099
FXAK68 PAFC 030047
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
447 PM AKDT Sat Aug 2 2025

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

A Flood Advisory has been issued for areas along the Matanuska
River as water levels are now forecast to rise into minor flood
stage. Here are the hazards to watch for:

* Flood Advisory along Matanuska River through 6 PM on Sunday
* Flood Watch remains in effect for Western Copper River Basin,
  Sutton, and portions of Mat Valley through Monday afternoon

Few major changes were made to the overnight forecast update, so
the previous forecast discussion still stands, with minor edits:
Over the past 24 hours, 0.50" to 1.50" of rain has fallen across
Matanuska Valley, Copper River Basin, and western Prince William
Sound, with lesser amounts (ranging from a few hundredths of an
inch to around 0.5" of an inch) for Susitna Valley, Anchorage, and
Northern Kenai Peninsula.

The potent upper-level trough responsible for the widespread
moderate to heavy rain across the central portion of Southcentral
Alaska overnight is shearing apart over Cook Inlet this
afternoon. As such, precipitation has become more scattered and
showery in nature from the Kenai Peninsula north to the Susitna
Valley. A storm total of 1.50" to 2.00" of rain is still forecast
from Sutton into the western Copper River Basin.

A secondary wave moving in from Tok will keep precipitation
lingering across the northern Copper River Basin and Susitna
Valley into Sunday. A few isolated thunderstorms are expected
near the Nabesna Road today and along the Denali Highway Sunday,
though marginal storm environment means that there is uncertainty
with where we might see isolated thunderstorms the next couple of
afternoons.

By Monday, the departure of the upper-level trough and building
of a ridge will result in drier and warmer conditions for
Southcentral through midweek.

-TM/KC

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(Days 1 through 3: This afternoon through Tuesday evening)...

Currently, a tightly wound upper-level low moves slowly east
across the Yukon and Kuskokwim Valleys. The bigger and more
notable weather-maker continues to be large vertically stacked
low in the west-central Bering Sea. Its initial front is currently
along the southwest coast and across the southern Alaska
Peninsula (AKPEN).

Southerly flow will persist across Southwest Alaska and the AKPEN
through at least the middle of next week. The main driver of this
southerly flow into the southwest mainland is the very slow
tracking of the west-central Bering low to the south-central
Bering just north of the Central Aleutians by Tuesday evening.
Along with the sustained southerly flow aloft, southeast gap winds
through the AKPEN will also persist through at least the middle of
the week. Upslope precipitation will also be enhanced along the
Pacific side of the southern AKPEN through Tuesday evening.
Locations such as Chignik and Perryville can expect between 1 to 2
inches of rainfall through Tuesday evening as the southerly flow
helps to ring out moisture along the terrain there.

The now central Bering low`s secondary front sweeps eastward from
the Western and Central Aleutians Sunday morning to the Pribilof
Islands and Eastern Aleutians by Sunday afternoon. This secondary
front eventually makes it to the AKPEN Monday morning and to the
southwestern mainland coast by Monday afternoon. Light to moderate
rain will accompany this front from the Aleutians east to
southwestern mainland. The front and its associated rainfall will
linger across the AKPEN and coast through Tuesday afternoon.

An additional shortwave in the North Pacific will lift northward
towards the Eastern Aleutian Chain and southern AKPEN Tuesday. The
associated surface low will also lift towards the Eastern Chain
and southern AKPEN. There are still some questions on the
progression and exact timing and track of this North Pacific low.
However, trends today concerning Tuesday into Wednesday are
wetter for the Eastern Aleutians and wetter as well as windier for
the southern AKPEN. Stay tuned as details are ironed out on this
system.

&&


.LONG TERM FORECAST (Days 4 through 7 Wednesday through Saturday...

The main feature for South Central, Southwest, and the Aleutians
in the day 4 through 7 time frame is a broad upper level low
moving generally easterly along the Aleutian Chain. As with any
low, there will be embedded pockets of vorticity rotating through
the broad cyclonic flow sparking areas of rain. At this point,
the most likely scenario includes periods of showers from the
central and eastern Aleutians to Kodiak through the period. By the
end of the period, showers can be expected all along the Gulf
Coast. Otherwise, seasonal temps with generally rain-free
conditions are expected.


&&

.AVIATION...

PANC...Scattered showers will continue to taper off this
afternoon and evening. VFR and light winds are expected, but with
lingering low-level moisture with light winds, patchy fog is
possible tonight through Sunday morning.

&&


$$