075
FXAK68 PAFC 270101
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
501 PM AKDT Thu Jun 26 2025

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

This afternoon, satellite imagery reveals a quasi-stationary,
occluded, complex low pressure system roughly situated southeast
of Kodiak Island with mid level clouds streaming northward into
Cook Inlet, the Kenai Peninsula, and farther inland. Coastal
ridging has built in along the Gulf coast as well, setting up a
pressure gradient between Cordova and Anchorage, and thus the
Turnagain Arm wind has picked up again this afternoon. To a lesser
extent, the Knik Arm and Copper River Basin gap winds have been
elevated as well. A few showers are making their way northward and
pushing into the Gulf coast. Aloft, there is a broad upper low
component tied to the aforementioned surface low with several
localized areas of vorticity waves rotating around its periphery.
One of these shortwaves has made its way out of the area into the
Fairbanks region, and due to anticyclonic (negative) vorticity
advection helping subsidence build in the wake of the shortwave,
the lack of instability will likely keep thunderstorm chances
lower this afternoon and evening in comparison to previous days.

Farther south, the low`s front will make very slow northward
progress, not reaching the Gulf coast until late Friday or early
Saturday. Rain will likely remain for Kodiak Island through much
of the short term forecast. Showery conditions and small craft
conditions are also forecast from the Shelikof Strait and the
Barren Islands. Across the Gulf, winds will be around 20 kts along
the front. A wave of precipitation may develop ahead of the front
as it lifts toward the northern Gulf, but winds and precipitation
chances overall diminish late Friday as the front dissipates
along the Gulf coast. Friday will thus see improved conditions
across the Gulf as well as improved conditions farther inland of
Southcentral. A few showers and isolated thunderstorms may develop
along the foothills of higher elevations, including the eastern
slopes of the Talkeetna mountains Friday afternoon.

The potential for precipitation chances across Southcentral
increases for this weekend as an easterly shortwave moves across
the Copper River Basin. Models still differ on timing and overall
strength of the shortwave, which makes confidence of details of
the forecast lower than average. However, based on current model
guidance, there could be a few lightning strikes associated with
storms that may develop Saturday afternoon as colder air moves in
aloft with the wave, steepening lapse rates as it does so. Not
only does this provide instability, but it also can increase
rainfall rates. Precipitation chances then appear to spread into
the Matanuska and Susitna Valley Saturday afternoon and may
stretch southwestward into Anchorage and the western Kenai
Peninsula as a combination of the deformation band and added
energy of the wave phases. Another added possibility is that
dynamics could align well enough to have a mesolow form and work
its way southwestward. Again, models still are not in agreement on
the timeframe as some models are holding off until Sunday morning
for any precipitation, and there is still a question of how much
rainfall the area could see. If some of the short to mid range
guidance today is correct, much of Southcentral could see a
soaking rain to start the work week, especially in places with
orographic enhancement. Details will become more clear over the
next few days.

-McCormick/Rux


&&


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

The next 72 hours: The trough over the Bering Sea pushes east as
high pressure briefly builds over the Aleutians. A shortwave moves
across Interior Alaska tonight into tomorrow morning causing rain
in the Kuskokwim Delta. A fast moving low pushes the high into
the North Pacific Ocean during the day Saturday.

The low just south of the Alaska Peninsula caused an easterly
wave to move through the Alaska Peninsula and portions of the
Southwest coast today. Rainfall amounts recorded through 4:00 pm
were a few hundredths of an inch in the area. This rain will
continue to diminish through the evening.

Two distinct shortwaves will bring light rain showers in the
Kuskokwim Valley and Delta are likely through tomorrow afternoon.
The first arrives this evening and will continue into tomorrow
afternoon. This fast-moving shortwave progresses across the
Kuskokwim Valley. This will bring the greatest chance of rain
from Aniak to Bethel to Cape Newenham northward. This is a more
northward track than yesterday. Therefore, rainfall amounts will
be light ranging from a few hundredths to a tenth of an inch. The
second shortwave moves north to south as the aforementioned high
migrates closer to the SW Mainland. Northerly flow will bring this
second wave of moisture from the Interior southward into the
Kuskokwim Valley tomorrow evening into Saturday afternoon. As the
wave moves southward, pockets of heavier rain showers and
isolated thunderstorms are possible. The potential for widespread
fog in the Aleutians and Bering Sea increases as high pressure
builds.

&&
.LONG TERM FORECAST (Days 4 through 7: Monday through Thursday)...

A broad, closed upper level low over the Gulf of Alaska maintains
its overall sojourn around the Gulf of Alaska and Eastern North
Pacific. Some additional support from a shortwave rotates around
the center with little change in strength through the forecast
period. A upper level Bering ridge eases over Western Alaska by
Thursday. Gaining some strength from the remnants of Tropical
Depression Sepat, an elongated trough over the Bering becomes a
closed upper low through the week. The overall guidance comes from
the GFS through the entire period, where the differences extend
with the rest of the models through the week mostly in the Western
portions of the region. An increased use of model ensemble
guidance is required after Tuesday.

The week opens up with a fairly strong Northwest Bering surface
low. Its front extends over the Bering and Western Alaska to the
Aleutians with locally moderate rain and breezy conditions, before
the Aleutian portion slides into the North Pacific late Monday.
The front continues moving into the Alaska Peninsula and Southwest
Alaska for Tuesday, diminishing Tuesday night as the surface low
moves across the AKPEN. Locally moderate rain and isolated
thunderstorms subside over the Eastern Interior Alaska nearer the
Canadian border through Monday. Scattered showers remain across
most of the Southern Interior through Thursday.

- Kutz

&&


.AVIATION...

PANC...VFR conditions prevail through the TAF period. Turnagain
Arm winds have come in a bit stronger than anticipated this
afternoon, and gusts to around 30 kts out of the southeast at
times will remain possible trough around 6z or so this evening.
Winds will diminish overnight, but will return again tomorrow
afternoon at a lower intensity.

&&


$$