426
FXAK68 PAFC 050039
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
439 PM AKDT Fri Sep 4 2026

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

The general forecast remains on track through about Sunday
afternoon. Then, forecast confidence diminishes regarding a North
Pacific low that curves northeastwards across Kodiak Island and
along the north Gulf coast from early Sunday morning through
Monday. Still, with only weaker systems in our area for the next
few days, the outlook for Labor Day Weekend will be unsettled but
mostly benign weather, with no major hazards anticipated.

Diving into the details... a pattern change continues as the
upper level ridge that brought nice weather the past few days
moves slowly east, only to be replaced by broad southwesterly flow
and exposure to waves of energy from the broad trough out west.
More widespread rain is expected overnight and early Saturday
morning as a stronger shortwave moves over the area quickly from
southwest to northeast. Most of the rain should be out of the
population centers by Saturday afternoon, but some lingering rain
is expected in the upslope areas of the Mat-Su Valleys and along
the eastern Sound. One area to watch will be northern and central
Copper River Valley, where the shortwave will bring colder air
aloft and upper level forcing around the time of peak afternoon
heating, leading to thermal instability and a slight chance for
thunderstorms.

For Sunday and Monday, another shortwave and surface low will
move from Kodiak into the north Gulf with light rain spreading
inland Sunday evening and continuing through Monday morning.
Models are struggling with how various upper level shortwaves will
phase in the North Pacific, which is leading to uncertainty with
the track of the surface low moving into Southcentral. Compared to
yesterday, the latest deterministic model guidance looks to be
taking the low track a bit further east, which could mean a faster
tapering off rain from about Kenai Peninsula north and west.
While confidence is lower with exact rain amounts and timing,
confidence is fairly high that much of Southcentral will see
cloudy skies and light rain with this storm.

&&


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

Water levels will remain elevated at high tide for Kuskokwim Delta
coast communities Saturday morning, but flooding is not expected.
There will be a slight downward trend in water levels with high
tides on Sunday and Monday.

A high amplitude long-wave trough remains parked over the Bering
Sea and north-central Pacific. A corresponding downstream ridge
extending from the Northeast Pacific to mainland AK is slowly be
pushed eastward toward Canada as a steady stream of short-wave
troughs ride up and over it. While a weak vertically stacked low
continues to spin in the western Bering Sea, the primary feature
of interest today remains a north-south oriented cold front over
Southwest AK. This is leading to rain and low clouds for much of
Bristol Bay and the Kuskokwim Valley. Rain did lighten up
overnight through this morning and become a little less
widespread. However, a negatively tilted short-wave trough is
moving up from the Pacific toward the AK Peninsula and Bristol
Bay, leading to rainfall intensification and expansion in area.
Otherwise, the weather across the Bering and Aleutians is
generally benign - especially for September. Lastly, a compact
gale force low tracking eastward across the North Pacific is
beginning to curve northeastward toward the Aleutians as the upper
short-wave begins to amplify.

For tonight, the cold front and associated rain will continue to
progress north and east across interior Southwest AK, from King
Salmon to Iliamna and Port Alsworth northward to Sleetmute,
Stoney, and Lime Village. Steady rain will exit late tonight
through tomorrow morning, though low ceilings and showers will
linger.

Models have shifted with the track and strength of the next two
storm systems coming out of the Pacific and there have been some
fairly substantial adjustments made to the forecast, especially
for wind and waves. The current system in the North Pacific looks
stronger and further north with its track tonight through Saturday
night. This will bring stronger southeasterly gap winds to the
Aleutian chain (from around Seguam Island eastward) to the Alaska
Peninsula on Saturday, with 25 kts or higher for most of the gaps.
As the parent low weakens near or south of Dutch Harbor Saturday
night, a secondary low will form south of the Alaska Peninsula
and Kodiak Island, enhancing winds across nearby coastal waters.
As for rainfall with these storm systems, expect a fairly short
duration as the lows track along the Aleutians and AK Peninsula.
Model spread is large with depiction of upper level short-waves
tracking across the Southwest mainland Saturday night through
Sunday night. Coastal areas most likely (60-70%) will see periods
of rain, with lower confidence in rainfall as you head inland
(30-50%).

With progressive flow aloft, another storm system will track out
of the Pacific to the Aleutians on Sunday and into the southern
Bering Sea on Monday. This storm looks larger than Saturday`s
systems, but of a similar strength. Model spread is also fairly
large with the exact track of this low, but the forecast reflects
the general idea of enhanced winds/waves and rainfall.

-SEB

&&


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

A low digs into the Gulf of Alaska bringing locally heavy
rainfall to the Prince William Sound region Wednesday. Current
guidance on the timing and exact location of the low crossing the
state remains low but confidence remains high of a change to an
overall wet pattern for most of Southcentral next week. Persistent
southwesterly flow behind this low will continue to bring weak
fronts through Southwest Alaska into the middle of next week.
Confidence of a late-week low moving through the Bering Sea
continues to increase despite differences in the heaviest rainfall
location, strongest winds and overall onshore timing of its
front.


&&
.AVIATION...

PANC...Ceilings aer expected to remain just above MVFR conditions
this afternoon and then improve a little through the evening as a
southeasterly Turnagain Arm wind moves over the terminal and
moderates some of the low level moisture that has been moving up
Cook Inlet. Winds should peak overnight into early Saturday
morning at the same time that the steady rainfall moves into the
area. Both ceilings and visibility may drop into MVFR conditions
in the rain, but the stiff southeasterly winds should help limit
the conditions to MVFR. As the rain ends Saturday morning and
winds shift more southerly, MVFR ceilings may persist well into
the day due to the more moist Cook Inlet air and more stable lower
levels of the atmosphere.

&&


$$