Small Craft Advisory 101, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
525 AM AKST Fri Jan 31 2025

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

Quiet, clear and very cold conditions are still on track into the
upcoming weekend. Temperatures will steadily but slowly warm each
day through Sunday as a strong subsidence inversion develops
under the ridge as it continues to build overhead. Gap winds will
also very slowly drop off with time as the cold air mass and high
pressure over interior valleys both begin to moderate, though
drainage flow out of the Copper Basin could be a bit stubborn to
drop off through the Copper Delta and Thompson Pass. The coldest
temperatures with this Arctic air outbreak are likely occurring
this morning over most of the interior valleys and lower
elevations as clear skies, calming winds and low dew points
combine to create very favorable conditions for the surface to
radiate out heat. Precipitation chances will stay close to zero
through the start of next week.

-AS/CJ

&&

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

Snow showers across Southwest Alaska are ongoing this morning,
especially over the Kuskokwim Delta where a blizzard warning
remains in effect through noon today. Snow began yesterday as a
trough moved over the region. Gusty winds and heavy snow over
Mekoryuk resulted in visibility down to zero for multiple hours. A
front is now quickly approaching the Kuskokwim Delta this
morning, which will maintain snow showers through the morning
hours, with snow eventually expanding across the Lower Kuskokwim
Valley and interior Bristol Bay through this evening.

The forecast has changed little the past 24 hours and a warming
trend remains expected today and tomorrow across Southwest Alaska
as southwest flow behind the front pushes into the coast. Daytime
highs in the upper 20s and lower 30s are forecast across the
Kuskokwim Delta and coastal portions of Bristol Bay today and
tomorrow. For interior Bristol Bay up into the Lower Kuskokwim
Valley single digits into the teens are forecast.

A quick glance at satellite reveals a large occluded upper low
between Kamchatka and the Western Aleutians. This low is lifting a
front across the Central Aleutians with showery conditions noted
over Adak. The presence of the low and a building ridge of high
pressure over the Alaska Peninsula will maintain showery
conditions and an axis of small craft winds and gales from the
Central Aleutians into the Eastern Aleutians. By Saturday a new
upper low is forecast to lift into the western Bering. This next
low will bring another round of widespread gales and building seas
to 20 feet for the Western and Central Aleutians.

-BL

&&

.LONG TERM FORECAST (Days 4 through 7: Monday Through Thursday)...

The high amplitude flow pattern over the Alaska Region will
undergo some brief duration but significant changes through the
forecast period. An upper level Kamchatka low retreats into the
Russian Arctic, while its elongated trough through the Central
Bering slacks up a bit due to transitory shortwaves through
midweek. The upper level North-South ridge over Mainland Alaska
will be flattened somewhat on Wednesday during the shortwave
passages. However, the ridge re-establishes itself in a broader,
more tilted orientation from the Gulf of Alaska across Western
Alaska into the Bering by Thursday. Model confidence using a
clustered GFS/ECMWF/Canadian blend for the larger scale features
remains quite good, while reducing the uncertainty over the finer
details.

A Kamchatka surface low extends a front through the Western and
Central Aleutians and Bering for Monday. Southerly winds with
locally moderate snow on the leading Northern edge of the front
changes to rain through the Central Aleutians and Bering and
dissipates in the Northern Bering late Tuesday. A North Pacific
low and front slip across the Western Aleutians late Tuesday.
Locally moderate rain and gusty winds with areas of gale force
gusts spread over the Western And Central Aleutians and Bering
Wednesday and Thursday. Interior Alaska lingers under more
seasonal temperatures and variably cloudy skies.

-KZ

&&

.AVIATION...

PANC...VFR conditions and light northerly winds will prevail
through the TAF period.

&&