Winter Storm Warning 5, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
500 PM AKST Tue Feb 22 2022

SYNOPSIS...
Northern Alaska now heading into very warm and wet pattern that
will persist into the weekend.

A strong storm in the Chukchi Sea is causing snow and blowing
snow issues over NW Alaska and the Brooks Range that will spread
east across the Arctic Coast today and tonight. The snow and
blowing snow will diminish over NW AK this evening as the low
moves northeast, but will linger over the Eastern Arctic into Wed.

Snow over the Eastern Interior will taper off from the west
tonight, with another 1-2 inches southeast of Fairbanks.

Areas of light freezing rain or drizzle over the West Coast from
Nome south will continue into this evening.

Strong west winds and blowing snow over Steese Highway summits
will continue into this evening and then diminish after midnight.

A weather system moving north over the West Coast on Wed will
bring snow and blowing snow that will transition to snow and
freezing rain and then to rain as far north as Nome on Wed, and
then as far north as Cape Lisburne on Thu. Will issue Winter
Weather Advisories for these events.

Winds will increase through Alaska Range Passes Thu into Fri.

Aloft...
The long wave pattern consists of a strong ridge over the Eastern
Pacific and Western N America with a deep trough over the Bering
and NW Pacific.

A strong short wave now over Western North Slope and Central
Interior will move east of the ALCAN Border tonight. Snow is
occuring along and east of this trough over the North Slope and
Eastern Interior, with snow tapering off west of the trough and
some breaks in the clouds. Expect another 1 inch or so of snow
tonight. Strong West winds and blowing snow over Steese Highway
Summits accompany this trough now, and the winds will decrease
late tonight as the trough moves east.

A series of short wave troughs will continue to move north over
Alaska in this pattern through next weekend. This will cause
Northern Alaska to be much warmer and wetter than normal through
the weekend, with the Eastern Interior will have periods of drier
chinook conditions.

Surface...
A 988 mb low 200 NM northwest of Utqiagvik will move to 300 NM
north of Barter Island as a 987 mb low by 3am Wed, then move east.
A cold front stretching from this low to the Bering Strait will
move to Barter Island to the Bering Strait by 3am Wed, then move
east and weaken Wed. West winds gusting to 40 mph and snow and
blowing snow with low visibility will spread east across the
North Slope with this front tonight, with conditions improving
West of Utqiagvik lat tonight, and then improving from Utqiagvik
east during the day Wed.

A strong low in the southern Bering Sea will move west tonight
and Wed. A second strong low will develop in the southern Bering
Sea Wed and move to the Western Bering Sea by Thu. This feature
will pus a warm front north over Bristol Bay tonight, over Norton
Sound on Wed, over the Seward Pen Wed night, and to Cape Lisburne
to Kaltag on Thu. This will bring snow and blowing snow just ahead
of the front that will transition to snow and freezing rain along
the front, and then to rain and snow south of the front.

High pressure will build over the Yukon Territory and Copper
River Basin tonight through Thu and Cause south winds 15-30 mph
through Alaska Range Passes. Strong winds are possible Thu night
and Fri as flow aloft becomes more southerly.

&&

.DISCUSSION...
At 12Z, models initialize well aloft and show similar solutions
aloft through Fri. Weak downslope conditions over the Alaska Range
on Wed night and Thu will become stronger on Fri.

850 mb temperatures will rise above 0C over SW AK tonight,
spreading to Fairbanks to the Bering Strait by 3pm Wed, to Fort
Yukon to Point Lay to by 3pm Thu, and to Old Crow to Deadhorse by
3pm Fri. ANy precipitation that falls will be a mixed snow and
freezing rain along this line changing to rain and snow south of
this line. There will also be mixed precip over SW Alaska into
this evening.

With precipitation models in fair agreement through 3pm Wed.
After that time, models differ some in areal coverage but
significantly in amounts. Since there are no good reasons looking
at other fields to account for all the differences, will handle
this for now by using a blend of models for precip location and
amounts.

At the surface at 18Z, models verify well on most features but the
Canadian model verifies best on the low over the Northern Chukchi
Sea and the winds over NW Alaska. Other models are a few mb weaker
and a bit further northeast with this feature. The Canadian model
keeps this feature a bit slower and deeper than other models
through 3pm Wed. After that time models in fair agreement on
surface pattern through Fri. Since winds over NW AK and the
Brooks Range are stronger than any models show by 5 kt or so, we
will use Canadian winds through Wed, but bump up winds 5 kt from
the Brooks Range north through midnight tonight to account for the
stronger verifying winds. For Wed night through Fri will use blend
of model for surface features and winds.

Bottom line for models is we will use a blend of models for temps,
precip location and amounts, and clouds. Will use the Canadian
model for winds through Wed but bump up winds 5 kt Brooks range
North this evening. Will use blend of models for winds Wed night
through Fri.

Coastal Hazard Potential Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning for AKZ225.

Winter Weather Advisory for AKZ201-AKZ202-AKZ203-AKZ204-AKZ206-
AKZ208-AKZ211-AKZ213-AKZ214-AKZ215-AKZ220-AKZ222.

Gale Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ220-PKZ225-PKZ230-PKZ235-
PKZ240-PKZ245.
&&

JB FEB 22