742
FXAK68 PAFC 071308
AFDAFC

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

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

Unsettled wet pattern continues across Southcentral as two upper
level waves anchored to a low in the Bering Sea move through
southern Alaska. The first wave moved into Southcentral overnight,
bringing widespread rain. The front weakens slowly and spends
today exiting to the northeast. Southerly winds through the Copper
River will pick up later this morning and persist through Tuesday
morning. Peak winds around 20-25 mph are expected through the
Copper River this evening, and will aid in keeping the lower
elevations of the Copper River Basin drier. Light rain will move
in as winds come down.

The second system is stronger in general and has a surface low
centered in the Bering Sea. This surface low will also weaken
some as it tracks eastwards and moves onshore in the Kuskokwim
Delta , but the upper level wave will track over Southcentral
Alaska late tonight. The associated upper level trough will
continue working its way eastward across Southcentral through
Tuesday, keeping precipitation in place over the region. Turnagain
Arm winds will bend into Anchorage this evening as the trough
approaches, with wind gusts expected to range from 15 to 30 mph.

KM

&&


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

A long-wave trough remains entrenched over the Bering Sea. A
subtropical jet streak of 130kt+ on the leading edge of the
trough extends from southwest to northeast from the north-central
Pacific to the Aleutians and southeastern Bering Sea. No surprise,
the current storm track is right along this general corridor.

The first storm which tracked along the Aleutians, Alaska
Peninsula (AKPen) and Bristol Bay yesterday is now lifting north
across Southwest Alaska as a weak low. A negatively tilted upper
level short-wave trough continues to lift northeastward toward
Southwest AK, with showers and cool temperatures seen throughout
the region. Isolated to scattered showers will continue throughout
the day as the low continues northward and multiple shortwaves
traverse over the region. Cloud cover remains, leading to a
relatively cool day for much of Southwest Alaska as temperatures
likely peak in the mid 50s. For portions of the northern AKPen,
downsloping winds off the mountains likely bump high temperatures
up to the upper 50s to low 60s today.

Storm #2 continues to traverse along the Aleutian Chain. The most
impactful weather around this low are small-craft to gale force
winds across the central Aleutians (Adak, Atka, and surrounding
waters). The low will lift north through the Bering today,
bringing light rain and southwesterly to westerly small-craft
force winds to the waters around the Aleutians, AKPen, and in the
eastern Bering. By late this evening, the low will move into
Southwest Alaska and continue to weaken. As the low moves onshore,
additional rain is expected across Southwest and the AKPen.
The heaviest and most persistent rain will be along the western
Alaska Range. With little space between lows, Southwest AK will
remain cool and wet through Tuesday. Though the low moves into
Southcentral by Tuesday morning, rainfall likely persists along
the western Alaska Range down through the AKPen on Tuesday with
westerly winds upsloping into the mountains and the upper level
low passing overhead.

The upper flow de-amplifies and becomes more progressive Monday
night through Tuesday, with the Bering trough exiting to
Southcentral and the Gulf and a ridge building over the Bering
Sea. Aside from lingering showers over Southwest AK and the AKPen,
Tuesday looks like a quiet weather day across the Bering Sea and
Aleutians. With the ridge slowly moving east, Wednesday looks to
be quiet as well for the eastern Aleutians, AKPen, and Southwest
AK. After Tuesday, all eyes shift to a potentially more impactful
storm for later in the week. On Wednesday, a large and deep low
will track near the Kamchatka Peninsula and northeastward toward
the Arctic, sending a strong frontal system eastward into the
western Aleutians and western Bering Sea.

-PA/SEB

&&


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

The upper level pattern becomes increasingly amplified to begin
the long term period as a strong upper level Kamchatka low opens
to a trough in the western Bering while a strengthening upper
ridge slides east across the Mainland. Ensemble model guidance
remains in fairly good agreement for the associated surface low
over Kamchatka to track northeast across far eastern Siberia and
eventually into the Arctic Ocean by Friday. Its associated small-
craft to gale-force front moves east across the Bering through
midweek with gusty southwesterly winds and moderate to heavy
rainfall across the Aleutians and Pribilof Islands.

The front is set to reach the Southwest Alaska coast Thursday
into Friday, spreading the gusty winds and moderate to heavy
rainfall across the western Mainland. 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.
Additionally, widespread moderate to potentially heavy rainfall
across Southwest Alaska will accompany this system as it taps into
a robust stream of subtropical Pacific moisture. Elevated water
levels in the Kuskokwim River due to preceding rainfall across the
Interior, combined with strong southwesterly winds up Kuskokwim
Bay and additional rainfall, could lead to minor river flooding
for communities along the river from Bethel southwards. Details
will continue to become clearer in the coming days on the exact
timing and potential impacts of this upcoming late-week storm.

By the weekend, weaker, more zonal flow takes over the Bering
while the weakening frontal system and rainfall continues east
into Southcentral and the Gulf. Expect unsettled, showery weather
to continue across the Bering, Southwest, and Southcentral through
the weekend into early next week as weak upper level
perturbations move through the region.

&&
.AVIATION...

PANC...Light rainfall with mostly VFR conditions will prevail
through the TAF period. Ceilings are expected to remain near
5000`, with intermittent drops to MVFR (2000` to 3000`) during
steadier rainfall this morning. Winds will remain light through
midday before becoming southeasterly with gusts to 20 to 25 knots
during the early afternoon.

-AM


&&


$$