Blizzard in Alaska, January 30, 2017

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
115 PM AKST Sun Jan 29 2017

.DISCUSSION...

Models...Good agreement in the short term. Midrange and extended
periods have significant differences to the south of our forecast
area, but should not impact our forecasts. Much better agreement
today on the shortwave moving across the arctic Tuesday night and
Wednesday. Models initialized well against the 29/18Z surface
analysis.

Aloft...At 500 hpa...498 dam low over the Chukchi Sea will
continue to move north along 170W as it weakens. A shortwave
associated with the low will move north of the arctic coast by
Monday morning. A 498 dam low over the central Bering Sea will
move to the Gulf of Anadyr by Monday afternoon at 502 dam. A
trough associated with the low will move over the eastern Bering
Sea Monday morning and over the west coast Monday evening. A
shortwave will move over the northwest mainland Monday night into
Tuesday then moves east over the arctic coast. The main trough
will slowly move inland on Tuesday over the Western Interior, then
into the Central Interior by late Tuesday, and over the Eastern
Interior Wednesday morning. A ridge will start building north over
the western Aleutians Monday, and over the central Aleutians and
Bering Sea by Tuesday morning. The ridge will be over the eastern
Bering Sea and the Gulf of Anadyr by late Tuesday evening, and
moves over the southwest mainland coast and over the Bering
Strait Wednesday. A 564 dam closed low will cutoff from the ridge
and move north over the lower Yukon Delta Wednesday afternoon, and
will cover most of mainland Alaska by Thursday afternoon as the
center moves over Norton Sound at 567 dam. At 850 hpa...Cooling
trend continues into the evening, then a warming trend through
Wednesday will have temperatures rising 3 to 6 degrees celsius.

Surface...Ridging is building north over the mainland with a 1024
mb high over the Upper Susitna River Valley. Ridging will
continue to build north over the state with a 1042 mb high
developing in the Copper River Basin and a 1033 mb high in the
upper Yukon Flats by Monday morning. Leeside troughing north of
the Alaska Range will produce strong winds through the Alaska
Range through Tuesday morning. A 993 mb low in the Chukchi Sea
will continue to move north along 170W as it weakens. A 982 mb low
in the central Bering Sea will move northeast to 200 nm west of
St Lawrence Island Monday morning, then into the Bering Strait
Monday night as it weakens and dissipates as it continues into the
Chukchi Sea and merges with a 994 mb low that develops. A cold
front will move to the west coast Monday and push inland to the
Western Interior, then drag north. The ridge will slide to the
east a bit as the front moves in. A trough will develop over the
arctic coast and the front will drag east over the arctic as the
ridge recedes to the south. By late Tuesday a broad area of low
pressure will cover the arctic with ridging building back over the
mainland.

Arctic Coast and Brooks Range...Pretty busy over the northwest
arctic coast west of Point Barrow through Tuesday as a couple
weatehr systems move through the area. The last system will move
east across the arctic spreading snow east of Barrow. Expect 2 to
4 inches of snow along with gusty winds and blowing snow on the
northwest coast through Tuesday. Winds gusting to 40 mph south of
Point Lay with 10 to 20 mph winds for the remainder of the area.
Temperatures warming just a few more degrees through Tuesday, then
a sharp downward trend for the remainder of the week.

West Coast and Western Interior...Will continue to be active as
several system move through the area this week and the ridging
over mainland Alaska forces the systems to move north along the
dateline. Winter Weather Warnings will continue as some heavy
snowfall is expected Bendeleben Mountains on the Seward Peninsula,
along the south slopes of the western Brooks Range, and in the
Nulato Hills. Snowfall amounts across the area will range from
less than an inch to near a foot of new snow by the time things
wind up midweek. The heaviest snowfall is expected to start later
tonight and taper off Tuesday morning. As the low moves into the
area expect winds to kick up as well with gusts to around 50 mph
in the lower Yukon Delta, Norton Sound, the Bering Strait, and
Kotzebue Sound. Winds inland will be gusting to around 30 mph.
Blowing snow and fog will impact visibility at times. Temperatures
warm a bit as the snow moves in, then start cooling.

Central and Eastern Interior...Going to be relatively quiet in the
interior. Snow is exiting to the Northeast this afternoon and high
pressure is building in over the area. There will be a slight
chance for some snow Tuesday night into Wednesday morning as the
tail of the decaying front moves east across the area, otherwise
just a few clouds moving through. Gusty winds near the Alaska
Range passes through Tuesday morning with gusts to around 45 mph.
The remainder of the area will have variable winds to 10 mph. A
little cooler tonight, then warming a bit through midweek.

&&

Coastal Hazards Days 3 and 4...None.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Winter Storm Warning for AKZ207-AKZ208-AKZ210-AKZ211-AKZ212-
AKZ213-AKZ217.

Winter Weather Advisory for AKZ209-AKZ214-AKZ215-AKZ216.

Gale Warning for PKZ210.

Brisk Wind Advisory for PKZ200-PKZ215-PKZ220-PKZ225.

&&

SDB JAN 17