Gateway, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

668
FXAK68 PAFC 220104
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
404 PM AKST Sun Dec 21 2025

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

* Wind Advisory in effect for the Matanuska Valley until 6PM this
  evening. Winds 20 to 30 mph with gusts up to 55 mph possible.

* Cold Weather Advisory in effect for the Copper River Basin and
  Thompson Pass through 11AM Tuesday. Cold temperatures 30 to 40
  below with wind chills as low as 50 below possible.

Gusty winds will gradually diminish through this evening. As
northerly winds begin to settle with weakening northerly flow and
a relaxing north- south pressure gradient, very cold temperatures
will return across interior valleys from tonight into Monday. Lows
in the -10s are likely early Monday for the coldest spots across
the Mat- Su, Anchorage and Kenai Peninsula, with -30s to -40s
already entrenched across parts of the Copper Basin expected to
stick around for at least the next day or two. From Monday into
Tuesday, northerly gap winds will tick back up as a mid to upper
level jet streak wrapping around a strengthening upper ridge out
west pushes east into Southcentral. Thankfully, this setup does
not look nearly as supportive for high winds compared what we are
seeing with the ongoing wind event. Gusty winds will mainly pick
back up in and around Whittier, Seward, Kodiak and Valdez as the
day progresses on Tuesday. For the rest of Southcentral, dry,
clear and cold conditions will persist into midweek.

&&


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

The first of two fronts is making its way over coastal Southwest
Alaska early this afternoon. The front is pushing up against a
ridge over mainland Alaska, which will work to inhibit the front
from progressing further eastward than about coastal Bristol Bay.
The front is bringing a wave of snowfall to much of the coast,
Kuskokwim Delta, Bristol Bay, and portions of the Alaska
Peninsula. The front will stall out across western Southwest this
evening, however will be quickly succeeded by a more potent trough
diving into the eastern Bering after midnight tonight. This
trough will bring a broad surge of moisture, pushing into the
coast by early Monday morning. This system will be organized
enough to persist beyond the coast and push snowfall further
inland. Snowfall lingering around Southwest will result in total
snow accumulations of 2-4 inches across Southwest Alaska through
Tuesday morning. Inland areas near Aniak and Sleetmute to see
slightly less accumulations.

Temperatures across Southwest will rise steadily with the passage
of these fronts. The latter system, coming Monday morning, will
bring The majority of the Aleutian Chain will remain unaffected
by the passage of these troughs, with the ridge axis continuing to
promote inactive weather with southerly winds for the western
Aleutians, and northwesterly winds for the eastern Aleutians
through Tuesday.

-CL/MJB

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

A strong upper level ridge slowly drifting east later this week
will keep much of the AKPen and southern Alaska mainly clear,
cold, and dry through midweek. By Thursday night into Friday, a
potent shortwave flattens the ridge as it drives south out of the
Arctic and across the interior before deepening into a closed low
over southern Alaska and the northern Gulf by the weekend. This
trough will bring increased chances for snow across Southwest
Alaska and mainly along the northern/interior side of terrain
across Southcentral for mid to late this week. As this system
progresses south into the Gulf, it brings a renewed threat for
high winds late next week across typical locations, including the
Matanuska Valley, Valdez area/Thompson Pass, and along the
southern AKPen and Gulf coast. The Arctic airmass associated with
this trough will keep temperatures below average across southern
Alaska, with the coldest areas being the Copper River Basin and
interior Southwest Alaska, where ambient temperatures will hover
in the range of 20 to 30 below zero. Deterministic models begin to
diverge by the weekend on the placement of a low developing in
the Gulf, while ensemble means support the low development in the
vicinity of Prince William Sound bringing increased chances for
snow mainly along the Gulf coast through the weekend. Further
west, a stronger ridge builds back across the Bering Sea as the
pattern amplifies.

&&

.AVIATION...

PANC...VFR conditions expected to persist through the period.
Northerly winds will continue to decline this afternoon and
evening...remaining north-northwest this evening then light and
variable Monday morning.


&&


$$