576
FXAK68 PAFC 180005
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
405 PM AKDT Fri Oct 17 2025

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

A negatively tilted trough continues to extend from the Susitna
Valley southeast across the extreme northeastern Gulf this
afternoon. At the base of this trough is a weak surface low
pressure spinning just south of Prince William Sound. This low
continues to weaken through early Saturday morning as it drifts in
place. Scattered showers will continue to persist across the
northern Gulf Coast and the eastern half of Prince William Sound
through this evening.

A stronger upper disturbance is currently approaching western
portions of Southcentral from the Kuskokwim Valley. Current
returns from the Kenai Radar are showing some rain showers making
it over the Western Alaska Range and into the Susitna Valley this
afternoon. Precipitation associated with this upper-level system
will move eastward with time. Rain moves into Anchorage, the
Matanuska Valley, and the Upper Kenai Peninsula by late this
afternoon into early this evening and persists into late tonight
to early Saturday morning. Precipitation moves east into the
Copper River Basin for tonight into Saturday with rain/snow mix
becoming all snow late tonight north of the Edgerton Highway.
Along the Edgerton, expect rain and rain/snow mix to persist due
to warmer temperatures in the low to middle 30s. The best chance
to see a few inches of accumulating snow will be around the
Eureka/Tahneta Pass areas as well as around the Paxson area. If
there is enough leftover moisture very late tonight into early
Saturday morning, the Upper Hillside of Anchorage could see some
snow flakes and perhaps a very light accumulation, but this is not
guaranteed.

After Saturday morning, most precipitation becomes confined to
the mountain ranges of the Copper River Basin as a weak upper-
level shortwave drops in from the north. Precipitation then tapers
off across most interior locations by Sunday morning with dry
conditions expected into Monday. Precipitation makes its way back
to coastal areas for Sunday night and Monday (more on this in a
bit).

As the trough and associated cold air advection moves southeast
across the Gulf through Saturday, gusty gap winds increase out of
Seward, Whittier, Thompson Pass, and the marine zone complex of
Valdez. While gusty northern gap winds through Thompson Pass and
Valdez Narrows persist into Monday, northerly surface flow should
inhabit really gusty conditions from getting into Whittier by
Sunday. A light easterly component is even possible for Passage
Canal/Whittier Sunday as the pressure gradient reorients. Whittier
winds and Passage Canal winds look to pick back up from the west
on Monday as a front lifts towards the Gulf Coast by then.

Speaking of the aforementioned front lifting towards the Gulf
Coast for Monday, the parent low pressure to this front has
trended back to the north from the south trend yesterday. As a
result, Kodiak Island will be wetter and windier Sunday night into
Monday with most of the heavy rain being confined to the Gulf
waters. Rain looks to also reach the Eastern Kenai Peninsula and
Western Prince William Sound Monday morning with rain perhaps
clipping portions of the northern Gulf Coast as well. The
strongest winds still look to remain on the southern flank of this
system in the North Pacific with some gale-force gusts over the
Gulf waters. This system moves to the eastern Gulf and Southeast
Alaska by Monday evening. Stay tuned to further forecast updates
as details become more clear regarding this next frontal system
for Sunday and Monday.

&&


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

The previous low in the Bering continues to weaken as it moves
east and its remnants will push towards the Gulf of Alaska by the
end of the day. In its place is weak ridging with embedded
shortwaves for tonight through Saturday. The ridging will be
stronger over the mainland, allowing for lower precipitation
chances and partly cloudy skies. There is a chance for patchy fog
in the Kuskokwim Delta tonight as skies clear out. However, the
fog shouldn`t be widespread due to unfavorable north-northwesterly
winds. Speaking of north-northwesterly winds, cold air advection
will continue in the Southwest Mainland, casing temperatures to
slowly cool through the end of the short term forecast. The
Kuskokwim Delta and the Lower Kuskokwim Valley will see the
coldest temperatures dropping to the mid to upper 20s during the
nighttime hours.

A North Pacific Low will rise and barely brush the Central and
Eastern Aleutians Sunday morning, allowing for northeasterly to
northerly small craft winds and some precipitation to impact those
areas. This low will reinforce the northerly flow in the
Southwest Mainland, keeping cold air advection going. At the same
time all of this is going on, a larger low pushes into the Western
Aleutians. Gale force winds and moderate precipitation is
associated with this low. There is also a possibility for storm
force winds in the southern part of the low south of Amchitka. By
Monday afternoon, the low will track eastward into the Eastern
Aleutians and the Pribilof Islands, bringing small craft winds.
Weak ridging with embedded weak waves become prevalent behind the
low. After this point, more cold air advection will occur due to
northerly winds throughout the Bering and the mainland.
Temperatures will likely continue to drop through the middle of
the week as the core of the cold tongue moves over the region.

-JAR

&&


.LONG TERM FORECAST (Days 4 through 7)...

Upper level troughing over Mainland Alaska and a broad surface
low in the western Gulf of Alaska early this week will progress
into the eastern Gulf of Alaska through midweek. While relatively
good model agreement indicates most energy and associated rainfall
with this system will be directed towards southeast Alaska,
periods of rain can still be expected along the immediate coast
for the eastern Kenai Peninsula and Prince William Sound as
several weak perturbations rotate north into the northern Gulf
Coast. Eastward progression of this storm in the Gulf will promote
gusty northwesterly winds across the AKPen for Wednesday into
Thursday, with a cooler airmass spreading across the Bering and
much of the Mainland.

Guidance points to the jet stream becoming more zonal in the
North Pacific and in the Gulf of Alaska late in the week. Multiple
areas of weak low pressure across the Bering Sea, North Pacific,
northern Gulf of Alaska will keep much of the region under a
generally showery regime. Exact placement of these lows remains
uncertain and inconsistent, but confidence remains moderate that
the pattern remains rather progressive in the zonal flow.

&&

.AVIATION...

PANC...VFR conditions are expected to give way to marginal
ceilings during the evening as more light rain moves into the
area. This rain should end before morning as winds turn more
northerly and increase late tonight/early tomorrow morning. The
strength of these winds will help determine how fast the cloud
cover dissipates Saturday. Generally VFR conditions are expected,
especially as the Saturday progresses.

&&


$$