Gale Warning 46, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
320 PM AKDT Sat Apr 4 2020

.SYNOPSIS...
The active weather pattern over Northern continues through early
next week, as a series of weather systems move across the area.
Across the West Coast and Western Interior, heavy snowfall,
especially in the favored upslope areas, is expected, with rain or
freezing rain mixing in with the snow from Kotzebue south. Strong
and gusty winds, are expected to develop on the back side of the
low tonight and into Sunday causing blowing snow. Across the
Central and Eastern Interior, widespread snowfall is continues
with rain expected to mix in with the snow across the Southern
Interior. Winds increase across the Interior by Sunday, causing
blowing snow over summits. A coastal surge will impact the West
Coast with the possibility of water moving overtop the ice and
then inland during the weekend.

&&

.DISCUSSION...
Models...
The 12Z model suite initialized well against the 12Z surface
analysis and verified well against the 18z surface analysis.
Models continue to struggle with the evolution, track and strength
of a strong low in the north Bering Sea and subsequent triple
point that develops over the Seward Peninsula and mover over the
Central Interior and Brooks Range. Significant differences emerge
in the model solutions on the strength and track of the triple
point low as early as tomorrow afternoon. The GFS remains the
outlier as it moves the upper low across northern Alaska,
maintaining more energy. We continued to lean towards the NAM for
winds, with local edits to increase winds across the Y-K Delta and
across the Interior. Blended in the SREF for pops to capture
higher values.

Aloft at 500 mb, a high pressure ridge over Central and Eastern
Alaska will merge with a 555 dam high pressure ridge centered just
east of Banks Island as a 496 dam low centered near the pole with
a deep longwave trough extending south through the Bering Strait
and Central Bering Sea will continue to deepen and push slowly
east into the Eastern Bering and over the West Coast of Alsaka
through early next week. A strong shortwave troughs will move
north and east through the longwave and will push a 504 dam low
east over the Brooks Range with a trailing strong shortwave south
of the low pushing over the West Coast and Western Interior on
Sunday and over the Central and Eastern Interior on Tuesday. Much
colder air aloft will push eastward over Alaska with the 850 mb
temperature over Fairbanks dropping from around 4 below this
evening to 7 below Sunday morning and near 20 below by Monday
morning. Strong and gusty winds at the surface will accompany the
cold air aloft and will produce blowing and drifting snow over
much of the West Coast and Interior especially the highway Summits
in the Interior.

Surface...A 985 mb low currently 250 nm southwest of the Bering
Strait will continue to push north and east to be over the Bering
Strait Sunday morning and along the Northwest Coast and Western
North Slope on Sunday morning. The low will deepen again as it
taps some cold air as it pushes just south of Point Barrow
tomorrow evening. As the low continues to push east expect strong
winds and falling snow to produce reduced visibilities in blowing
snow to the East of Prudhoe Bay. A Winter Weather Advisory for
blowing snow has been issued for zone 204 beginning at midnight
tonight. A triple point low develops over the Western Seward
Peninsula this evening and will and will push east into the
Eastern Seward Peninsula Sunday and the Western Interior Monday
Morning. The low will continue to weaken into a trough over the
Central Brooks Range Monday afternoon and will continue to move
north east over the the Eastern Brooks Range Monday night.

North Slope and Brooks Range: A series of weather systems moving
across the region will bring more snow through the weekend. The
heaviest snowfall will occur on the southern facing slopes of the
Brooks Range. From Utqiagvik west, 3 to 5 inches of snow are
possible through weekend. East of Utqiagvik snowfall totals will
generally be less than an inch. Gusty south winds continue in the
passes of the eastern Brooks Range tonight, with gusts to 40 mph
possible. Maintained the Winter Weather Advisory for zone 206 for
blowing snow in the passes of the eastern Brooks Range and added a
Winter Weather Advisory for zone 204 where strong westerly winds
gusting to 55 mph wrapping around a deepening low north of the
Eastern Arctic Coast will produce reduced visibiltiy in blowing
snow east of Prudhoe Bay.

West Coast and Western Interior: The latest in a series of weather
fronts is moving north and east across the West Coast and Western
Interior this afternoon, bringing a mix of rain and snow to the
region. A strong low will move over St Lawrence Island this
evening to Kotzebue Sound by Sunday and then weaken Sunday night.
This system will produce heavy snowfall, especially in the favored
upslope areas, strong winds, and blowing snow. Rain or freezing
rain may mix in with snow at times this evening, primarily from
Kotzebue south, before precip transitions to all snow by late
tonight. Strong winds will develop tonight and Sunday on the back
side of the low, with gusts to near 60 mph possible across the Y-K
Delta and Norton Sound. This will cause areas of blowing snow
likely reducing visibility to less than half a mile at times.

Central and Eastern Interior: A weather front moving in from the
west continues to bring widespread snowfall to the Interior
this afternoon and will continue into Monday. The heaviest
snowfall is expected to occur from Tanana north. The Middle Tanana
Valley could see an additional 1 to 3 inches of snow tonight and
an additional 1 to 2 inches on Sunday, with the highest amounts in
the hills north of Fairbanks. Rain may mix with snow at times
across the southern Interior and could result in lower snowfall
totals. Southwest winds increase late tonight and will continue
into Monday, with gusts to 30 mph. This will result in blowing and
drifting snow, especially across the summits of the Interior. In
the passes of the Alaska Range, southerly gap winds continue to
increase this evening, peaking overnight with gusts to 50 mph in
the western Alaska Range passes and 45 mph in the eastern Alaska
Range passes. The winds are expected to diminish Sunday morning an
are expected to remain below wind advisory criteria.

Coastal Hazard Potential...The ongoing strong weather system that
is currently affecting the west coast will continue through this
weekend. This storm has the potential to cause elevated water
levels along the coast. As water levels rise there is the
potential to push water on top of the ice through open leads and
along the coast where shorefast ice is breaking up. Areas around
Norton Sound and along the Yukon Delta will be most susceptible as
the low moves inland.

&&

.FIRE WEATHER...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Coastal Flood Advisory for AKZ211-AKZ212.

Winter Storm Warning for AKZ207-AKZ208-AKZ209-AKZ210-AKZ211-
AKZ213-AKZ217-AKZ218-AKZ219.

Winter Weather Advisory for AKZ204-AKZ206-AKZ212-AKZ214-AKZ215-
AKZ216-AKZ220-AKZ221-AKZ222.

Gale Warning for PKZ200-PKZ210-PKZ220-PKZ225.

Brisk Wind Advisory for PKZ215-PKZ230-PKZ235-PKZ240.
&&

CCC APR 20