Winter Storm Warning 23, NWS Fairbanks, AK

Northern Alaska Forecast Discussion
National Weather Service Fairbanks AK
308 AM AKST Wed Nov 8 2023

.SYNOPSIS...
An active and dynamic Pacific pattern is now in place as a
powerful storm force to near hurricane force low is rapidly
deepening over the Gulf of AK. This storm moves inland over the
next two days, bringing snow to parts of the Interior, strong
winds to the Interior highlands and Alaska Range, and possible
high winds to the Arctic Coast.

***Thereafter, the signal is now very strong for a significant
winter storm to move into the West Coast and Western Interior
Sunday and Monday.***

&&

.DISCUSSION...

Upper Levels and Analysis...
There is a powerful upper level trough over the western half of
the Gulf of AK which is forming along the EPAC polar jet stream.
There is a basal low rapidly deepening along the associated warm
front currently around 45N moving due northward. A leading warm
front is moving into the Gulf Coast with a large cirrus plume
moving northward into the Interior across the AK Range. There
remains an arctic high N of Wrangel Island, now at 1035 mb. There
is a 975 mb low currently south of Kodiak Island with a rapidly
tightening interior gradient due to this low. East winds continue
over the Arctic Coast around 30 knots.

Model Discussion...
The suite of hi-resolution and global numerical weather models are
all rather similar in their depiction of weather across the
Mainland the next few days, much better overall agreement than
they had been in the last few days. Confidence is high that snow
will overspread large swaths of the Mainland west of the E
Interior along with strong winds as the low plows inland across
the Alaska Range Thursday. The hi-res models were favored for
winds with a blend of models for everything else including
precip. For P-type, added in mixed precip chances for the E
Interior as the low plows inland due to the amount of warm air
aloft.

Central and Eastern Interior...
Interior winds continue to increase today ahead of a powerful Gulf
of AK low. The Tanana Valley Jet and higher elevation Interior
highlands will see ranges of 35 to 50 mph, possibly locally higher
near Delta Junction at times. The surface low crosses the Alaska
Range Wednesday night and Thursday and south winds will briefly
blast through the AK Range gaps, possibly gusting to near 70 mph.

A second warm front will shift north this evening with chances for
accumulating snowfall rapidly increasing from the Alaska Range to
the Upper Koyukuk and Lower Tanana Valley. A chance of wintry mix
precip including pellets and sleet is possible from Fairbanks
eastward as a slot of warm air aloft will be in place. However,
downslope flow will be strong and will keep the E Interior on the
drier side. Generally expecting 2 to 4 inches of snow possible NW
of Livengood with 1 to 2 inches across the AK Range, possibly 4+
on S facing slopes. Temps will warm to near freezing or higher for
the E Interior by Thursday.

West Coast and Western Interior...
Snow showers and flurries will continue over the YK Delta and
parts of Norton Sound today. A second batch of heavier snows will
move into the Yukon Valley and shift across the Seward Peninsula
and NW Arctic through tonight, continuing in bursts through
Thursday as a deep low from the Gulf shifts into the W Interior
and then to the Seward Peninsula by Friday. Snow will wrap around
the low through Friday. Total accumulations will be in the 2 to 5
inch range over the Interior and less over the coast. Kivalina to
Point Hope will likely see significant periods of blowing and
drifting snow as winds crank up to 60+ mph.

Extended Forecast Days 4-7...
Broad low pressure aloft over the Mainland will start the extended
period Saturday. The first storm of this cycle is falling apart
and the arctic high weakening over the coast, so winds are also
coming down. However, the next storm is now expected to be moving
into the West Coast as early as Sunday, and confidence is now high
that this front will bring widespread snowfall and blowing snow
to the West Coast, as this storm will be tapping subtropical
moisture. This storm looks to track into the Chukchi Sea so it
will eventually bring some higher waters to the West Coast, too.
Snow shifts inland through Monday. There is the possibility of
another strong Bering storm Tuesday through Thursday moving
inland, and this storm will be potentially tapping into a 4+ sigma
subtropical precipitable water anomaly, so stay tuned. Right now,
this storm cycle looks likely, but details remain uncertain this
far out.

Coastal Hazard Potential Days 3 and 4...Possible coastal elevated
water threat with storm surge Sunday and Monday.

&&

.AFG WATCHES/WARNINGS/ADVISORIES...

AK...High Wind Watch for AKZ801.
     High Wind Watch for AKZ802>805.
     Wind Advisory for AKZ812-832-834-846.
     Wind Advisory for AKZ837.
     Wind Advisory for AKZ847>849.
PK...Heavy Freezing Spray Warning for PKZ804-805-807-808-810>815-
     855>861.
     Small Craft Advisory for PKZ804-805.
     Heavy Freezing Spray Warning for PKZ806.
     Small Craft Advisory for PKZ806-852-854.
     Small Craft Advisory for PKZ807.
     Small Craft Advisory for PKZ808.
     Brisk Wind Advisory for PKZ809.
     Gale Warning for PKZ810.
     Gale Warning for PKZ811>815-857>861.
     Small Craft Advisory for PKZ816.
     Small Craft Advisory for PKZ817.
     Small Craft Advisory for PKZ850-855.
     Small Craft Advisory for PKZ851.
     Heavy Freezing Spray Warning for PKZ852.
     Small Craft Advisory for PKZ853.
     Gale Warning for PKZ856.
&&

Ahsenmacher