595
FXAK68 PAFC 220030
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
430 PM AKDT Thu Aug 21 2025

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

Isolated to scattered showers linger over the Southcentral
Mainland through tonight. Otherwise, leaning warmer and drier as
higher pressure builds in through the weekend. The clearest skies
are expected Friday, after which higher clouds will likely build
back in as several fronts graze the Alaska Range. Overall forecast
confidence is high for mostly benign weather across the entirety
of Southcentral Alaska. Forecast confidence is lower in the finer
details like: (1) exact placement of hit-or-miss showers tonight,
(2) the potential for fog along Kodiak Island and Prince William
Sound tomorrow morning, (3) the timing and strength of localized
gusty winds through Anchorage and Copper River Valley, and (4) the
timing of rainfall as a stronger front pushes across the Alaska
Range and into Southcentral later on Sunday. With all that said,
make sure to get out and enjoy these warmer and drier summer days
before the weather pivots back to the cooler and rainier
conditions typical of late August.

-Chen

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
Days 1 to 3: (Today through Sunday afternoon)...

This afternoon, a 500 mb shortwave trough is moving south of the
Pribilof Islands, which is giving a round of rainfall to the
Central Aleutians. Isolated lightning strikes have been recorded
on the Bering Sea side of the Aleutians, in particular north of
Atka and Nikolski due to upper level forcing and elevated
instability. This feature will be short lived as it will quickly
move downstream in the broad, meridional flow situated across much
of the Bering Sea. In Southwest Alaska, weak upper level
troughing has replaced upper level ridging, which has allowed for
a few showers to form around the Bethel area. Elsewhere across the
Southwest, weather is mostly quiet.

Looking westward, a vertically stacked gale-force Kamchatka low
and its front clips the Western Aleutians Friday morning and moves
northeastward by Friday afternoon. The overall synoptic pattern
becomes amplified Friday as upper level high pressure becomes
situated from southwest to northeast across the Aleutians, and the
upper level trough component of the Kamchatka low digs southward
closer to the Western Aleutians. In response, sub-tropical
moisture is advected northward Friday afternoon. An atmospheric
river develops Friday afternoon across the Western Aleutians and
slowly works eastward with time. If current guidance holds,
moderate rainfall moves over the Rat Islands Saturday afternoon
and eastward to Amchitka, Adak, and the Pribilof Islands Sunday
morning.

By late Sunday into Monday, this band of precipitation moves into
the northern most areas of the Kuskokwim Delta coastline.
Rainfall expands in coverage as a wave of low pressure forms along
the moisture axis as it aligns under an area of divergence within
a positively tilted upper level longwave trough. Stay tuned for
updates as the pattern still looks rather wet and windy for some
heading into the work week.

-AM

&&

.LONG TERM FORECAST (Sunday through Thursday)...

The long term forecast remains largely on track with the main
weather concern centered around a soggy weather pattern for the
Aleutians, Bering Sea, and portions of the Mainland. High pressure
will continue to flatten through this weekend as it stretches
across the Alaska Peninsula, southern Bristol Bay and the
Southcentral Gulf Coast. A low continues to linger over the North
Pacific, south of the Gulf of Alaska. These features will
gradually sink southward as a series of frontal passages track
across the Bering Sea while its parent low skims the coast of
Russia. The area of lowest confidence during this timeframe will
be from Kodiak Island through at least the Cook Inlet and Susitna
Valley region.

For Southcentral and Kodiak Island, showers will be likely,
especially over higher elevations, but confidence with winds and
precipitation is much lower throughout the extended forecast due
to stay power of the ridge breaking down and differences in the
models with how they resolve the frontal passages off the
neighboring lows that intrude into the area. Expect the
Southcentral forecast for next week to change with time.

Looking farther west, deep southwest flow with an amble moisture
fetch looks to direct much of its energy over the Aleutians and
across the Bering Sea Monday. Through midweek, models point toward
not only a soggy weather pattern with moderate to heavy rainfall
at times, but also gusty south to southwesterly winds. Gap winds
will be possible along the Alaska Peninsula and across the western
Capes and Southwest Alaska Coast. The potential for coastal
flooding along the Southwest coast looks like less of a threat
compared to yesterdays model runs, but this will continue to be
evaluated in the coming days since subtle changes can still make a
difference in the outcome. There are also some differences in the
surface features of the models in the extended forecast that
would play a role in the temporal and spatial precipitation
outcomes. None-the-less, the Bering Sea, Aleutians, and Southwest
Alaska can expect sogginess. A brief ridge looks to move through
the Western and Central Aleutians late Wednesday with another low
looking to approach the western Aleutians Thursday.

rux

&&

.AVIATION...

PANC...VFR conditions are expected to prevail through this
afternoon and evening along with light northwesterly winds turning
more southerly by late evening. Vicinity showers and brief
periods of MVFR ceilings cannot be ruled out later this evening
through the overnight hours.


&&


$$