Gale Warning 836, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
403 PM AKST Thu Dec 11 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
(Days 1 through 3: This afternoon through Sunday evening)...

Key Messages:

- Gusty winds will continue through the extended forecast,
  Although wind diminish tonight into Fri. Winds increase again
  Fri night in Valdez, Seward/Resurrection Bay, as well as the
  waters around Kodiak Island. Northeast winds increase Saturday
  afternoon through Sunday across the Matanuska Valley. Still some
  uncertainty on the duration of how long gusty winds last.

- High Wind Watches issued for both Valdez (northeast gusts up to
  60 mph) and Thompson Pass (northeast gusts up to 75 mph) from
  late Friday night through Saturday evening.

- Cold temperatures and wind chills persist until at least the end
  of this week. A Cold Weather Advisory is currently in effect
  through Fri afternoon for the Copper River Basin and through the
  Thompson Pass area. Cold air across Southcentral has caused some
  rivers to begin freezing quickly. There could be some ice
  jamming of rivers as they freeze over. A hydrological outlook
  has been posted.

- You can reduce your risk of hypothermia or frost bite by
  protecting your skin from exposure and wearing appropriate
  clothing while outdoors. Keep emergency supplies with you in
  your home and while traveling whenever possible. Consider
  wearing your cold weather gear while you are driving through
  frigid temperatures. Know the signs of hypothermia and check on
  others.

Discussion:

Strong high pressure continues to take up real estate over the
Bering Sea with northerly flow spanning across Alaska. A trough is
over the Gulf with a weak low circulating well offshore towards
Southeast Alaska. As this trough moves out of the area to the
south and high pressure builds in, winds will gradually decrease,
becoming mostly calm this and evening afternoon, except for a few
lingering gusts across Whittier/Passage Canal, Valdez, and
Seward/Resurrection Bay.

The relatively calm, but very cold conditions will continue
through Friday morning. However, by Friday afternoon, a strong
upper trough drops into Southcentral. The first effect of this
trough is gusty winds in Whittier and Seward, reaching over 40 mph
through Saturday. Then, gusty winds return to the Matanuska
Valley, mostly picking up in earnest Saturday afternoon and
evening with gusts up to 50 mph, and Valdez, picking up beginning
Friday evening with gusts to 60 mph likely. Higher gusts up to 75
mph are likely across Thompson Pass. With that said, a High Wind
Watch has been issued for both Valdez and Thompson Pass late
Friday night through Saturday evening. Aside from the winds Friday
and Saturday, some snow showers may occur Friday across the Copper
River Basin and northern Susitna Valley as the 500 mb trough
arrives. Any snow is expected to be light in nature, if it makes
it to the ground at all due to how dry the air has been lately.

Another round of cold air also arrives on Saturday with this
trough. Apparent temperatures have the potential to be just as
cold or perhaps even colder with this arctic airmass. The Climate
Prediction Center's outlook for the next couple weeks continues to
favor towards colder than normal for most of the state. Cold
temperatures with the overall synoptic pattern persisting also
favors gap winds. Timing and intensity of the cold and winds will
continue to be the primary forecast challenge across Southcentral
through the next week.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tonight
through Sunday)...

A strong blocking ridge is centered over the central Aleutians
(Adak to Atka) and southern Bering Sea. A ridge axis extends
northeastward to Southwest AK and continuing to the AK Interior.
This ridge continues to provide mostly dry and cold conditions,
especially for Southwest AK and the AK Peninsula. A very weak
short-wave riding along top of the ridge brought flurries or
very light snow to portions of the Kuskokwim Delta today, but
the main impact has been increasing and lowering clouds. West
of the ridge, a storm is tracking across the Northwest Pacific.
The greatest impacts from the storm remain south and west of the
Aleutian Islands. Southeasterly winds are increasing from Adak
to Shemya with marginally warmer temperatures compared with the
rest of the forecast area.

A short-wave trough over the far northern Bering Sea will track
eastward toward northern AK through this evening, then begin to
dig southward across mainland AK overnight tonight through Friday.
Southwest AK will see a glancing blow from this, with areas of
light snow spreading from the Kuskokwim Delta to the Kuskokwim
Valley and interior Bristol Bay tonight through early Friday.
Snow in any given location will be brief in nature and accumulation
will be very light, with a dusting to a few tenths of an inch.
The bigger impact of this digging trough will be a reinforcing
shot of Arctic air and associated gusty winds. The strongest cold
air advection (and associated gusty winds) will be across the
interior Southwest AK, Bristol Bay and the Alaska Peninsula.
Winds will ramp up through the day Friday, then persist through
the weekend. The orientation if the low level flow is north to
north- northeast, which is not favorable for gap winds along the
Alaska Peninsula. Instead, winds will be uniformly strong (not
just confined to gaps), particularly for the coastal marine zones
south of the Alaska Peninsula and Kodiak Island. Temperatures will
initially jump up to the teens and 20s across Southwest AK as
winds develop Friday, but then will gradually fall through the
weekend - ultimately ending back up where we are right now.

Winds along the western Aleutians (from Adak west to Shemya) will
peak overnight tonight through Friday as the aforementioned storm
in the Northwest Pacific tracks to the far western Bering Sea.
There could be some spotty light rain, but it won't be much. The
upper ridge will then build westward, leading to diminishing
winds and quiet conditions through the weekend.

-SEB

&&

.LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)...

An expansive area of high pressure centered over the southern
Bering Sea descends south into the North Pacific by Monday
afternoon, while pushing gale force northerly winds across the
Alaska Peninsula. On the heels of the departing high, a shortwave
low will descend from eastern Russia Monday afternoon, but remains
offshore until it crosses the Alaska Peninsula by Tuesday morning.
With a large area of low pressure centered over the southern
Gulf, cold northerly flow will lower temperatures in the Copper
River Basin and bring high winds through gaps and passes from the
Alaska Peninsula to Thompson Pass, Valdez, and the Copper River
Delta. Dry conditions continue region- wide.

&&

.AVIATION...

PANC...Light northerly winds and VFR conditions will continue.

&&