780
FXAK69 PAFG 211056
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
156 AM AKST Tue Jan 21 2020

.Synopsis...Mostly cloudy skies and light snow or flurries will
continue today and into Wednesday as a second weak front pushes
east out of the Western Interior into the Central and Eastern
Interior. Warmer temperatures but still below normal temperatures
will continue through Wednesday before falling again toward the
end of the week and through the weekend. Winds will generally
be light and variable in the interior with the exceptions of the
Delta Junction area, and the Bering Strait Coast where east to
southeast winds to 25 mph will continue into Tuesday. No change
in the Arctic as a band of stratus will bring low clouds and
patchy fog to the Central Arctic Coast at times. As flow switches
back to northeast and east this afternoon expect stratus and fog
to move back in over the Eastern Arctic Coast.

.DISCUSSION...
Models continue to display excellent run to run continuity, even
into the extended periods with the 21/00Z solutions as they
develop an omega block pattern over the Eastern Bering Sea late
in the week. Surface solutions initialized well against 21/00Z
local analysis, but major features strength continues to
initialize high pressures systems too low and low pressure systems
too high. Highs in the Upper Tanana Valley and Upper Yukon Flats
continue to initialize about 5 mb high than the solutions, while
the lows to the west are about 3 mb weaker than the 21/00Z
solutions. This continues to under play winds along the Eastern
Arctic Slope and the Tanana Valley Jet and we have made local
edits to the wind fields to compensate. Clouds and local drainage
winds continue to play havoc with temperatures. We have made
local adjustments to computer guidance to the temperatures to
match with current temperatures and trends.

Aloft at 500 mb, the Omega Block that continues to develop with
its ridge axis over the Eastern Bering Sea and down wind low
pressure trough over Alaska. As the trough deepens a cold airmass
will be pushed south and west over Northern Alaska late this
week, over the weekend and into next week. This will prolong the
well below normal temperature trend of late well into next week.
The trough axis will remain north and west of Fairbanks which will
bring clouds and some moisture north and northwestward into
Central and Eastern Alaska and will prevent temperatures from
tanking as they would under clear skies. With 850 mb temperatures
in the 25 to 32 below range surface temperatures as still likely
to drop into the 20s, 30s and some 40s below in the coldest spots.
High temperatures are likely to remain in the teens and 20s below
beyond Friday of this week.

Surface...High pressure continues to dominate over Interior
Alaska with low pressure over the Gulf of Alaska and the West
Coast. High pressure will weaken allowing the decaying weather
fronts to move northeast across the state today and Wednesday.
1010 mb highs are in the Upper Tanana Valley and Upper Yukon
Flats and will slowly weaken through Wednesday. Leeside troughing
is redeveloping north of the Brooks Range and will form into a 999
mb low Wednesday as it moves north of Prudhoe Bay Wednesday. A
997 mb low over the northmen Gulf of Alaska will continue to
weaken and move on shore near Prince William Sound by Wednesday
morning.

Arctic Coast and Brooks Range...Some stratus, flurries, and
patchy dense fog along the Central coast will spread to the
Eastern Coast as a weak front continues to swing around the low
developing just north of the Brooks Range today. A front over the
Chukchi Sea will spread some flurries or light snow to the
Northwest Coast tonight.

West Coast and Western Interior...Decaying weather front
over the Western Interior will continue to spread flurries or
light snow across the Western and Central Interior today and
tonight with less than an inch of snow expected at most locations.
Winds generally light and variable inland and northeast to
southeast along the coast at 5 to 15 mph. Temperatures warmer
today, then cooling.

Central and Eastern Interior...Mostly cloudy with flurries or
very light snow expected today and tonight. Less than one inch of
snow is expected over most of the area. Winds generally light and
variable, the exception will be the Delta Junction area where
winds will be gusting to 15 to 25 mph today.

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

Extended forecast for days 4 to 7...Decreasing chances of
precipitation with more breaks in the clouds. Cold air digs back
south over the state with temperatures falling through the
weekend. A front moving around a low in the Gulf of Alaska will
move into the Southeast Interior Sunday spreading snow northwest
into the Tanana Valley east of Tanana.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

CCC JAN 20