Gale Warning 14, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
501 AM AKST Sat Jan 13 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Some lingering scattered showers over the northern Gulf this morning
as the frontal boundary continues to wash out. The dampened ridge
will reamplify today as large NW-to-SE oriented low continues to
hamper much eastward progression and a strong occluded low lifts
through the Aleutians and up towards southwest Alaska. By tomorrow,
the large Canadian low will be pushed northwards and the ridge will
finally be able to move east into western Canada...finally breaking
down the blocking pattern that has been in place much of the past
week.

The front associated with the low lifting north into the Bering Sea
will lift to the northeast today. The gradient will once again
tighten over the western Gulf as the front nears Kodiak Island this
morning with gales expected south and west of Kodiak. The Barren
Islands and Kamishak Bay will also see winds increase to gale force
as the front passes over Kodiak Island this afternoon. With the low
taking a more northerly track, winds should decrease by tonight.

While this system will bring another round of rain for Kodiak Island
and rain/snow to the eastern Kenai Peninsula and Prince William
Sound through tomorrow, the western Kenai up through the Mat-Su
Valley look to see only a quick shot of snow. Easterly to
southeasterly flow should keep the western Kenai, Anchorage Bowl,
and Mat-Su downsloped to start, but as winds veer to more southerly
then southwesterly, should see a period of light snow work up the
Cook Inlet to the Valley late tonight into Sunday morning. Overall
snowfall totals of only an inch or two look reasonable given current
guidance and progressive track of the system; however, a few of the
higher resolution models are hinting at a localized band setting up
along the Turnagain Arm into Anchorage with could bump up totals
slightly if this solution plays out. The Copper River Basin should
also see some light snow develop in portions of the basin as the
surface low moves towards the Prince William Sound then up and over
the Chugach Mountains. High pressure then looks to build back over
Southcentral with quiet weather expected once again on Monday.

- PP

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Monday night)...

The well advertised strong North Pacific low is currently making
its way over the eastern Aleutian Chain and into the southeastern
Bering Sea this morning. So far, Nikolski has recorded wind gusts
of up to 70 mph this morning, while Saint George Island has gusted
up to 60 mph. The High Wind Warning for the Eastern Aleutians
remains out until 9AM this morning. The Winter Weather Advisory
for the Pribilof Islands also remains in effect until 9AM this
morning where reductions in visibility to one-half mile are still
possible with combination of strong northwest winds and falling
snow. Conditions will begin to improve tonight for the Eastern
Aleutians, Southern Alaska Peninsula (AKPEN) as the winds die
down with the storm moving northward towards Kuskokwim Bay and the
Kuskokwim Delta.

As the system moves northward to the Kuskokwim Delta, it will drag
in cold air eastward off the Bering Sea and into the area. This
cold air advection in conjunction with snow falling into gusty
northwest winds will cause reductions in visibility along the
Kuskokwim Delta Coast north of Kipnuk and Nunivak Island. Thus, a
Winter Weather Advisory has been issued to address these impacts
and goes into effect tonight until early Sunday morning.

Meanwhile, a low pressure system in the vicinity of Kamchatka will
send its gale-force front eastward across the Western Aleutians
today. A ridge forms to the east of the front and helps to draw up
sub-tropical moisture from the south to provide soaking rains for
the western Chain through Monday morning before the frontal
boundary weakens. The Kuskokwim Delta and perhaps western portions
of the Bristol Bay coast will see more snow and rain/snow mix
from this front Sunday night into early Monday morning before
drying out for most of the rest of the day. The tail end of the
frontal system from the low that will now be in the Chukchi Sea
will clip the Kuskokwim Delta and Lower Kuskokwim Valley with more
light precipitation Monday night as a broad ridge builds over the
Bering Sea.

&&

.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)...

An upper level high moves into the Central Bering, and expands
across most of Interior Alaska through the forecast period. The
strength and extent of this high suggests the beginning of a
blocking high which lasts beyond the end of the weekend. Model
confidence is high with the greatest variance between models along
the Canadian border. A series of lows slide across the Arctic
before diving Southward over the Alaska-Canadian border for
Thursday. This sets up a closed low center over the Southern Gulf
Thursday into the weekend. Weather becomes relatively quiet, with
the exceptions of gusty winds over the Western Bering, diminishing
for Thursday. Areas of outflow winds develop along the Alaska
Peninsula and Southcentral Coasts, with gale force gap winds
through the Barren Islands and Shelikof Strait and along the
Alaska Peninsula Coast into the Eastern Aleutians developing for
Thursday and diminishing Friday. Interior Alaska may see Bora-
type winds, bringing cold air with the gusty winds to much of
Southcentral.

Kutz

&&

.AVIATION...

PANC...VFR conditions and light northerly winds will persist
through Saturday night. An increasing southeasterly winds along
the mountains and through Turnagain Arm Saturday evening
through early Sunday morning may bring LLWS over the terminal.
Expect MVFR ceilings overnight Saturday into early Sunday morning.
Ceilings and vis are then both expected to drop to IFR by 3 am
Sunday as snow moves over the terminal. Snow should end by mid
morning Sunday as winds shift to the southeast.
&&