Gale Warning 124, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
456 PM AKST Tue Jan 28 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through
3/Tonight through Friday Morning)...

A broad upper level low continues to slowly make its way
southeastward towards interior Alaska. A shortwave moving through
the bottom of the low will help pull it down across Southcentral
this evening, ushering in more arctic air and increasing the
chances for snow showers along Cook Inlet tonight, from the Mat-Su
down to the southern Kenai Peninsula. As this feature rotates and
lifts northeast, periods of light snow will be possible over the
Copper River Basin. Accumulations are expected to be light;
however, any snow could linger into Wednesday.

As the low continues southeast into the Gulf on Wednesday, flow
across the region will switch to more westerly and then northerly,
rapidly increasing gap winds. Blizzard Warnings for Broad Pass
and Isabel Pass down to Paxson are in effect from midnight tonight
through 9 AM Thursday, and for Thompson Pass from 3 AM Wednesday
until 3 PM Thursday. Snowfall from our recent storms will be
easily resuspended with gusts reaching 30-55 mph, reducing
visibility down to one quarter mile at times. With the cold air
continuing to stream in, wind chills could reach as low as 40
below zero for interior locations and mountain passes. Whittier
and Seward will also see strong gusty winds from tonight into
Thursday morning. The low pressure system will track towards
Southeast AK on Thursday and into Friday morning, pulling the cold
air mass to the east. Gap winds will gradually decline through
the day, with Thompson Pass being the last to die down.

In addition to strong winds through gaps and passes, expect
strong winds across the coastal water along with falling
temperatures. The result will be the development of widespread
freezing spray beginning Tuesday night and Wednesday. Heavy
freezing spray is likely along the Alaska Peninsula from southern
Cook Inlet through Shelikof Strait.

&&

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

Key Points:

* Cold Weather Advisories out for the Kuskokwim Delta tonight
  through Thursday morning and the lower Kuskokwim Valley
  Wednesday night through Thursday morning for wind chill values
  as low as 40F to 50F below zero.

* Blowing Snow Advisory has been issued for the Pribilof Islands
  for Wednesday afternoon/evening, ending after midnight.

* Winter Storm Watch has been issued for the Kuskokwim Delta Coast
  and Western Capes Thursday morning through late Thursday night
  for possible Blizzard conditions.

A cold airmass is still in place over much of Southwest Alaska,
keeping temperatures in the single digits or subzero today, with
widespread subzero temperatures expected overnight. Very cold wind
chills as low as -40F to -50F are expected across the Kuskokwim
Delta tonight and spilling into the lower Kuskokwim Valley by
Wednesday night. Temperatures are not expected to warm up until
Friday afternoon as a warmer air mass moves in behind an
approaching warm front.

The aforementioned front is currently situated over the Western
Aleutians, bringing rain and gale force winds to the region. The
front will spend the next few days progressing eastward across the
Bering towards Southwest, with no significant weakening until
after making landfall. Thus, there is a higher chance for snow and
blowing snow across the Pribilof Islands ahead of the warm air.
Up to 4 inches of snow is possible, with winds gusting to 55 mph
and visibilities reduced to one-half mile Wednesday
afternoon/evening. Warmer air behind the front will transition
snow to a rain/snow mix and then all snow by Wednesday night. The
front reaches the Southwest Coast by Thursday morning, bringing
snow and winds. There is much colder air in place over Southwest
Alaska compared to the Pribilof Island and is expected to warm as
a slower rate. This allows for higher potential for Blizzard
conditions along the Kuskokwim Delta coast and Western Capes of
Bristol Bay. Snow accumulations of up to 10 inches is possible,
with winds gusting as high as 35 mph and visibilities reduced to
one-quarter mile. Further inland towards Bethel may see periods of
blowing snow with reduced visibilities and up to 7 inches of snow
accumulation Thursday through Thursday night.

-KM

&&

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

A well developed upper level ridge moves across Mainland Alaska
through the weekend. Over the Bering, a broad upper low spins
several shortwaves through the pattern, briefly flattening the
Interior ridge. This first shortwave spreads areas of snow over
the Western Alaska coasts and inland through the Yukon Valley.
Snow will diminish by Sunday, as the ridge re-establishes itself.
Another shortwave supports a front with areas of moderate rain and
gusty winds over the Western and Central Aleutians and Bering
through Tuesday. Areas of gale force winds develop closer to the
low center in the Northwest Bering for Sunday, diminishing Monday.
The gusty winds move into the Eastern Aleutians and Bering late
Sunday into Monday, continuing into the Alaska Peninsula, Bristol
Bay and the West coast for Tuesday. Most of the Mainland areas
return to seasonably colder temperatures under partly to mostly
cloudy skies.

-KZ

&&

.AVIATION...

PANC...VFR conditions should persist through the TAF period. There
is a chance a some flurries or very light snow showers this
afternoon into the evening as a weak upper disturbance lifts over
the area. A lower cloud deck could form as a result of snow shower
activity, but VFR should be maintained. Gusty south-southwesterly up-
inlet winds will turn northerly by this evening. A few gusts between
15 to 20 kts are possible Wednesday as a reinforcing shot of cold
air works in by then.

&&