Blizzard in Alaska, January 29 to 31, 2024

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
647 AM AKST Mon Jan 29 2024

.SYNOPSIS...
The cold Arctic airmass over Northern Alaska will persist through
the end of the week, and possibly into next weekend over the
Interior. A weather front moving north across the Eastern part of
Northern Alaska has brought light snow and moderating temperatures
the Central and Eastern Interior and Eastern North Slope this
morning that will spread northwest to McGrath and Point Lay by
this afternoon, and with snow and moderating temperatures
continuing over much of the area east of Point Lay to McGrath
tonight. Snow will linger over the North Slope Tue and Tue night,
while diminishing to a chance over the Interior on Tue. Most of
North Alaska will return to very cold temperatures on Wed and
remain there into the weekend.

Areas north of the Yukon River to the Brooks Range can expect
another 4 inches of snow through tonight, and Dalton Highway
Summits and Brooks Range passes will have northeast winds gusting
to 35 mph and low visibility in blowing snow through tonight.

North winds gusting to 40 mph through Alaska Range passes this
morning will taper off by noon and turn southerly in the
afternoon. The North side of the Alaska Range can expect another
several inches of snow this morning, While the south side of the
Alaska Range can expect another 4-8 inches of of snow today with
snow diminishing there tonight.

The North Slope can expect 4 to 6 inches of snow from this
afternoon Today into Tue night, with near blizzard conditions and
east winds gusting to 35 mph this afternoon tonight. The Eastern
Arctic Coast can expect blizzard conditions with east winds
gusting to 45 mph through this evening, with snow continuing into
Tue and a possible return of blizzard conditions Tue night.

North winds of 15 to 25 mph along the West Coast west of Kivalina,
Nome and St Michael are causing very cold wind chills that will
continue into tonight.

West Coast will remain mainly clear and cold through late this
week and possibly warm over the weekend.

Surface...
A low pressure trough from Point Hope to the Yukon Delta will
persist through 3am Tue and then weaken. This will cause north
winds increasing to 15 to 25 mph along much of the West Coast
today and persisting into tonight before decreasing on Tue.

An occluded front aloft from Denali to Arctic Village will move
northwest to MCGrath to Barter Island 3pm Mon, then along the
Arctic Coast of Alaska by 3am Tue and just north of the Arctic
Coast by 3pm Tue. Snow and increasing northeast winds will spread
north ahead of this front with winds decreasing south of the
front. A 988 mb low developing 30 NM south of Barter Island by 3pm
Mon will move to Demarcation Point as a 982 mb low by 3am Tue, to
near Inuvik as a 996 mb low by 3pm Tue, then move east. This will
cause winds to gust to 45 mph near Kaktovik this afternoon into
tonight. Winds will turn along the Arctic Coast SW south of the
front on Tue and increase over the Eastern Arctic Coast Tue night.

A 988 mb low developing 60 NM west of Point Lay by 3am Tue, will
move to near Wrangel Is as a 1000 mb low by 3am Wed. A low in the
northwest Bering Sea will deepen and move to the southeast Bering
Sea by 3pm Tue.

A very deep low in he Gulf of AK will move to near Dawson as a 983
mb low by 3am Tue and then weaken. An occluded front this is
feature will move north to Denali to Old Crow by 3pm Mon, to
Denali to Barter Is by 3am Tue and then dissipating. Another band
of snow will move north with this front. This will cause N winds
in the AK range to turn south Mon PM as the front moves north, and
cause N winds in the Brooks Range to turn south Tue.

A low in the northwest Bering Sea will deepen and develop into a
polar low and move to the southeast Bering Sea by 3pm Tue.

High pressure developing over Interior AK Tue will build through
the week. This will cause clearing over much of Northern AK Tue
night into Wed, with temps falling back to very cold cold
conditions, and remaining very cold through the end of the week.

A storm approaching SW AK this weekend could cause warming there.

&&

.DISCUSSION...
Models initialize well aloft at 00Z and show similar solutions
aloft through 3am Wed. After that time, the NAM deviates from
other models which develop a deep low aloft over Northern AK on
Wed. Favor a blend of models for solutions aloft through 3am Wed,
then a blend of the GFS and ECMWF for features aloft for Wed PM
into the end of the week.

The long wave pattern consists of a deep trough over the Bering
Sea and Western AK and a strong ridge over the Western CONUS and
Western Canada. This pattern will persist into Tue and allow a
series of strong short wave troughs to push from the Gulf of
Alaska northwest over the Interior and North Slope through Tue.
The long wave will retrograde Wed but eject a large amount of
energy and cold air east across AK on Wed forming a deep low aloft
over Northern AK on Wed that will remain over the Eastern Interior
into the weekend. A ridge will build north over the Eastern
Bering on Wed, then build over eastern Bering and West Coast of AK
Thu into Fri, with this ridge possibly weaken over the weekend.

