712
FXAK68 PAFC 021256
AFDAFC

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

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Monday evening)...

Widespread rain continues to fall this morning from the western
half of the Copper River Basin south and west across the Susitna
Valley and south to the Kenai Peninsula. Over the past 12 hours,
0.50" to 1.00" of rain has already fallen across much of the
Copper River Basin into western Prince William Sound with lesser
amounts, ranging from a few hundredths of an inch to around 0.25"
of an inch for the Mat-Su Valleys south to the Northern Kenai
Peninsula. Gap winds also continue ahead of the trough responsible
for the widespread rainfall, although wind speeds are continuing
the downward trend from overnight peaks.

Key hazards to watch for will be:

* Flood Watch remains in effect for Western Copper River Basin,
  Sutton, and portions of Mat Valley this morning through Monday
  afternoon, due to heavy rainfall.

The potent upper-level trough responsible for the widespread
moderate to heavy rain across the central portion of the
Southcentral Alaska overnight will continue to slowly slide
westward this morning before stalling and shearing apart over
Cook Inlet this afternoon. The result will be rain continuing for
the western half of Southcentral, with the precipitation becoming
more scattered and showery in nature from the Kenai Peninsula
north to the Susitna Valley by this afternoon. A storm total of
1.50" to 2.00" of rain is still possible from Sutton into the
western Copper River Basin.

A secondary wave will move north from Yakutat to around Tok this
afternoon, as it does, the flow in the mid- and upper-levels will
shift, allowing moisture and precipitation to advect
northwestward, toward the trough. This will keep precipitation
lingering across the northern Copper River Basin ans Susitna
Valley into Sunday. A few isolated thunderstorms may be possible
near the Nabesna Road today and along the Denali Highway Sunday.

By Sunday afternoon, there is considerable difference in the
guidance as to the track of that secondary upper-level trough.
The GEM and GFS drive this feature south through the Copper River
Basin by Sunday afternoon while the NAM, as well as other hi-res
guidance, keep this feature north of the Alaska Range until Monday
morning before it finally moves south. The timing and track of
the feature will dictate the timing and locations of showers and
thunderstorms through the Copper River Basin.

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.

-KC/TM

&&


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

Currently, mostly clear skies and calm winds are present in much
of the Southwest Alaska mainland due to slack flow that is
present. The Bering is much more active with a large low bringing
precipitation and gusty small craft winds across the Aleutians
and Pribilof Islands. Gap areas in the Eastern Aleutians and
Alaska Peninsula are gusting up to gale force. Winds will slowly
weaken in the Bering as Saturday progresses, but gap areas will
retain small craft winds. There is a chance of isolated
thunderstorms stretching from Aniak north to the Alaska Range in
the Lower Kuskokwim Valley. By this (Saturday) afternoon, a front
will push onshore and bring rainfall along the coast of the
Southwest mainland. The rain will reach Bethel and Dillingham by
Saturday night/early Sunday morning. Breezy southeast winds will
also accompany the front.

Sunday is similar to Saturday due to the low stalling out in the
Bering. The low will meander in place through the forecast
period. There will be a few differences such as higher
cloud cover, cooler temperatures, and lower chances for
thunderstorms for inland areas of the Southwest mainland. The
Bering is also largely the same, but another front will bring
moderate to heavy rainfall to the Pribilof Islands and the Eastern
Aleutians by Sunday afternoon. The front will push inland on
Monday, giving the coastal regions more rainfall. The front will
stall out on the coast, so inland areas will be drier. Breezy
southeast winds will also affect the coastal areas as the front
moves onshore. Meanwhile, the Bering will still be in the same
regime on Monday, with multiple waves bringing periods of rainfall
to the Aleutians and Pribilof Islands. Looking a bit ahead to
Tuesday and Wednesday reveals the low starting to drift south.
This will likely bring another bout of heavy rainfall and gusty
winds to the Aleutian Islands.

-JAR

&&


.LONG TERM FORECAST (Days 4 through 7 Tuesday through
Friday...

The main features in the day 4 through 7 time frame are a low
pressure system exiting the Gulf, and a broad upper level low
moving generally southeast from the Bering Sea across the Aleutian
Chain. As with any low, there will be embedded impulses of energy
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. Otherwise, seasonal temps with generally rain-free
conditions are expected.


&&

.AVIATION...

PANC...A trough moving through the area will bring rainfall
to the terminal through Saturday morning. Expect mainly MVFR
ceilings this morning, although any heavier rainfall could drop
ceilings and/or vis briefly to VFR. Ceilings should slowly improve
to VFR by late morning as the steady rain becomes more scattered
and showery. Showers are expected to taper off by mid to late
afternoon. Gusty southeasterly winds this morning will also slowly
diminish through mid afternoon, quickly becoming light and
variable by Saturday evening. With lingering low-level moisture
and light winds, patchy fog is possible overnight into early
Sunday morning.

&&


$$