Brisk Wind Advisory 49, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
237 PM AKST Thu Jan 31 2019

.DISCUSSION...

Synopsis...Mainly clear and cold in the interior with deep strong
inversions through Saturday. Temperatures falling into the 20s and
30s in most locations from Galena northeast and east tonight, then
from Tanana east Friday night. Warming trend starts Saturday for
the Central and Eastern Interior as a weather front moves to the
West Coast, then pushes east into the Interior. Pretty quiet on
the Arctic, but winds do pick up Friday as troughing develops over
the Plains and the winds flip around from the east. West Coast
will be most active area with a weather front moving to areas
from the Seward Peninsula south Friday night, then over most of
the West Coast and Western Interior Saturday.

Models...31/12Z solutions are actually in pretty good agreement
big picture wise. They area lacking in agreement on the details
so far, but expect they will iron that out the next couple runs.
When initialized against the 31/18Z surface the high over the
Yukon Territory was about 3 mb weaker than the solutions,, the
high near Wrangel Island was 2 mb weaker, and the low southwest
of Shemya was about 4 mb deeper, but overall not too bad. Going
with a mostly NAM solution today for both winds and precipitation.
Will just be tweaking the temperatures for the short term.

Aloft...At 500 hpa...Ridging over mainland Alaska with ridge axis
over the Western Arctic to has Noatak to McGrath, then southwest
over Bristol Bay. Lower heights over Canada associated with low
over Nunavut. There is a 532 dam low in the Northeast Pacific off
the Queen Charlotte Islands, a 489 dam low 200 nm southwest of
Shemya, and a 498 dam low over the North Pole. By Friday afternoon
the ridging over the mainland will lie from a 538 dam high over
Ambler to a 537 dam high over Denali then south over Seward. A low
will develop over the Yukon Territory this evening and move over
the Southern Yukon Territory by Friday afternoon at 510 dam as the
low off the Queen Charlotte's moves southeast over British
Columbia and eventually merges with the low to the north. Low to
the southwest of Shemya remains quasi stationary into Friday as a
trough moves from the southwest Bering Sea to lie over the
Northern Bering Sea to St Lawrence Island to Cape Romanzof to
Chignik by Friday afternoon. Low remains near the Pole at 493 dam
with a shortwave swinging around over the Eastern Siberian Arctic.
And by Saturday afternoon the shortwave that moved over the
mainland Friday will dissipate as ridging persists with some
reenforcement that moves in behind the shortwave. The ridging
will lie over 150W in the Arctic over Nuiqsut to Tanana to
southern tip of Kodiak Island. Low over the Yukon Territory will
move southeast. The low southwest of Shemya will move north over
the Coast of Kamchatka with a 498 dam low developing over the
Gulf of Anadyr and a shortwave extending southeast from the low to
Unalakleet. Strong flow develops on the western flank of the
ridge and several shortwaves will move up the West Coast as the
ridge slides east over the AlCan Border by Sunday afternoon.
Stronger shortwaves develop in the flow and will push into the
Interior Sunday and Monday. At 850 hpa...The -20C isotherm lies
from the AlCan Border crossing to Atigun Pass to Deadhorse and
will lie from Summit Lake to Central to Atigun Pass to Demarcation
Point by Friday morning. It starts moving east Friday night, but
will hang on over the Upper Tanana Valley through Saturday. The
-10C isotherm lies from Denali to Point Lay and will remain in the
same general area through Saturday, then moves northeast as
warmer air pushes in over the southwest mainland.

Surface...High pressure lies from a 1031 mb high in the west
central Yukon Territory northwest to a 1038 mb high in the Arctic
Plain to a 1037 mb high 200 nm northeast of Wrangel Island.
Troughing over the Beaufort Sea and MacKenzie Bay with a 1023 mb
low 500 nm north of Deadhorse. To the west a decaying weather
is moving to the southwest coast this afternoon and will work
inland and north as it weakens spreading snow north to the Seward
Peninsula Friday night before dissipating. Troughing develops
north of the Brooks Range and the Western Alaska Range Friday with
a strong pressure gradient developing across the ranges. A
second, stronger, weather front will move to the northeast Bering
Sea Saturday morning with a much tighter pressure gradient over
the West Coast and adjacent areas as a 968 mb low develops near
the Gulf of Anadyr. High pressure will persist over the Yukon
Territory with a 1041 dam center in the Upper Tanana Valley. As
the second from moves to the coast the high pressure will start to
weaken and pull back to the east. Tight pressure gradients across
the ranges will be enhanced as high pressure persists over the
Upper Yukon Flats, and the Upper Tanana Valley. Tight pressure
gradient also develops over most of the interior summits, and in
the Upper Tanana Valley Tanana Valley Jet will kick as cold air
lingers over the Yukon Territory.

Arctic Coast and Brooks Range...Generally not too bad, some
stratus over the Eastern Brooks Range, and the Arctic Coast east
of Flaxman Island. Some blowing and drifting snow developing as
the winds snap around from the east along the coast and pick up
to 10 to 20 mph. Also strong gusty winds developing near the
Brooks Range passes with gusts to around 35 mph from the south
Friday and Saturday. Travel on the Dalton Highway may be impacted
by blowing and drifting snow north of Atigun Pass. Temperatures a
little cooler the next couple days, then slowly warming from the
west.

West Coast and Western Interior...Weather front moving to the
coast will be weakening, but strong enough to spread snow north to
the Seward Peninsula before it dissipates. A second front will
bring a mixture of snow and rain to the Lower Yukon Delta
Saturday, with snow to from Nome north. The second low will also
bring a whole bunch of winds with it and Winter Storm Watches have
been issued for several coastal areas. Will continue those
watches, but latest model guidance indicates winds may not be as
strong as previously forecast so will keep the watches in effect
for tonight, but expect updates early Friday morning. Temperatures
will be warming. Second weather front has potential for
significant snowfall in the Middle Yukon Valley and the Upper
Kuskokwim Valley Sunday.

Central and Eastern Interior...Clear and cold tonight and Friday
night with lows falling into the 20s and 30s below for most
locations. High tomorrow 5 to 15 below. Some winds on the summits
gusting to 35 to 40 mph will create blowing and drifting snow that
may impact travel, so will continue the Winter Weather Advisories
that are currently in effect. Warming from the west by late
Saturday as a weather front pushes clouds in from the west, with
snow spreading into the area Sunday. Temperatures will be the big
challenge the next couple days as winds aloft may work down to
the surface in some locations and that will bring much warmer than
forecast temperatures to those areas.

&&

Extended forecast for days 4 to 7...Clear and cold will give way
to another round of snow with 2 to 4 inches of snow in the Central
and Eastern Interior Monday. In the Arctic snow will be spreading
east with 1 to 3 inches of snow. On the West Coast and Western
Interior expect clearing for a day or so, then another weather
front will move into the area from the south bringing a mix of
rain and snow to areas from the Seward Peninsula south Tuesday
through Wednesday.

&&

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

Winter Weather Advisory for AKZ218-AKZ219-AKZ220-AKZ221.

Winter Storm Watch for AKZ207-AKZ209-AKZ211-AKZ213-AKZ214-AKZ215.

Brisk Wind Advisory for PKZ200-PKZ210-PKZ215-PKZ220-PKZ225-
PKZ230.

&&

SDB JAN 19