What this all means is that the West Coast will remain mainly
clear and cold through late this week and possible warm over the
weekend. It also means that snow will spread northwest across the
Interior and North Slope today and tonight and linger into Tue.

A short wave that extend front McGrath to Barter Island will move
to McGrath to Point Lay then weaken into Tue. Clouds and light
snow are spread NW with this feature.

A second short wave over the SE Interior will move to Denali to
Old Crow this afternoon, to Denali to Barter Island by 3am Tue,
then move along the Arctic Coast on Tue PM and weaken Tue night
then move offshore on Wed. This will spread another band of more
significant snow northwest today and tonight that will linger
into Tue night along and north of the trough.

850 mb temperatures of -24C to -32C over Northern AK this morning
will warm to -10C to -20C over the Eastern Interior and Eastern
North Slope today and tonight. The the very cold Arctic air will
push back east over those areas Tue PM and Wed and remain into the
end of the week. Southwest AK could see warming this weekend.
With these temps, snow to liquid ratios will generally be 10 to
1, except in the Eastern Interior where ratios will rise to 20 to
1 south and east of Fairbanks today and tonight.

With precipitation, models have similar patterns through Tue, with
more differences showing up Tue night and Wed. Since the NAM is
the outlier Tue night and Wed will not us e the NAM precip Tue
night or Wed. Will use a blend of models for precip through Tue,
then a blend of the GFS, ECMWF for Tue night and Wed. Highlights
are:
Light snow over the Central and Eastern Interior and Far Eastern
North Slope spreading northwest to McGrath and Point Lay by this
afternoon, then continuing much of the areas east of Point Lay to
McGrath tonight then lingering over the North Slope Tue and Tue
night while diminishing to a chance over the Interior Tue with
little if any snow south of the Brooks Range Tue night and Wed.
Expect several inches of snow across the Interior through tonight,
with another 4 inches near the Brooks Range and AK Range. Expect
another 4-8 inches along the South Slopes of the Alaska Range
today with snow diminishing there tonight. The North Slope can
expect 2-4 inches of snow through tonight, with another 2-4 inches
Tue and Tue night.

At the surface at 06Z, models verify well on most features, but
all appear to be too weak on the low in the southern Gulf of AK.
The NAM bring this low north to the Gulf of AK Coast today deeper
than other models, and then fairly similar to the ECMWF tonight
into Tue. The NAM and ECMWF are similar at the surface on most
features tonight through Tue. Tue night and Wed NAM and ECMWF
differ on the depth of the low over the Chukchi Sea and the low
over the SE Bering. At this time favor the ECMWF on those
features. Will use the NAM for surface with details through Tue
afternoon. For Tue night and Wed sine the NAM is the outlier
aloft, will use the ECMWF and Canadian for winds.
Highlight are:
North winds increasing to 15 to 25 mph along much of the West
Coast today and persisting into tonight before decreasing on Tue.
Northeast winds 15 to 25 mph over the Brooks Range and Dalton
Highway Summits will decrease this evening. North winds gusting to
40 mph through Alaska Range passes this morning will taper off by
noon and turn southerly in the afternoon. East winds increasing to
25 mph along the Arctic Coast from Utqiagvik east today with 35
mph near Barter Island. Those winds will continue into tonight
then decrease Tue AM. West winds 20 to 30 mph developing over the
Eastern Arctic Coast Tue night and continuing into Wed.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
AK...Wind Chill Warning for AKZ801.
     Winter Weather Advisory for AKZ812-831-832-834-842.
     Wind Chill Advisory for AKZ814-815-820>822.
     Winter Weather Advisory for AKZ803.
     Wind Chill Advisory for AKZ825-826.
     Winter Weather Advisory for AKZ804.
     Winter Storm Warning for AKZ805.
     Winter Weather Advisory for AKZ848.
     Winter Weather Advisory for AKZ849.
     Winter Weather Advisory for AKZ850.
     Winter Weather Advisory for AKZ809.
PK...Brisk Wind Advisory for PKZ806-807-854-856.
     Brisk Wind Advisory for PKZ810-811-857.
     Brisk Wind Advisory for PKZ812.
     Brisk Wind Advisory for PKZ813-859.
     Gale Warning for PKZ814.
     Gale Warning for PKZ815-861.
     Brisk Wind Advisory for PKZ858.
     Gale Warning for PKZ860.
&&

JB