649
FXAK68 PAFC 041257
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
457 AM AKDT Mon Aug 4 2025

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

Satellite imagery this morning shows a pair of shortwave trough to
the southeast and northwest of Southcentral, respectively. Between
the two, an upper-level ridge of high pressure is building over
the region. The result is partly cloudy to mostly clear skies for
much of the area, with the biggest challenge in the short term
being the expanse of low-level clouds across coastal and valley
locations this morning.

The shortwave trough over the Interior will move across the
northwestern portion of the Copper River Basin this afternoon as
the upper-level ridge continues to build eastward. This trough
will likely bring another round of isolated to scattered showers
to the higher elevations surrounding the Copper River Basin. A
weaker trough will trail the second, moving east along the Alaska
Range for Tuesday. This feature will allow diurnally driven
convection in the form of isolated to scattered showers over the
higher terrain of the eastern Copper River Basin.

With mainly clear and dry conditions, will continue over interior
Southcentral with daytime highs climbing well into the 70s by
Wednesday. Temperatures will be cooler along the coast with gusty
afternoon sea breezes.

The next big weather-maker comes on Wednesday when a former
Pacific tropical system combines with a system moving south in the
Bering. The surface low consolidates in the North Pacific just
south and between the Eastern Aleutians and southern Alaska
Peninsula Wednesday morning. The front will lift into the Gulf and
across Kodiak Island all day Wednesday before reaching the
southern Kenai Peninsula Wednesday evening. With previous
connections to the tropics, this system looks particularly wet;
especially for Kodiak Island where 1.5 to 2.5 inches of rain is
not out of the question from Wednesday morning through Thursday
morning. In addition to the steady rainfall, widespread easterly
gales are expected along the front as it lifts north through
Wednesday. Storm-force gusts are also possible across the Barren
Islands by Thursday morning.

&&

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

A broad low centered west of the Pribilof Islands encompasses
much of the Bering Sea, with a front extending over the eastern
Bering Sea to the southern Alaska Peninsula this morning. The
front pushes up the peninsula to the Southwest coast today,
bringing light rain and increasing southeasterly winds. Inland
areas remain sunnier and warmer today, with high temperatures near
70 for the Lower Kuskokwim Valley. Cloud cover increases as the
front weakens and moves inland tonight into Tuesday. Despite the
weakening front, the low draws up a continuous stream of moisture
into the eastern Aleutians/Bering Sea and Alaska Peninsula which
continues showery conditions and gusty southeasterly gap winds
through Tuesday. Aside from upslope areas of the Kilbuck and
Ahklun Mountains, inland portions of Southwest see little to no
precipitation from the front.

Meanwhile, Tropical Storm Krosa, located approximately 500
nautical miles south of Attu Island, completes extratropical
transition today as it traverses south of the Aleutian Islands.
The remnant low gets drawn up into the circulation of the broad
Bering system, injecting a new impulse of energy and ample
tropical moisture which brings heavy rain to the south side of
the Alaska Peninsula beginning Tuesday evening. Between 2 and 4
inches of rain are possible through Wednesday for the communities
of Perryville and Chignik before the low and its front lift
north toward Kodiak Island and mainland Southwest Alaska. Gale
force winds are also forecast to blow across the northern Alaska
Peninsula into Bristol Bay as the remnants of Krosa merge with the
pre-existing Bering Sea low. Another hazard possible with the
remnants of Krosa is increased instability leading to marine
thunderstorms south of, and potentially moving over the Alaska
Peninsula on Wednesday.

Wednesday night into Thursday, rain pushes up into mainland Southwest
Alaska, though it will not be quite as heavy as along the Alaska
Peninsula. Gusty winds out of Kamishak Gap will also accompany the
lifting front. All in all, expect a trend toward wetter and cooler
conditions toward the end of the week for Southwest Alaska.

&&


.LONG TERM FORECAST (Days 4 through 7 Thursday through
Sunday...

Synoptic model agreement is reasonably high through around
Friday. Southcentral Alaska transitions to a breakdown in the
ridge while a dying tropical disturbance tracking along the
Aleutians merges with the Bering Sea low and dips across the
central and eastern Aleutians around midweek. For the last half of
this week, the associated front will bring ample moisture with
periods of moderate to potentially heavy rain to the Alaska
Peninsula and Kodiak Island. Given the size of the Bering low,
showers will be likely across the central and eastern Aleutians
and steadier periods of rainfall feed up across Southwest Alaska.
The front is expected to weaken as it lifts toward the northern
Gulf and the supporting jet continues eastward toward the
Southeastern Panhandle for the weekend. With southerly flow
prevailing for Southcentral, expect varying degrees of gusty winds
along the Gulf coast including the terrain gaps and soaking rain
predominantly along the coast and Prince William Sound. Models
diverge with the position of the low center toward the weekend
timeframe and the overall pattern becomes more dependent upon its
interaction with a trough over northwestern mainland Alaska.

Rux

&&.AVIATION...

PANC...VFR conditions and light winds are expected through the TAF
period. Winds will flip to northwesterly this afternoon becoming
westerly this evening.


&&


$$