904
FXAK68 PAFC 220117
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
417 PM AKST Fri Nov 21 2025

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

An area of low pressure currently over the western Sound and soon
to overspread Whittier continues to be the focus for winter
precipitation this afternoon and tonight. Current radar shows
light returns from the Knik Arm down through Cook Inlet,
Anchorage, and the Kenai Peninsula, with additional returns
pushing into Prince William Sound and the coast. Snow has been
persistent across Homer and Seldovia where a winter weather
advisory remains in effect for 4 to 10 inches of total snowfall
through Saturday morning. Snow has been much lighter elsewhere
from Kenai into Anchorage, and only a dusting to possibly one half
inch is forecast. Temperatures have warmed to above freezing
along portions of the Seward Highway from the eastern Turnagain
Arm down to Seward, and rain has been the primary form of
precipitation. However, temperatures are expected to drop below
freezing again later this evening/tonight with an additional 1 to
3 inches forecast from Girdwood to Turnagain Pass.

As the low continues to lift further inland light precipitation
will remain possible through early Saturday morning while also
expanding into the Susitna Valley. Model guidance has a second
smaller trough dropping south from interior Alaska, converging
upon the Southcentral low, with a brief chance for a second round
of snow spreading into western portions of the Susitna Valley
after midnight tonight. Accumulations here will also only amount
to a dusting.

Precipitation across Southcentral clears out over the weekend
with cooler temperatures to set in across the region. As soon as
precipitation comes to an end on Saturday morning the potential
for patchy fog will increase across the Mat-Valley, Anchorage
Bowl, and Western Kenai Peninsula. Expect highs on Saturday to
remain below freezing for all but coastal locations. Temperatures
will trend cooler into Sunday with morning lows in the teens for
the MatSu and Western Kenai Peninsula, to single digits across the
Copper River Basin.

-BL

&&


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

A compact low pressure system diving across the Alaska Peninsula
(AKPen) will promote gusty northwesterly winds out of favored gaps
and passes on the southern side of the AKPen this evening
diminishing tonight. As the low exits south, northwesterly winds
will be drawn down the eastern Bering along portions of the
Southwest Coastline. Simultaneously, a shortwave moving south over
the Kuskokwim Delta will bring a quick shot of snowfall to the
region tonight. Expect up to 2 inches of new snowfall from this
wave. These systems will work in tandem to create a period of
blowing snow across the Kuskokwim Delta. The worst conditions are
expected along the coast, from Kipnuk to Toksook Bay 9pm to
midnight tonight.

Temperatures will trend steadily cooler across the Bering Sea and
Southwest Alaska in the wake of this low, with low temperatures
dropping into the 20s for the Alaska Peninsula Saturday and Sunday
nights, with single digit lows for the interior Kuskokwim Delta
and Lower Kuskokwim Valley. Freezing fog over the greater Bristol
Bay region is possible Saturday morning. Out west, a North Pacific
low lifts to near the Western Aleutians by Saturday. Its front
brings strong winds, up to storm- force (50 kts) across the
western and central Aleutians along with moderate to heavy rain.
The low remains south of the Aleutians through the weekend, its
front lifting slowly into the eastern Aleutians through Sunday
night. Southwest Alaska remains dry and cold under offshore flow
on Sunday. Sunday night/Monday morning may see negative low
temperatures from the lower Kusko Valley into the Kuskokwim Delta.

-CL

&&


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

Starting on Tuesday, a vertically stacked low and large cyclonic
circulation will be centered south of the Aleutians in a weakening
phase. Short-waves embedded within the circulation will track from
east to west from the western Gulf/Kodiak Island across the Alaska
Peninsula and Bristol Bay and continuing westward across the
southern bering Sea. None of the features look particularly
strong, so would expect areas of precipitation and wind with
typical winter- time impacts. Precipitation-type will be mainly
rain, with Bristol Bay being the only location cold enough to see
snow. The upper low will open up into a trough by Thursday
(Thanksgiving), causing winds and precipitation to diminish.

Meanwhile, a strong ridge in the Arctic will build southward over
the northern half of mainland Alaska. This looks far enough south
to block any short-waves from the Aleutian trough from reaching
interior SW AK or Southcentral AK. Thus, expect seasonably cool
and dry conditions for these areas Tuesday through Wednesday. A
short-wave will dig down the east side of the ridge on Wednesday,
across the Yukon and into the Copper River Basin. This will bring
marginally colder temperatures, though accompanying cloud cover
will likely limit temperature drops. This trough will force the
upper ridge to retreat back northward and allow a short-wave
trough to approach Southcentral on Thursday. Model agreement with
this feature is not great, but ensembles generally support this
idea. With a cold air mass in place over Southcentral, the most
likely outcome would be widespread light snow arriving sometime
Thanksgiving Day.

As we continue to Friday, model guidance is in excellent agreement
on amplification of the upper level flow and development of an
Atmospheric River. However, as would be expected this far out in
time, there is large spread in the location of the ridge/trough
and track of a leading surface low from the Pacific. This evolving
pattern does have good potential to bring higher impact weather
to southern Alaska, with strong winds, mixed precipitation-types,
and warming temperatures. Stay tuned as we monitor the location of
key features and identify the areas where the greatest impacts
are most likely.

-SEB

&&

.AVIATION...

PANC...AN area of low pressure over western Prince William Sound
will continue to pinwheel moisture and cloud cover over Anchorage
and the terminal through early Saturday morning. MVFR ceilings are
expected to persist through late this afternoon then lower to low
MVFR or IFR ceilings and vis as steadier light snow develops.
Light snow should taper off by 12z, early Saturday morning, as the
low weakens and moves inland.

Lingering low-level moisture and a weakening wind flow in the
lower half of the atmosphere will likely result in low stratus
remaining over the terminal through Saturday morning. There is a
chance that this cloud deck either continues to lower through
early to mid morning, or erodes just enough to result the
development of fog due to additional radiational cooling. Either
way, clearing behind the low is not expected. Moreover, any drier
air aloft coupled with lingering low stratus and/or fog, could
result in some light flurries or freezing drizzle early to mid
Saturday morning. Right now, this is a low confidence solution,
but will be monitored.

&&


$$