Area Forecast Discussion
Issued by NWS Fairbanks, AK

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FXAK69 PAFG 241336
AFDAFG

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
436 AM AKST Fri Nov 24 2017

.DISCUSSION...

Models...Run to run has been good the last few cycles for the
short term, but there continue to be widely ranging solutions in
the extended periods beyond 120 hours. The best approach today
will be the same as yesterday, so will primarily make only minor
changes by nudging the current forecast database with an equal
blend of the solutions for the short term. Of course the
temperatures will be extremely difficult to forecast as any place
that clears out will be much cooler than the forecast temperatures
coming out of the guidance, or vice versa, cloudy areas will be
much warmer than the solutions. The 24/00Z solutions once again
initialize well against the 23/06Z surface analysis for positions
and central pressures with very minor discrepancies.

Aloft...at 500 hpa...A 509 dam low is over Arctic Village and
will move south and merge with a low south of the Gulf of Alaska.
A 508 dam low over Barter Island will remain stationary into the
evening, then move south over Fairbanks at 516 dam by Saturday
afternoon, then moves southeast over Northway by Sunday morning
becoming stationary in a leeside trough north of the Alaska Range.
A 547 dam high north of the Canadian Archipelago will move
southwest to 500 nm north of Banks Island by Sunday morning with
ridging extending south over 140W to MacKenzie Bay, and southwest
to Point Hope. The ridge will move west to be over 160W by Monday
morning with ridging over most of the Arctic and extending
southwest over the Chukchi Sea and Gulf of Anadyr. Ridging over
the central Bering Sea over the Dateline today will move east to
the Bering Strait this evening with 540 dam heights extending
north over St Lawrence Island. This ridge will continue to move
east, but pulls south as it moves over the Western Interior
Saturday night, and will be over the Gulf of Alaska by Sunday
morning with only weak ridging extending northwest to the Seward
Peninsula. A 508 dam low will develop over the Central Aleutians
Saturday afternoon and move near Dutch Harbor by Sunday morning,
and over Bristol Bay by Monday morning. At 850 hpa...Some warmer
air moving over the southwest mainland on Monday, otherwise
temperatures over the forecast area -12C to -22C, coldest over the
southeast interior.

Surface...1003 mb low near Deadhorse will move east and merge
with low pressure over the Canadian Archipelago tonight. A 1023 mb
high north of the Canadian Archipelago will move southwest to 800
nm north of Point Barrow by Saturday morning with high pressure
extending south over the Central and Eastern Interior to a 1025 mb
high over Fort Yukon, then southeast to a 1024 mb high near
Dawson YT, and southwest to a 1023 mb high near Togiak. The high
will persist in the same area with the high pressure extending
over Togiak pulling back over the interior as a weather front
associated with a 987 mb low over Siberia moves to the Central
Bering Sea by tonight, and over the Chukchi Sea, Bering Strait,
and Eastern Bering Sea by Saturday morning. The high pressure will
hold on strong over mainland Alaska, and the front will deflect
to north over the Western Arctic. Leeside troughing north of the
Brooks Range develops on Saturday afternoon, so expect some gusty
Gap winds to develop there and diminish overnight. A rapidly
developing low pressure system will move to the Western Aleutians
Saturday morning at 978 mb, and move to the Pribilof Island by
Sunday morning at around 950 mb, and over Kodiak Island by Monday
morning at around 955 mb. Leeside troughing will develop north of
the Alaska Range Sunday so gusty Gap winds develop, and the
Tanana Valley Jet will set up through the Delta Junction area.
Expect the winds to diminish Monday.

Arctic Coast and Brooks Range...Low over the area is moving
slowly east and producing some upslope enhanced snows north of the
Brooks Range, expect that to continue today as the low moves east
and weakens, eventually dissipating as it merges with low pressure
to the east. Snowfall amounts will generally be less than 5
inches, with much lighter accumulations in the coastal areas.
Winds south of the low will be stronger than to the north of the
low with southwest winds 15 to 25 mph gusting to 35 mph, but
slowly diminishing as the low weakens. Around Anaktuvuk Pass and
Atigun Pass blowing snow may decrease visibility to less than a
mile for a while this morning. Temperatures will continue to
fall as the low moves east.

West Coast and Western Interior...Another quiet today. Some
clouds, some light snow or flurries moving through the area, but
generally less than 1 inch of snow. Winds generally less than 10
mph. Temperatures slightly cooler today and tonight, then warming
a few degrees Saturday and Sunday with low to the south sending
some warmer air north to the Bering Strait.

Central and Eastern Interior...Dirty ridge will keep the clouds in
the area, expect a few breaks, but they will generally be short
lived. An upper level shortwave will produce some light snow or
flurries as it moves southeast across the interior today. Snowfall
amounts generally less than 2 inches, with the heaviest snowfall
in the Alaska Range. Winds will generally be light and variable
today and Saturday. Leeside troughing will develop north of
the Alaska Range Sunday so gusty Gap winds develop, and the
Tanana Valley Jet will set up through the Delta Junction area.
Expect the winds to diminish Monday. Expect winds gusting to 45
mph in those areas Sunday diminishing late.

&&

Coastal Hazard Potential Days 3 and 4...A low will move to the
Pribilofs Sunday with strong northeast to east winds developing
over St Lawrence Island and Norton Sound. Current guidance
indicates this event has the potential to produce a surge of 2 to
3 feet in the area which would produce High Surf on the northeast
facing coast, including Savoonga.


&&

Extended Forecast days 4 to 7...Models are hinting at a strong
weather system moving to the West Coast and Bering Strait Thursday
night and Friday, but guidance has been relatively poor for the
extended periods so will continue to monitor.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

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

Small Craft Advisory for PKZ210-PKZ220-PKZ225.

&&

$$

SDB NOV 17


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