Coastal Flood in Alaska, November 4 to 6, 2020

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
308 PM AKST Tue Nov 3 2020

.SYNOPSIS...
Active weather continues for Northern Alaska with consecutive
storms aiming for the West Coast. The first storm continues this
evening and will diminish by Wednesday morning. The second and
much stronger storm in a series of storms is taking aim at the
West Coast Wednesday night into Friday with the potential for
prolonged storm surge and coastal flooding, heavy snow, and
blowing snow as well as local blizzard conditions. This storm will
bring heavy snow and blowing snow to the Western Interior
Thursday and Friday. The heavy snow will continue to push east
into the Central and Eastern Interior late Thursday and Friday for
the Central Interior and Friday in the Eastern Interior. The
clouds and snow will help break the Interior out of the arctic
grip with well below temperatures moderating to near normal by the
end of the week.

&&

.DISCUSSION...
Aloft at 500 mb a deep and cold trough continues over eastern
Alaska, the Northeast Gulf of Alaska and the Yukon as a ridge
builds east Western Alaska. A shortwave on over the Bering Strait
continues to dive south into the Gulf of Alaska tonight and
Wednesday and is eventually merges with the upper level trough
over the Northeast Gulf of Alaksa. This ridge over the Eastern
Bering Sea pushes east over the West Coast and Western Interior
Wednesday as a strong upper level low over the Western Bering
pushes east over the Central Bering Wednesday and Thursday.

Central and Eastern Interior...
The arctic airmass is beginning to modify as temperatures aloft
slowly warm. Temperatures will be a few degrees warmer on
Wednesday and will rise dramatically on Thursday and Friday as
clouds and snow move into the area and the upper level trough
pushes to the east. A strong storm in the Bering Sea will push
deep moisture into the Interior forcing the moisture to rise up
over a deep arctic airmass on Thursday and Friday. This will set
up the potential for significant snow event over the central and
eastern Interior beginning late Thursday and continuing into
Saturday. Strong gap winds will develop through the Alaska Range
passes on Thursday night into Friday as a strong pressure gradient
develops across the Alaska Range.

North Slope and Brooks Range...
Light snow and winds of 15 to 25 mph continue tonight and tomorrow
as a weak front rotating around a low pressure system north of
the coast pushes east over the North Slope tonight. Winds will
remain mostly out of the southwest the next couple of days with
light snow continuing as a series of weak fronts enter the region
from west to east.

West Coast and Western Interior...
A very strong storm will move into the Western Bering Sea on
Wednesday, then along the West Coast of Alaska on Wednesday night
and then move east into the Interior of Friday.

This storm is expected to bring heavy snow, blizzard conditions,
and southerly gales to St Lawrence Island on Wednesday, and to the
remainder of the West Coast of Alaska Wednesday night through
Friday. Snow will mix with rain Thursday and Friday in some
coastal areas mainly south of the Bering Strait.

Coastal flooding is possible along the coast from the Bering
Strait south to the Yukon Delta from Thursday through Friday,
with sea levels there rising 4 to 8 feet above normal.

Coastal Flooding is possible along the Coast from the Bering
Strait to Point Hope from Thursday night through Friday, with sea
levels there rising 3 to 6 feet above normal.

This storm is expected to bring heavy snow, local blizzard
conditions, and and strong southeast winds to the West Coast
beginning late Wednesday night and will continue into Friday.
Rain may mix with snow along the coast to the south of the Bering
Strait.

A storm currently impacting the West Coast of Alaska this evening
with snow and blowing snow as well as high surf will diminish
later tonight. Conditions will quickly deteriorate again Wednesday
evening as the next storm approaches.

Coastal Hazard Potential Days 3 and 4...
Coastal flooding is possible along the coast from the Bering
Strait south to the Yukon Delta from Thursday through Friday,
with sea levels there rising 4 to 8 feet above normal.

Coastal Flooding is possible along the Coast from the Bering
Strait to Point Hope from Thursday night through Friday, with sea
levels there rising 3 to 6 feet above normal.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
High Surf Advisory for AKZ207-AKZ213-AKZ214.

Winter Weather Advisory for AKZ207-AKZ213-AKZ214.

Heavy Freezing Spray Warning for PKZ200-PKZ215-PKZ220-PKZ225-
PKZ230-PKZ235.

Small Craft Advisory for PKZ220-PKZ225-PKZ230-PKZ235.

Gale Warning for PKZ200-PKZ210.

Brisk Wind Advisory for PKZ240-PKZ245.
&&

CCC NOV 20