Brisk Wind Advisory 73, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
231 PM AKST Wed Feb 28 2018

.DISCUSSION...

Models...There has been very good agreement in the solutions over
the past week or so, especially in the short term. Midrange there
was some divergence, but that cleared up the last few days, most
likely due to the building high amplitude ridge building and
slowing everything down. Solution remain in good agreement, but
expect that will change as the pattern becomes more active over
the state as the ridge moves over the Yukon Territory by Friday
night. Along the western fringe of the forecast are with will be
active into the weekend and the 28/12Z solutions seem to have a
good handle on things. Will generally use a blend since solutions
are in good agreement, but leaning on the NAM for winds which
bring in slightly stronger winds tonight and tomorrow over the
West Coast. Will be using mostly the SREF for precipitation
probability.

Aloft...At 500 hpa...Low over the Beaufort Sea persists, but has
weakened to 501 dam today. It will move southeast over over
Observation Pt NWT by Thursday afternoon as it continues to fill
to 511 dam. It will be quasi stationary into Friday, then move
north over Banks Island and by Sunday morning it will be over the
northeast Arctic at 502 dam. High amplitude ridge that has been
building is over the Eastern Bering and Chukchi Seas extending
northwest over Wrangel Island over the Siberian Arctic today. By
Thursday afternoon the axis will lie from southern Kodiak Island
to Ruby to Wainwright, and north, and by Friday afternoon it will
lie from Cordova to Central to Flaxman Island and north. The ridge
will be pinched off over the Central Arctic, and the southern
portion will continue to rotate over the Yukon Territory by
Saturday morning. A 494 dam low over the northwestern Bering Sea
will move over Siberia, but the associated longwave trough will
move east over the Dateline by Thursday afternoon, and lie from a
532 dam low 300 nm south of Sand Point, northwest over the Gulf of
Anadyr by Friday afternoon. A shortwave will develop in advance of
the longwave trough, and move to the Eastern Bering Sea coast by
Thursday evening, then northeast over inner Norton Sound, and the
southern Chukchi Sea early Friday morning, and to the western
Brooks Range late Friday morning, and over the Arctic Friday
evening as it helps cutoff the ridge. Longwave trough moves over
the West Coast Friday night, and into the Interior Saturday. At
850 hpa...-20 isotherm has pushed south over the Eastern half of
the state to lie from McCarthy to Denali to Allakaket to
Wainwright, and will move east to lie over the AlCan Border by
Thursday afternoon. The -10 Isotherm is over the Gulf of Alaska to
Kodiak City to Emmonak then north of St Lawrence Island this
afternoon, and by Thursday afternoon it will lie from Yakutat to
Palmer to Denali to Wainwright. It will continue to slowly move
east into Friday. The zero Isotherm will make a cameo appearance
over the southwest Mainland and Lower Yukon Delta Thursday
morning, but retreats to the south late Thursday evening.

Surface...A broad area of high pressure over mainland Alaska
extends north over the Central Arctic. The 1039 mb center will
move into the interior tonight and will in the Upper Tanana Valley
at 1047 mb by Thursday morning, and slides over the Yukon
Territory by Thursday evening. A 1045 mb center will develop over
the Upper Yukon Flats by Thursday morning and move east of Fort
Yukon by Thursday evening. Weak high pressure will persist over
the upper Yukon Flats through Saturday morning. A 960 mb low in
the western Bering Sea will move north into Siberia Thursday as a
weather front moves to the Eastern Bering Sea and Bering Strait
Thursday morning, and over the West Coast and Chukchi Sea Friday
morning as the low moves near Wrangel Island. Leeside troughing
develops north of the Alaska and Brooks Range Thursday night with
increased winds north of the ranges. A second weather front will
move to the Central Bering Sea Friday morning, and the Southwest
coast and Bering Strait Friday evening. A bubble high will develop
in advance of the second front and move over the Interior Friday
morning. High pressure over the Pacific will build north over the
southern Bering Sea and rotate east over the Pribilof Islands
Friday evening with high pressure extending northeast over the
western interior and the Upper Yukon Flats. The low over Wrangel
Island will move northeast into the Arctic and drag the leeside
trough over the Arctic Coast into the offshore waters.

Arctic Coast and Brooks Range...Weather system moving into the
Chukchi Sea spreading clouds over the Northwest and Central Arctic
tonight and eastern Arctic Thursday as the ridge aloft continues
to move east. Strong winds moving to the Northwest coast overnight
will increase from the south and gusting to around 65 mph west of
Point Lay, so will issue a Blizzard Warning. Increasing clouds to
the east and there is a big patch of stratus that shows up on the
SPoRT NPP VIIRS 24 hour Microphysics product at 28/2035Z that is
over the western half of the Arctic Plains and Coast moving
northeast, but will turn more to the north this evening. Expect
the lower clouds to move into the Barrow and Nuiqsut areas, but
stay west of Deadhorse at this time. Winds turning from southwest
to southeast over the remainder of the area tonight and increasing
to 10 to 20 mph, then increasing Thursday to 15 to 30 mph.
Temperatures a few degrees warmer the next couple days.

West Coast and Western Interior...Strong winds moving into the
Eastern Bering Sea currently will continue east with the strongest
winds moving to the northeast into the Chukchi Sea. Heavy
precipitation with the front will move to St Lawrence Island and
the Bering Strait this evening, the Seward Peninsula and Chukchi
Sea Coast Thursday. Heaviest snowfall will be on St Lawrence
Island and the southern Seward Peninsula. Blizzard Warnings and
Winter Weather Advisories have been issued for the coastal areas.
Strongest winds will be over St Lawrence Island through the Bering
Strait and over the Northern Chukchi Sea Coast with winds gusting
to at least 60 mph. Gusty winds will push inland to the Norton and
Kotzebue Sound Coasts, but decrease east of the Nulato Hills. A
surge of warmer air into the lower Yukon Delta tonight, but it
cools pretty rapidly Thursday.

Central and Eastern Interior...Mostly clear and colder tonight and
Thursday, then increasing clouds with warmer temperatures. Cloudy
with some flurries or light snow Friday, but nothing significant.
Winds generally light, but Tanana Valley Jet will kick up a Bit
Friday around Delta Junction with gusts to around 35 mph. Gap
winds kick in as well in the Alaska Range with gusts to 45 mph
from the south. Looking into next week there will be another round
of snow to start the week.

&&

Coastal Hazard Potential Days 3 and 4...Another wind event
expected on Saturday night into Sunday around the Bering Strait,
but expect winds to be less than 40 mph and even with diminished
ice coverage do not expect any issues.

&&

Extended forecast for days 4 to 7...Solutions continue to show
very good agreement in the short term, but as the high amplitude
ridge breaks down and a more active pattern develops expect them
to diverge quite a bit on strength and location of the major
features, and the details will become very fuzzy. For now a blend
of the Ensemble and latest solutions will provide a reasonable
base to build on. With that said, the cycle looks to continue with
a snowy period Sunday through Tuesday over most of the area with
clearing later next week.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

High Surf Advisory for AKZ213.

Blizzard Warning for AKZ201-AKZ207-AKZ209-AKZ213.

Winter Weather Advisory for AKZ210-AKZ211-AKZ212-AKZ214.

Heavy Freezing Spray Warning for PKZ210.

Gale Warning for PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-PKZ230.

Brisk Wind Advisory for PKZ235.

&&

SDB FEB 18