Gale Warning 155, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
307 PM AKST Tue Dec 29 2020

.SYNOPSIS...
Snow and blowing snow with strong east winds are causing blizzard
conditions at Point Lay that will continue tonight, with strong
winds and blowing snow keeping reduced visibility near 1/2 mile
at Point Lay Wed through Fri.

A weather system moving north over the West Coast today and
tonight will bring 1-2 inches of snow to zones 211, 213, 214 and
215 today and tonight.

A weather system in the Western Gulf of Alaska will move north
over the Southern Interior on Wed and then dissipate through Thu
night. This will bring clouds and light snow or flurries over the
Southern Interior Wed into Thu night. This will cause east winds
to increase along the Tanana Valley tonight, and over the Summits
of the Interior from late tonight into Wed. This will cause some
blowing snow over Summits late tonight through Wed.

Near record low pressure will move north into the Western Bering
Sea Thu and persist into Fri, but will have little affect on
Northern Alaska.

Temperatures over Northern Alaska will remain well above normal
into Wed, then cool from Thu into the weekend, with below normal
temperatures by the weekend.

Aloft...
The long wave pattern consists of a deep trough over the Bering
Sea and the Western and Central North Pacific, and a ridge over
Western Canada and Northern Alaska, and another trough over
Eastern Canada. Several short wave trough will make their way
north over the West Coast and southern Interior of Alaska through
Thu bringing periods of light snow to the West Coast and
Southwest Interior, and flurries to the Eastern Interior.
A strong short wave with considerable cold air will move from the
Canadian Archipelago west towards Northern Alaska Fri into the
weekend. This will bring considerably colder air to Northern
Alaska this weekend.

A short wave trough that lies from the Chukotsk Peninsula to Point
Hope to Umiat will move northwest and weaken tonight. Snow along
this trough from near Point Lay will diminish late tonight as the
trough moves northwest.

A strong short wave in the Gulf of Alaska will move north over
the southern Interior on Wed, then persist into Thu before moving
east Thu night.

850 mb temperatures remain warm through Wed, with above freezing
SW of Nenana to Anvik through tonight. Temps then drop over NE
Alaska Thu, and drop significantly over all of Northern Alaska Fri
through Sun.

Surface...
An old occluded front that lies from Anadyr to Point Lay to Old
Crow will weaken in place through Thu. Flurries occuring along
this front and will linger in place through Thu. Snow occuring
near Point Lay will taper off to flurries early Wed as the
supporting trough aloft previously mentioned moves NW.

High pressure north of the Arctic Coast of Alaska will build
through Wed, then persist into the weekend. This, combined with
the occluded front is causing east widns gusting 40 mph from Point
Lay west that will continue through Fri. Point Lay has a blizzard
with near zero visibility now that will continue tonight with the
falling snow. As the falling snow ends Wed, visibility at POint
Lay will improve to 1/2 mile in blowing snow, and those conditions
will likely continue into Fri. The remainder of the Arctic Coast
has stratus and areas of fog with much less wind.

A 988 MB low near Nunivak Island will move to 100 NM southwest of
Gambell as a 992 MB low by 3am Wed, then move slowly west. This is
causing snow, rain and light freezing rain south of Anvik now that
will end this evening. The snow spread to zones 211 and 213 this
afternoon and continue into tonight. Expect 1-2 inches of snow
with this. Could see a light glaze of ice southwest of Anvik this
afternoon/evening.

A 1016 mb high near Dawson City will persist through Thu.
A 985 mb low just west of Kodiak will move to near Sparrevohn as
a 999 mb low by 3pm Wed, then slowly weaken in place through Thu.
An occluded front associated with this will move to along the
Alaska Range tonight, to Anvik to Ruby to Northway by 3pm Wed,
then weaken in place through Thu night. This will bring clouds and
light snow or flurries over the Southern Interior Wed into Thu
night. This will also combine with the high near Dawson to cause
east winds to increase along the Tanana Valley and Yukon near
Eagle tonight, and over the Summits of the Interior from late
tonight into Wed. This will cause some blowing snow over Summits
late tonight through Wed.

A 925 mb low will move into the southwest Bering Sea Thu, to the
Western Bering Sea on Thu, then weaken slowly through Sat. This
will bring easterly gale force winds and a chance of snow to St
Lawrence Island area on Thu night into Fri.

&&

.DISCUSSION...
At 12Z, models initialize well aloft. Models show similar large
scale pattern aloft with slight differences on short wave details
from Wed into Fri. All Models move a short wave over the Southwest
Interior on Wed, but the GFS linger this feature over the
southern Interior through Thu, while the NAM/ECMF and Canadian
models move this feature east more quickly.

With precipitation, models show similar solutions through 3pm
Wed, with slight differences Wed night through Fri. Still expect
clouds and a chance of light snow with the short wave moving north
over the southern Interior on Wed, with flurries lingering into
Thu night.

At the surface, models verify well at 18Z on most features, but
all area 2-3 mb too weak on the low southwest of Kodiak, and the
ECMF/NAM are about 4mb too weak on the high over the Dawson City
area while the GFS and Canadian verify well on this feature. The
GFS and Canadian models keep this high stronger than the NAM and
ECMF through Wed night. At this time favor the GFS at the surface
through Wed night, and will bump of winds several kt most areas,
but 3-5 kt in the SE Interior, to account for the slightly deeper
low moving in the SW Interior.

The ECMF deepens the low moving into the Bering on Thu more
quickly and deeper than the other models, but they all have it
near record low pressure. In terms of impacts on Northern Alaska,
there is little difference with this feature and will use a blend
of model winds for Thu into Fri.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning for AKZ201.

Small Craft Advisory for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ225-PKZ230.
&&

JB DEC 20