Gale Warning 120, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
418 PM AKST Fri Dec 28 2018

.DISCUSSION...
Active weather pattern setting up for the weekend with a series of
shortwaves moving across northern Alaska. Wind will be the primary
concern. Strong winds will bring periods of blowing snow reducing
visibility to the West Coast Sunday. Strong chinook winds expected
to develop across the Alaska Range Sunday and Monday with southerly
winds of 50 to 60 mph with gusts to 80 mph.

Aloft, at 500 mb, a trough axis extends south across the Chukchi
Sea and the Bering Sea with a closed low over the northern
Chukotsk Peninsula. A low is centered between St Lawrence Island
and Nome, with a shortwave extending south to Hooper Bay to
Goodnews Bay to Ivanof Bay. Ridging extends north from the western
Pacific and across the Central and Eastern Interior. A developing
low is southwest of the Aleutians. The low between Nome and St
Lawrence Island this afternoon will weaken and become absorbed by
the shortwave lifting northeast across the state. The shortwave
will extend from Shishmaref to Stebbins to Crooked Creek to Kodiak
by early Saturday morning and continue lifting northeast to be
along a line from Point Hope to Kotzebue to Tanana to Anderson
Saturday afternoon and be situated along the Arctic Coast by
Sunday morning and offshore by Sunday afternoon. As this shortwave
moves north, the low and trough axis over the Chukchi Sea will
elongate and stretch across the Beaufort Sea to the Gulf of
Anadyr by Sunday. The low southwest of the Aleutians will life
north tonight and Saturday to be near Shemya before weakening and
moving south Sunday into Monday. Another shortwave will begin to
move north across the state Sunday.

Surface...A 1007 mb low is centered 150 NM northeast of Kaktovik.
A trough extends from Point Hope to Noatak to Huslia to McGrath
and south to a 996 mb low centered near King Salmon. A 1016 mb
high is centered northeast of Dawson. A 968 mb low is centered 300
NM southwest of Shemya. The low northeast of Kaktovik will lift
northeast tonight with a trough developing north of the Brooks
Range. A 1005 mb low will pinch off of this trough Saturday night
and move over the Arctic Coast to be located 100 NM northeast of
Utqiagvik by Sunday morning and deepening to 997 mb by Sunday
afternoon and be located 275 NM north of Nuiqsut. The trough
deepens north of the Brooks Range Sunday and Monday with the
pressure gradient tightening. The low south of Shemya this
afternoon will deepen tonight and be located just west of Kiska
Island Saturday morning before meandering to be southwest of Kiska
Island Sunday morning and near Adak Monday morning. A second low
will develop south of Nikolski Saturday afternoon, deepening and
moving north of Dutch Harbor Saturday night and into the Bering
Sea Sunday morning, continuing north through the day Sunday. This
will tighten the pressure gradient across the West Coast.

Models...12Z model runs initialized well against the 12Z surface
obs, with the NAM capturing the tighter pressure gradient across
the west coast and the low north of Barter Island well. Opted to
learn towards NAM guidance today for winds. Models are in good
agreement though Sunday before major differences begin to become
apparent. The GFS quickly spins up a strong low moving north
across the Aleutians and brings it north across the Pribilofs and
into the Bering Sea, while the NAM, ECMWF, and Canadian develop
much weaker lows further to the east.

North Slope and Brooks Range: A shortwave moving across the Brooks
range and North Slope Saturday into Sunday will bring snow to the
region, with snowfall accumulations of 1 to 2 inches, with the
highest amounts occuring in the western Brooks Range. Generally
light winds expected, with exception of around Cape Lisburne,
where north winds will average 15 to 20 mph with gusts to 30 mph.
Winds near Barter Island will diminish overnight as the low
offshore moves north. Pressure gradient tightens across the
eastern Brooks Range Sunday into Monday. Strong southerly winds
will develop across the eastern Brooks Range, especially in the
passes, with wind gusts to 40 mph possible late Sunday into early
Monday.

West Coast and Western Interior: Active weather pattern expected
across the region through the weekend. A weather front and
shortwave moving northeast across the West Coast and Western
Interior tonight and Saturday will bring periods of snowfall, with
snow tapering off from the west to the east during the day
Saturday. Snowfall totals will range from less than an inch from
west of Buckland and Kaltag to 3 to 4 inches from Huslia to Ambler
with the highest amounts east of Shungnak. Winter Weather
Advisories remain in effect through noon Saturday for zones 216
and zone 217, with additional snowfall amounts of 2 to 4 inches.

The next round of snow begins to move north across the Y-K Delta
Saturday night and further north and east during the day Sunday,
as a strong low moves across the Bering and a weather front moves
north across the region. Heavy snow will be possible with this
system. This low will tighten the pressure gradient along the
West Coast bringing north northeast winds of 20 to 30 mph with
gusts to 40 mph. Stronger winds are possible in the Y-K Delta,
eastern Norton Sound, and the Nulato Hills and will need to be
closely monitored. The strong winds may potentially result in
blizzard conditions. Northeast winds are expected to be stronger
on St Lawrence Island with gusts to near 60 mph. A Winter Storm
Warning has been issued for zone 213 for strong winds and reduced
visibility due to blowing snow for the ongoing blowing snow and
for the second round on Sunday. A strong chinook is expected to
develop across the Alaska Range Sunday, resulting in south winds
of 50 to 60 mph with gusts to 80 mph in the passes and foothills.
A High Wind Watch has been issued for zone 227. Warmer air behind
the front will push in bringing high temperatures into the 20F
above zero range Sunday and Monday.

Central and Eastern Interior: Shortwave and weather front moving
across the Interior will bring a round of snow tonight and
Saturday moving from the west and spreading eastward through the
day Saturday and tapering offing by Saturday night. Snowfall
totals of 1 to 3 inches are expected through Saturday. Wind is the
primary concern through Monday. A strong gradient is expected to
develop across the Alaska Range, with a strong chinook developing
Sunday and continuing into Monday. Issued a High Wind Watch for
zones 223, 225, and 226. Southerly winds of 50 to 60 mph with
gusts to 80 mph are possible in zones 225 and 226, especially
through the passes. Winds will be lower in zone 223, with winds of
40 to 50 mph possible primarily from Delta Junction south. Strong
southwesterly flow aloft will likely lead to increasing south to
southwest winds along the Alaska Highway from Tanacross towards
Dot Lake, with advisory level winds likely.

Another round of snow moves eastward across the Interior Sunday,
bringing snowfall totals of generally 1 to 3 inches for Sunday
through Monday and isolated higher amounts. Areas from Fairbanks
south and east will likely be shadowed out due to downsloping.
Warmer temperatures are expected by Monday, with much of the
Central and Eastern Interior 10 to 20 degrees above zero.

Coastal Hazard Potential Days 3 and 4...The sea ice extent will
result in no high water for the St Lawrence coast despite strong
winds and snow expected for Sunday.&&

.AFG WATCHES/WARNINGS/ADVISORIES...
High Wind Watch for AKZ223-AKZ225-AKZ226-AKZ227.

Winter Storm Warning for AKZ213.

Winter Weather Advisory for AKZ216-AKZ217.

Brisk Wind Advisory for PKZ210-PKZ220-PKZ225.
&&

EB DEC 18