Area Forecast Discussion
Issued by NWS Fairbanks, AK

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000
FXAK69 PAFG 262309
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
209 PM AKST Sun Feb 26 2017

.DISCUSSION...
Blizzard conditions still ongoing across parts of the Arctic
Coast with visibility less than one half mile in blowing snow
inland over the coastal plain. Snow is ongoing over the Kobuk and
Noatak Valleys. Once this latest winter storm winds down, our
attention and focus will turn the dramatic change to below normal
temperatures advertised by the deterministic models mid to late
this week and into next weekend. The 26/12Z deterministic model
suite is in good agreement through late this week with model
solutions diverging into next weekend, especially with the
progression of an upper level low and the coldest air at H850 over
eastern Alaska.

Aloft...A strong shortwave over the northern Bering Sea will dig
southeast over southwest Alaska tonight into Monday as an upper
level ridge rapidly builds north over the western Bering Sea.
Several weak shortwaves will move south over the Interior Alaska
as the stronger shortwave digs southward Monday night into Tuesday.
An omega block with the ridge axis centered over the Bering Sea
and eastern Siberia will persist throughout this week. Downstream,
the aforementioned strong shortwave will become a closed off upper
low by Tuesday morning over the eastern Gulf of Alaska with
a secondary upper low center forming Wednesday, which will remain over
the Gulf of Alaska through Thursday. A very cold 475 dam upper low
over the Canadian Arctic Archipelago will gradually push
southward, bringing with it very cold H850 temperatures for late
in the forecast period.

Strong cold air advection at H850 will commence following the
passage of the aforementioned strong shortwave. The Alaska West
Coast and Western Interior will see H850 temperatures plummet 10C
to 15C by 00Z Tuesday. This cold airmass will spread east over the
rest of Northern Alaska Tuesday and Wednesday with H850
temperatures between -20C to -25C. Models are hinting at the
possibility that -30C or colder H850 temperatures over the North
Slope and Eastern Interior late this weekend into next week. Will
have to continue to monitor.

Surface...Surface high pressure stretching from the northern
Pacific, north over the Bering Sea and Eastern Siberia, and into
the high Arctic will continue to build and expand east over
mainland Alaska through Wednesday, building to 1051 mb. Low
pressure centered over the eastern Gulf of Alaska will develop
Monday night and persist there through mid week.

Arctic Coast and Brooks Range...Blizzard conditions persist along
the majority of the Arctic Coast where Blizzard Warnings are
ongoing. Inland over the coastal plains, conditions are better as
winds are not as strong, but visibility are still restricted under
one half mile in blowing and drifting snow. Will keep the blizzard
warnings and winter weather advisories going as is with the
expectation that conditions will gradually improve into the
evening. Skies will begin to clear tonight and temperatures will
take a 10 to 20 degree downward turn towards normal values, then
colder than normal temperatures late next weekend into early next
week.

Western Interior and West Coast...The last two remaining winter
storm warnings over the Kobuk and Noatak Valleys have been
extended through 6 pm this evening. Elsewhere, isolated to
scattered snow showers to continue through Monday afternoon and
will diminish as the ridge of high pressure builds overhead.
Expecting snow to taper off and for conditions to improve.
Temperatures will plummet 15 to 20 degrees across the region from
what they recently through tomorrow and will remain below normal
through late this week.

Eastern and Central Interior...Scattered to numerous snow showers
will persist across the region through Tuesday morning and could
see a couple more inches of snow collectively. Will see a gradual
cooling trend over the next few days, then a more dramatic cool
down to below normal temperatures as skies clear. Interior valley
locations could possibly see overnight lows 25 below to 35 below
by Thursday morning. Models do hint at colder temperatures heading
into next weekend, but will have to continue to monitor feature
model runs to see how this plays out.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Winter Storm Warning for AKZ208-AKZ217.

Blizzard Warning for AKZ201-AKZ202-AKZ203-AKZ204.

Winter Weather Advisory for AKZ205-AKZ206.

Gale Warning for PKZ230.

Brisk Wind Advisory for PKZ200-PKZ210-PKZ220-PKZ235-PKZ240-
PKZ245.
&&

$$

LTH FEB 17



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