692
FXAK68 PAFC 171218
AFDAFC

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

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

A negatively tilted trough is extending from the Susitna Valley
southeastward into the northeastern Gulf this morning. This
feature, coupled with a developing surface low near the entrance
of Prince William Sound, is drawing moisture back over the Chugach
Mountains and over Cook Inlet. The result is persistent low cloud
cover and bands of light showers from north of Homer across the
Anchorage Bowl and over the Talkeetna Mountains. Farther east,
showers are also falling around Cordova and Valdez.

The upper-level trough will lift northeast toward the Copper
River Basin by mid to late morning, pushing the bulk of the
moisture eastward, farther over the higher peaks of the Chugach
and Talkeetna Mountains. However, as precipitation looks to wind
down over northern Cook Inlet and Anchorage, a trailing vorticity
lobe embedded in the weak westerly flow aloft will likely allow
for enough lift for the redevelopment of showers into the
afternoon for these locations. Precipitation will also become
more widespread across the Copper River Basin by this afternoon as
the downstream trough moves into the region.

An upper level low then drives over Cook Inlet from Southwest
Alaska late tonight into early Saturday. While the exact track and
strength of this feature is still a bit uncertain, this feature
will likely aid in the development of another area of showers from
Cook Inlet into the Mat-Su Valleys by late this evening, aided
again by moisture advecting westward from a surface trough over
Prince William Sound.

As the upper-level trough drops south into the western Gulf early
Saturday morning, colder air will move in quickly behind it. Any
lingering precipitation may fall in the form of snow across the
Upper Hillside of Anchorage.

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 Sunday, northerly surface flow should
inhabit really gusty conditions from getting into Whittier by
then. A stronger storm that once trended farther north with more
impacts for the Alaska Peninsula and possibly Kodiak Island for
Sunday afternoon and evening, has now trended farther south, with
less impacts for Kodiak Island with maybe some showers reaching
the island from the storm`s northern flank by Sunday evening.

TM/DAN

&&


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

A deep vertically stacked low continues tracking eastward along the
Aleutian Islands, with a frontal system pushing across the
Islands the Bering Sea. A short-wave on the leading edge of the
trough is leading to a band of rainfall ahead of the front,
spreading across the Eastern Aleutians this morning before
fizzling and moving south.

Cold air advection moving into the Kuskokwim Delta may bring a
transition to mixed rain/snow or possibly even all snow early
this morning along the Kuskokwim Delta coast. This is mostly
likely during periods of heavier precipitation as surface
temperatures will hover just above freezing, though no snow
accumulations are expected. Bethel and other inland locations
won`t see the colder air arrive until at least midday, which
favors precipitation remaining as mostly rain. A ridge moves over
Southwest Alaska today, bringing quieter weather conditions.

A plethora of short-waves will transit the Bering and Aleutians
through tonight, with multiple compact lows crossing the Bering
Sea. Confidence is low on the exact track of these features, but
impacts will be fairly low and localized. The upper level pattern
will once again amplify as we head through the weekend. However,
there have been some large shifts in the models on storm track,
trending much farther south with a North Pacific low this weekend.
While uncertainty is still high, it looks like the bulk of
precipitation and wind will remain south of the Alaska Peninsula
as the low tracks eastward, with little to no impact on Bristol
Bay and Southwest Alaska. Another deep low will approach the
western Aleutians Sunday, with good model agreement and much
better confidence in the track of this storm.

&&


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


Confidence is moderate that the general wind pattern through mid-
week across the North Pacific and Gulf of Alaska turns more
zonal. This west-east wind flow causes a deep North Pacific low to
move eastward through the Gulf of Alaska early next week and into
the Panhandle by mid-week. Multiple weak lows spin up off this
parent low and slowly move into Prince William Sound toward the
end of the week. As the parent low departs, weak ridging forms
over the Gulf of Alaska. A main low moves through the Bering Sea
and into the North Pacific mid- week. Cooler air filters into the
Aleutians and Alaska Peninsula in the wake of this low`s
departure. This low then progresses across the North Pacific into
the Gulf of Alaska. As this low weakens and turns more stationary
late next week, some models signal that it may take a
northeastward path around the aforementioned weak ridge. This path
would bring the low northward toward Kodiak Island/Kenai
Peninsula. Though exact the placement of these two parent lows
remains inconsistent, confidence remains moderate of zonal flow
through mid-week.

&&

.AVIATION...

PANC...MVFR ceilings and light winds will persist through this
morning with occasional light showers. MVFR visibilities are
also possible at times with any heavier showers and mist. Showers
may continue through the afternoon; however, any shower activity
near the terminal is expected to become more scattered in nature
with VFR ceilings at times. More widespread shower activity is
then expected to redevelop over the terminal by late this evening,
continuing into the overnight hours. Ceilings will again fall to
MVFR with some scattered clouds below 1,000 ft possible. By mid-
morning Saturday, winds turn northerly and increase as showers
move east and ceilings improve.

&&


$$