouds. For surface field and winds, will use a blend of the GFS
and Canadian through 3pm Sun, then use the GFS winds for Sun
night and Mon while bumping up winds speeds 3-5 kt over NW AK and
the North Slope.

Coastal Hazard Potential Days 3 and 4...
The strong south winds over the Bering Sea today and tonight, will
become southwest on Sun and remain southwest into Mon. This will
cause sharp rises in sea levels along the West Coast of Alaska
from the Bering Strait south starting early Sunday, and will
bring the possibility of coastal flooding. Sea levels could rise
4 to 6 feet above normal along the West Coast from the Bering
Strait south, which could flood low lying areas along the coast
and cause ice to pile up on the beach. Although there is extensive
sea ice in this area, the ice is highly fractured and will likely
only partially dampen the storm surge, and could pile up on the
beach. People along the coast from the Being Strait south should
move boats and valuables away from the shore to prevent damage
from sea ice and minor flooding. This should be done today, before
the next blizzard hits.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Blizzard Warning for AKZ207-AKZ208-AKZ209-AKZ210-AKZ211-AKZ212-
AKZ213-AKZ214.

Winter Storm Watch for AKZ218-AKZ219.

Wind Chill Advisory for AKZ223-AKZ224-AKZ225-AKZ226.

Coastal Flood Watch for AKZ211-AKZ212-AKZ213-AKZ214.

Winter Weather Advisory for AKZ206-AKZ221-AKZ227.

Winter Storm Warning for AKZ215-AKZ216-AKZ217.

Heavy Freezing Spray Warning for PKZ210.

Gale Warning for PKZ215-PKZ220-PKZ225-PKZ230.

Storm Warning for PKZ200-PKZ210.
&&

JB DEC 21