High Wind Watch 2, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
425 AM AKST Tue Nov 7 2023

.SYNOPSIS...
Light snow moves through most of the Interior through today then
tapers off. A powerful low will move into the Gulf of AK then into
the Western Interior Wednesday night and Thursday, bringing more
accumulating snowfall. Strong northeast winds will develop ahead
of the low, blowing into the 30 to 50 mph range across the typical
windy areas. Blowing snow and strong east winds will continue
over the Arctic the next several days.

&&

.DISCUSSION...

Upper Levels and Analysis...
An elongated upper level trough is shifting northwest into the E
Interior from the Gulf of Alaska and Yukon Territory. Snow is
falling across the Alaska Range with this feature, and is already
moving north of the AK Range. There is a broad upper level low
with several embedded centers over the N Bering Sea and E Siberia,
with heights generally around 514 dam. There is a remnant high
over the Arctic north of Wrangel Island with heights around 540
dam. Finally, the NPAC jet stream is ripping at 175 knots. A
powerful mobile shortwave is forming a rapidly deepening low along
it across the E Aleutians moving east.

Model Discussion...
The models are in pretty good overall agreement with the general
pattern, but in this pattern the devil is in the details, and
there, the models are a bit muddier. What is known is after the
light snow event today for the Interior, a powerful ~965 mb storm
force low will move into the Gulf of AK Wednesday and Wednesday
night. This approaching low will rapidly increase Interior
pressure gradients and associated winds. After that, the low will
emerge somewhere west of Denali as it moves into the Interior from
the Gulf of AK, bringing widespread snow accumulations wherever
the low goes. That is the big question right now, with this
rapidly deepening low still way over the open Pacific waters. Thus
forecast certainty is not high, but there is enough certainty to
at least introduce accumulating snow to the Interior Wednesday
evening and Thursday, favoring the Western/Central Interior and
parts of the Tanana Valley. We are also expecting storm force wind
gusts over the Arctic Coast as this low deepens late week, which
will just push arctic winds even higher than they are now.

Central and Eastern Interior...
Light snowfall shifts north from the AK Range today, with the
general forecast on track for 1 to maybe 2 inches from the AK
Range to the White Mountains. Lower amounts less than an inch or
so can be expected farther north. This snowfall ends tonight with
a rapidly increasing pressure gradient in response to a deep Gulf
of AK low. We expect northeast winds to increase again over the
Interior highlands 30 to 45 mph, maybe higher in the real windy
spots. The Tanana Valley Jet will also crank along to 50+ mph
briefly Wed into Wed night.

The low will likely emerge near Denali and shift into the Central
Interior and Upper Koyukuk, bringing snow as early as Wednesday
and Wednesday night, and possibly into the White Mtns and
Fairbanks area by Thursday morning. There is a vast amount of
uncertainty for a system this close in, so stay tuned. For now,
snow doesn't looks heavy but there could be a band of 3 to 5
inches somewhere when it is all said and done.

West Coast and Western Interior...
A few snow showers continue over coastal regions and into the
Selawik Valley, otherwise, it will be mostly dry until a band of
light snowfall pushes west across the Interior and then into
Norton Sound and the YK Delta today and tonight. Snow
accumulations will generally be an inch or less.

Wednesday a low will shift northwest from the Gulf of AK, and it
will be a rather strong low, with rapidly increasing winds from
the northeast over the E Norton Sound and northward. Gusts to 45+
will be likely over the NW Arctic and into the W Brooks Range.
Meanwhile, snow will accompany the low and will begin accumulating
as early as Wednesday evening. Snow will shift across the region
to the coastal areas by Wednesday night with widespread snowfall
possible. Significant blowing snow will be likely from Kivalina
northward with blowing and falling snow and strong northeast
winds.

North Slope and Brooks Range...
No changes from thinking with a continuation of strong gale force
east-northeast winds and blowing snow mainly from Prudhoe Bay
westward to Wainright or so, where snow showers are accompanying
the blowing snow. Some mixed snow pellets will likely also occur
at times, with some possible freezing drizzle/rimed ice. Wednesday
night and Thursday a front will bring additional snow from the
south, across the Brooks Range, and will also tighten up the
pressure gradient Wednesday night into Thursday night, with storm
force wind gusts to 55+ mph likely, and significant blowing snow
possible.

Extended Forecast Days 4-7...
Friday and Saturday the first storm cycle is waning with a large
arctic low centered over the western half of the Mainland with
lows continuing to rotate across the Gulf of AK. There will still
be snow and blowing snow over the Arctic and West Coast with
chances for snow over the E Interior as weakening Gulf low
remnants shift inland.

A major pattern change is looking very likely as all the global
models and their ensembles show a powerful Siberia low shifting a
warm front across the Bering Sea, which would bring possible heavy
snow and blowing snow with south winds to the West Coast Sunday
into Monday.

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

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

AK...Winter Weather Advisory for AKZ802>804.
PK...Heavy Freezing Spray Warning for PKZ804-808>815-855>861.
     Heavy Freezing Spray Warning for PKZ805.
     Heavy Freezing Spray Warning for PKZ806.
     Heavy Freezing Spray Warning for PKZ807.
     Small Craft Advisory for PKZ810-856.
     Gale Warning for PKZ811.
     Gale Warning for PKZ812.
     Gale Warning for PKZ813>815-858-860-861.
     Small Craft Advisory for PKZ851.
     Heavy Freezing Spray Warning for PKZ852.
     Gale Warning for PKZ857.
     Gale Warning for PKZ859.
&&

Ahsenmacher