FXAK69 PAFG 190017

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
417 PM AKDT Mon Mar 18 2019

...Weather Highlights...
A storm over the Eastern North Slope is now causing strong winds
and blizzard conditions on the Eastern North Slope which will
abate at Deadhorse late this afternoon, and at Barter Island this
evening as winds decrease.

Snow developing along a cold front over the Central/Western
Interior tonight will spread to the Eastern North Slope Tue
bringing 2-4 inches of snow to those areas. The front will bring
a chance of rain and snow in the Eastern Interior Tue as well
along with a slight chance of freezing rain early Tue am.

A third storm will bring moderate to heavy snow to the Northern
and Western Interior and Eastern North SLope on Wed afternoon
through early Thu.

Moderate Chinook winds across the Alaska Range will taper off
early Tue, then redevelop on Wed AM.

A long wave trough persisting over the Bering Sea and across the
N Pacific to the Gulf of AK, with a long wave ridge over Western
Canada will persist through the weekend.

A short wave will make its wave NE across AK tonight and Tue, then
the ridge will build slightly from NW Canada over Northern AK Tue
causing southerly flow to weaken, before the next short wave
moves north over AK Wed night and Thu bringing more weather to the
Northern and Western Interior, and a return of southerly flow and
chinook winds.

End result for Nrn AK looks like continued windy and wet over
West Coast and Western Interior, much warmer than normal over the
Ern Interior, and near normal over the North Slope with periods of
winds and snow through the weekend.

A 990 mb low 100 NM north of Barter Island will move to 300 NM
northeast of Barter Island as a 996 MB low by 4am Tue, and then
move east. This is causing west winds 30g50 mph and blizzard
conditions at Barter Island, but the winds and blowing snow are
now diminishing at Deadhorse, and will rapidly diminish this
evening at Barter Island.

An Arctic cold front extending from this low to Old Crow to
Bettles to Telida will remain quasi-stationary tonight as a low
now located near Illiamna moves to Bettles as a 996 mb low by 4am
Tue. This low will push an occluded front aloft over the Arctic
front causing moderate snow to develop tonight over the Western
and Northern Interior. Expect 2-4 inches of snow from McGrath to
Atigun Pass from late tonight through Tue PM. This low will cause
south chinook winds along the Alaska Range to increase again
tonight then to decrease on Tue.

That low will move to MacKenzie Bay as a 993 mb low by 4pm Tue
with the cold front from there to Arctic Village to Delta Junction
by 4pm Tue. Snow will move east with the front giving Fairbanks
about 1 inch, but less chance SE of Fairbanks. There is a chance
of freezing rain in the warm air just east of the front Tue
morning, but it will be very brief and light. The low will cause
blowing snow Tue PM near Barter Island with reduced vsby.

That cold front moves to Inuvik to Eagle to Denali by 4 am Wed,
and then to Old Crow to McGrath by 4pm Wed, and to Barter Island
to Anaktuvuk Pass to the YK Delta by 4pm Thu. Cooler, though
still above normal temperatures will follow the cold front in the
Ern Interior.

A storm in the Gulf of Alaska will push its front north and merge
with the Arctic front late Wed giving a good overrunning snow
potential to the Northern and Western Interior for Wed afternoon
through Thu. Could See 4-8 inches of snow Wed PM through Thu,
with the heaviest amounts stretching from the Anvik to Atigun
Pass. This will also cause an increase in southerly chinook winds
again Wed into Thu, and cause the SE Interior to warm up again.

A 988 mb low 100 NM north of Wrangel Island will continue to move
north. A trough of low pressure extending south from this low
will move east to Point Hope and the Bering Strait by 4PM Tue, and
then continue east to Barter Island to the YK Delta 4pm Wed with the
trough merging with the Arctic front Wed night. SW winds 15-25 kt
will accompany this trough into NW AK Tue and Tue night, with the
winds turning N 15-25 kt West of the trough over the Brooks Range
Wed PM and Thu.

A 988 mb low 100 NM north of Wrangel Island will continue to move
north. A trough of low pressure extending south from this low into
the Western Bering Sea will move east to Point Hope and the
Bering Strait by 4PM Tue, and then move inland Tue night.


Models initialize well on most fields and show similar solutions
aloft. Models also show similar areal coverage for precip fields,
but differ some on amounts. For now we will go with a mix of GFS
and NAM precip amounts.

At the surface at 15Z, models all verify 4 mb too weak on surface
low just north of Deadhorse, and as a result winds are much
stronger than models indicate on eastern North Slope today. This
is curious since the NAM yesterday forecast the depth of the low
and the winds on the Eastern Arctic Coast for today quite well.
We have boosted the winds considerably to reflect reality on the
Eastern Arctic Coast for today, and the winds there should abate
quickly this evening as the surface low moves rapidly east.

Models show similar solutions at the surface through 12Z Tue,
then the NAM moves the surface low from the NE Interior to
Demarcation Point more quickly and at a lower depth than the GFS,
and gives much stronger winds at Barter Island Tue PM. This NAM
solutions seems better given the short wave supporting this
feature and the current deep depth of the feature. The NAM also
deepens a another surface low in MacKenzie Bay on Thu more than
the GFS, which again seems reasonable give the dynamics. For
these reasons we will use the NAM surface field for winds for
tonight through Thu.

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



Wind Advisory for AKZ223-AKZ226.

Blizzard Warning for AKZ204.

Winter Weather Advisory for AKZ203-AKZ206-AKZ218.

Gale Warning for PKZ240-PKZ245.

Brisk Wind Advisory for PKZ210-PKZ220-PKZ225-PKZ230-PKZ245.


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