Storm Warning 120, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
502 AM AKDT Tue Oct 21 2025

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

Quiet weather persists for most of Southcentral this morning as a
trough continues to move through the Yukon Territory and a ridge
spreads across the area. The next low expected in the Gulf is
currently south of Kodiak Island. Rain chances will gradually
increase throughout the day as the front lifts north. Kodiak can
expect precipitation to begin this afternoon. For the northern
Gulf and Prince William Sound, precipitation is possible this
afternoon ahead of the front expected to arrive later tonight.

Gale force winds is expected along the front. As the low
continues northward however, winds could reach 50 knots along the
coast Wednesday afternoon and north-south gaps could become
especially breezy. Despite the big picture of the forecast
remaining consistent, models have struggled to come into agreement
over the position of this low for Wednesday and Thursday. The
variation in the details lowers the certainty in the strength of
winds and the location of precipitation expected, especially for
Cook Inlet communities. The latest guidance is favoring a more
westward track with stronger northerly flow, small craft to
perhaps gale force winds through Prince William Sound, and
orographic lift for precipitation. Moderate precipitation rates,
heavy at times, is forecast for western Prince William Sound and
eastern Kenai Peninsula. Downsloping is forecast for the Anchorage
area and western Kenai Peninsula, but a brief spillover of
precipitation is possible overnight Wednesday into Thursday.

Expect a broad upper level trough to linger for the Gulf and
southcentral Alaska for the rest of this week. With weak upper
level forcing, timing winds or precipitation will be further
complicated by another low from the north Pacific moving into the
Gulf Thursday and a trough from southwest Alaska sinking into the
western Gulf. Overall, a generally persistent weather pattern is
setting up for the latter half of this week. Each feature embedded
in the upper level pattern will play a key role in the
enhancement of the precipitation and wind outcome for the rest of
the week.

Rux

&&

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

The low pressure system that spread rain across the Aleutians and
southern Alaska Peninsula (AKPEN) yesterday can be seen on
satellite imagery moving into the Gulf of Alaska this morning.
Cold northerly flow will follow on the backside of the low,
increasing winds through gaps and passes of the Eastern Aleutians
and AKPEN. Gusts up to 40 mph are possible this morning before
weakening this evening.

Another system is already bringing rain and gusty winds to the
western Aleutians this morning and is set to impact the central
Aleutians later today as it tracks southeastward. Model guidance
is in good agreement that this low will take a southern track and
phase with the aforementioned low in the Gulf by Wednesday,
shifting flow back to northerly over the Eastern Bering and
reinforcing cold air over the region. Expect increased gusty winds
over the Kuskokwim Delta, Bristol Bay, and AKPEN Wednesday
afternoon into Friday.

Weak upper level shortwaves rotating around Wednesday's Gulf low
may interact with an upper-level low along the Kuskokwim Delta
Coast to produce some light snow along the Kuskokwim Delta
Wednesday evening. Light snow moves farther inland to the
Kuskokwim Valley and Bristol Bay for Thursday. A cold upper-level
over Kamchatka on Friday is poised to send another shot of cold
air southeastward across the western Bering starting Thursday
evening and Friday morning as portions of mainland Southwest
continue to contend with snow showers by then.

&&

.LONG TERM FORECAST (Days 4 through 7: Friday - Monday)...

Continued upper-level trough extending across the Bering Sea,
mainland Alaska and the Gulf of Alaska will persist through the
extended forecast period. This will produce multiple low pressure
systems tracking across the Aleutians and into the Gulf of Alaska,
causing unsettled weather in the Gulf of Alaska and into the
southeastern portion of the state. Model guidance is in rare
agreement with this weather pattern continuing into early next
week. Western Alaska will remain seasonably cool with northerly
winds and few weather impacts to hamper ongoing relief operations
through the weekend.

-DD

&&

.AVIATION...

PANC...VFR conditions and light, northerly winds persist.

&&