Heavy Freezing Spray Warning 31, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
222 AM AKDT Tue Oct 26 2021

.SYNOPSIS...
The storm track remains well to the south of the Mainland, which
is keeping a weak pressure gradient in place. A front which
brought snow to the Interior and the North Slope has shifted
north of the Arctic Coast this morning. A closed arctic low
remains in place over the NW Arctic Borough, keeping snow showers
and blustery NW winds in place. Over the Interior, extensive
stratus and flurries have been left behind the departing front.

&&

.DISCUSSION...

Upper Levels and Analysis...
A series of lows tracks across the NE Pacific in conjunction with
the polar jet. Upper troughing dominates the Mainland, with the
main center over the NW Arctic Borough, with a 500 hpa height of
approximately 504 dam. A shortwave trough is seen lifting
northward across the Arctic Coast, with the associated front
moving offshore. Extensive stratus is occupying the Interior with
a very weak pressure gradient in place. The surface low over the
NW Arctic is the only surface feature of interest, which is
analyzed at approximately 987 mb near Point Hope. ASCAT winds show
this low to be at gale strength on the western periphery of the
low.

Model Discussion...
The numerical weather models are in very good agreement with the
large scale pattern, but are in much less agreement with the
details regarding several low amplitude waves of energy lifting
north across the AK Range from the Gulf of AK for the next couple
days. The overall consensus is for a surface low to form over the
Yukon Flats Tuesday night and Wednesday then shift north, bringing
areas of light snowfall. For now will continue to favor a blend of
models to average out the inconsistencies and to depict widespread
light snow chances through Wednesday. Out west, a blend of models
was favored to depict the low over the Chukchi Sea as the models
are not in good agreement with the exact placement of this low
after tonight given the cold core nature of this feature.

Central and Eastern Interior...
Extensive low clouds, fog, and perhaps some flurries will persist
today, with light snow developing tonight as a subtle disturbance
aloft shifts north across the Alaska Range and from the Yukon.
Snow accumulations by Wednesday night, after the low exits north
of the Brooks Range, will be around an inch or less most places,
with 1-2" for the AK Range and the southern Brooks Range. The low
exits for Thursday with partially clearing skies, which will
result in falling temps at night and during the day.

West Coast and Western Interior...
The surface low is now pretty much parked over the Chukchi Sea
with wraparound northwest winds impacting the coast. This low will
continue to spin in place bringing coastal snow showers and
blustery NW winds early today before diminishing briefly tonight.
A separate low over the N Bering Sea will shift east into the YK
Delta bringing snow showers chances and gusty northeasterly
offshore winds Wednesday. The low over the Chukchi Sea will
continue to bring snow showers and periodic NW winds into the 30
mph range before weakening through Thursday. For the Interior,
pretty quiet weather with low stratus and periodic fog, especially
near the Yukon River.

North Slope and Brooks Range...
A few lingering snow showers end this morning as the associated
weakening front moves offshore. More light snow chances move into
the Brooks Range and North Slope on Wednesday with very light snow
accumulations possible. Temps gradually cooling with weakening
gradients after today. Expect periods of dense fog to accompany
the lighter winds.

Extended Forecast Days 4-7...
The extended forecast still looks quite active for the weekend as
Friday starts out under the influence of the arctic high and
mostly quiet weather. The flow amplifies rapidly on Friday night
as a deep Pacific low, the former remnants of a tropical system,
move into the NE Pacific and shift inland, binging the threat for
heavy snowfall over the West-Central Interior and strong chinook
flow across the Alaska Range into the Eastern Interior. The
amplified southerly flow pattern looks to continue into next
week, although model uncertainty after Sunday is very high. Stay
tuned...

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...
Heavy Freezing Spray Warning for PKZ235-PKZ240-PKZ245-PKZ500.

Small Craft Advisory for PKZ220.
&&

AHSENMACHER OCT 21