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FXAK68 PAFC 080051
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
451 PM AKDT Mon Sep 7 2026

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3)...

Continued wet and windy pattern over Southcentral is expected
through the early portion of this week as a series of upper-level
lows traverse Southern Alaska from Southwest to Southcentral.
Synoptically, the pattern will be wet and windy through early
Wednesday as the pattern evolves, with many localized effects
expected. Through this afternoon, expect chance rainfall over
inland, downsloped favored areas to fill in with rain into the
evening. Rainfall from the Susitna Valley to the northern Gulf of
Alaska coastline will increase from a light rainfall this evening
to a moderate-to-heavy rainfall rate early Tuesday morning,
becoming relatively lighter again later Tuesday morning. Expect
rainfall to persist over Southcentral through Tuesday, diminishing
by Wednesday morning.

With regards to winds, expect gusty winds along the south-and-
western portion of Anchorage tonight, as winds through the
Turnagain Arm increase, and decrease through Tuesday morning.
Similarly, this evening through Tuesday morning, gusty southerly
winds through the Copper River will pick up, with peak winds
reaching 20-25 mph, helping keep the Basin relatively drier than
the rest of Southcentral. By Tuesday afternoon, westerly winds
will increase into Kachemak Bay, rising the sea- state in the
Outer Bay. This does not coincide with a high tide cycle so
significant coastal erosion impacts are not expected.

As the upper-low transits overhead Tuesday, there is the chance
for isolated elevated thunderstorms in the Copper River Basin area
and surrounding mountains, stay tuned. Outflow gap winds out of
Seward and Whittier are expected to pick up Wednesday morning,
with gusts to 35 mph possible, peaking Wednesday afternoon.

-CL

&&


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

Key Messages:

* Showery and breezy through Tuesday night. A building ridge will
  bring benign weather (but increasing fog chances) on Wednesday,
  then a potent front gradually tracks eastward across the Bering
  through Thursday.

* We continue to monitor the potential for minor flooding and
  coastal erosion in Kuskokwim Delta and along Kuskokwim River for
  Thursday and Friday.

Discussion:

Currently, the upper level pattern features a longwave trough
extending across much of the Bering Sea and into Southwest Alaska.
An upper low is located at the base of the trough near the
Pribilof Islands, with several robust shortwaves also transiting
along the upper low`s periphery. As this feature moves east,
expect winds gusting as high as 30-35 mph along the Aleutian
Islands and Alaska Peninsula tonight into tomorrow morning. Rain
showers will also accompany this low, with the heaviest rain
amounts expected in the Southwest interior tonight as an incoming
shortwave helps enhance precipitation along the front. The cold
air and vorticity associated with this upper low could bring a
slight chance of thunderstorms to parts of Southwest Alaska, but
this is looking less likely given the lack of surface heating
associated with the early-morning passage of the low tomorrow.

Ridging builds in behind the upper low for Wednesday, and will be
one of the key influences on how stormy the weather will be across
the Bering and Southwest Alaska in the coming days. A Kamchatka
low will push its front into the Western Bering (along the western
periphery of the ridge) beginning Wednesday afternoon. Models have
generally been trending towards a more resistant ridge, one that
will be strong enough to keep the worst winds in the Western
Bering and perhaps only clipping the northern parts of Kuskokwim
Delta. With the ridge trending stronger and the front continually
being displaced north and westwards, concern for coastal erosion
and flooding for Kuskokwim Delta is diminishing. Still, we
continue to closely monitor the behavior of this front and its
ridge. Though the storm will be weaker in this area and tides will
generally be decreasing around this time, the other factor to
consider will be an influx of water down Kuskokwim River due to
recent rainfall, which may still cause flooding issues along
Kuskokwim River itself, and especially near where the mouth of the
river opens out into Kuskokwim Bay. Stay tuned.

-KC

&&


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

A highly amplified pattern is expected through the second half of
the week as a deep upper level Kamchatka low opens into a trough
in the western Bering while a strong upper ridge slides east
across the Mainland Friday through Saturday. Models remain
consistent on the overall upper level longwave pattern with the
biggest uncertainty continuing to be the exact timing and
placement of individual shortwaves embedded within the mid to
upper level flow. The strong surface low over eastern Russia
continues to trend farther north and west, with ensemble model
guidance steady in the general northeastward track across far
eastern Siberia and into the Arctic Ocean Friday into Saturday.
Confidence remains high on its associated gale- force front
tracking east across the Bering through mid to late this week,
bringing gusty southwesterly winds and moderate to heavy rainfall
across the Aleutians and Pribilof Islands.

The strong front similarly continues to trend farther north in
the Bering as its eastward progression stalls against the strong
high pressure stretching across the North Pacific into the
southern Mainland. The longest duration and strongest core of
winds with this system is now expected to affect the Norton Sound
and Seward Peninsula region through Friday. Despite this shift in
the storm track, a period of gusty small-craft to potentially
gale-force winds along the front is still likely to impact the
Kuskokwim Delta coast by Thursday night through Friday evening.
The long fetch of strong, southwesterly onshore winds could bring
the possibility of high surf and minor coastal flooding and
erosion along the Kuskokwim Delta coast as the front progresses
through the region. Elevated water levels in the Lower Kuskokwim
River due to preceding rainfall across the Interior, combined with
additional rainfall, could lead to minor river flooding for
communities along the river from Bethel to the Kuskokwim Bay.
Details will continue to become clearer in the coming days on the
exact timing and potential impacts of this upcoming late-week
storm.

Behind this system, weaker west-southwesterly flow continues over
the Bering and Southwest Alaska through the weekend, while the
weakening frontal system and rainfall continues east into
Southcentral and the Gulf. Broad troughing remains centered over
the Bering, with models hinting at the pattern becoming more
amplified once again as a low lifts north out of the North Pacific
early next week.

&&


.AVIATION...

PANC...Ceilings will waiver between VFR and MVFR with periods of
light rain through the rest of today. Steadier rainfall arrives
tonight through Tuesday, bringing ceilings down to MVFR with
periods of IFR. Winds become southeasterly with gusts of 20 to 30
knots tonight through Tuesday afternoon.

&&


$$