Gale Warning 497, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
420 PM AKDT Tue Sep 1 2026

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

Key Messages:

- Another cold night is expected again Wed morning, especially for
  coldest prone locations (Butte, Muldoon, Campbell Tract, and the
  Eagle River Valley) with temperatures approaching freezing.
  Temperatures will depend on cloud cover. The main concern is for
  cold and frost sensitive outdoor plants/vegetation. A trend
  toward seasonable temperatures is expected for the last half of
  the week.

- Gusty offshore winds continue over the next few days with the
  strongest winds along the coast and through gaps and passes.

- Weather pattern turns more active heading into the weekend.

Discussion:

Isolated pockets of cold temperatures were observed this morning
for coldest prone locations in the western Kenai Peninsula,
Anchorage, and Matanuska Valley. The frost advisory will remain in
effect until 9AM AKDT Wednesday. Frost and colder than normal
temperatures will continue to be a concern for sensitive outdoor
plants. Protect, move, or cover those plants for an additional
morning should skies be clear during the coldest part of the
morning. Frost potential will depend on cloud cover. Trends today
are for more clear conditions and less in the way of clouds
tonight and Wednesday morning. Temperatures look to trend to more
seasonable ranges Thursday onward as a ridge will start to build
and high clouds start to filter across Southcentral.

Gap winds, especially through Whittier and Seward, will remain
elevated for the next few days as flow will remain out of the
northwest. Gusts may relent somewhat this late afternoon to early
evening near Seward as the low in the eastern Gulf moves onto the
North Pacific and higher pressure builds across the area. Gusty
conditions redevelop later this evening as an upper-level
shortwave approaches the area from the northwest.

For Wednesday, the shortwave, mentioned above, digs south from
Central Alaska to northeastern portions of the Copper River Basin.
Trends today have this feature digging a little farther south and
have the features a little sharper/stronger than at this time
yesterday. Thus, light precipitation in the form of some snow
showers will be likely late tonight into Wednesday morning across
northeastern portions of the Copper River Basin; namely Paxson and
Mentasta Pass/Lake. Eureka could also see some very light snow
out of this as well. As temperatures warm later Wednesday morning,
any leftover precipitation will change over to rain before ending
Wednesday afternoon.

A ridge from the Bering Sea and over Southwest Alaska will move
east and over Southcentral Alaska for Thursday. This will result
in another nice day across the area. The ridge will continue to
shift east and propagate into Yukon, Canada Thursday and Friday.
This will the open the door for southerly to south-southwesterly
flow aloft through Friday. At this time, the ridge is trending a
little stronger, despite its slight eastward jog. Most of the
precipitation associated with a low in the Bering will remain
confined across Southwest Alaska through Friday. Therefore, the
timing for when rain makes it into Southcentral has been pushed
back to Friday night into Saturday morning as opposed to an
earlier rain arrival Friday afternoon. The weather pattern past
Friday looks unsettled and wet. Enjoy the nice couple of days
ahead before the weather pattern turns more active heading into
the weekend and beyond!

&&

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

The current synoptic setup has been relatively unchanged over the
last 24 hours. A vertically stacked ridge remains anchored over
the North Pacific, Aleutians, and southern Bering (from about
Saint Paul and southward). Underneath the ridge, there are areas
of low stratus and fog moving across the region. Outside of fog
and low stratus, the Central and Eastern Aleutians have warmed
quite substantially today with Unalaska reaching the low 70s.
Current satellite imagery depicts cloud cover stretching from the
Western Aleutians to just north of Saint Paul to the Southwest
coast and Alaska Peninsula, which is rounding the northern extent
of the ridge. Radar returns show showers moving southeastward and
mainly just offshore of the Southwest Alaska coastline and then
moving across the Alaska Peninsula.

With an incoming low pressure system arriving to the Western
Aleutians tonight, this will help nudge the ridging eastward and
make way for a gale force front to traverse the Aleutians through
Thursday. Alongside the wind, there is robust moisture transport
from the tropical and sub-tropical Pacific that will result in a
corridor of moderate rainfall along and just ahead of the front.
While the parent area of low pressure stays quasi-stationary
through late Wednesday, its front arrives to the Central Aleutians
with gales and rainfall. One area in particular to watch will be
Cold Bay, where a southeasterly wind direction ahead of the strong
front will greatly enhance wind speeds through the southeast to
northwest oriented gap there. The GFS/NAM MOS guidance generally
under-do these winds because of their coarseness, but are still
reading out sustained winds near 40 knots Thursday morning. Using
this as a "floor" for wind speeds for Cold Bay, it is quite
possible that this location could be approaching high wind
criteria Thursday morning. Stay tuned.

On the other hand, the front ever so slightly weakens to a high
end small craft front with gusts to gale force later Thursday
morning as it closes in on Southwest Alaska, and in particular,
the Kuskokwim Bay region. This raises another concern as a
somewhat lengthy fetch of strong southerly winds blows towards the
Kuskokwim Delta Coast. Areas of the coastline that are
perpendicular to the southerly wind direction, such as
Kwigillingok, have the best chance to seeing impacts with this
front, with current P-ETSS guidance showing water levels reaching
anywhere from 1 to 1.5 feet above the normal highest tide line.
While actual coastal flooding is of low concern at this time, the
focus and messaging with this system is coastal erosion coupled
with high surf potential. Strong southerly winds will continue
through Thursday afternoon and evening and finally start to
decrease early Friday morning. A round of rainfall will accompany
the arrival of this front, with much of the Kuskokwim Coast and
Delta on track to see up to 0.5 inch of rainfall, with higher
amounts farther south along the Western Capes. Stay tuned for
updates for this area as well.

-AM

&&

.LONG TERM FORECAST (Days 4 through 7: Saturday through
Tuesday)...

The long-term forecast looks on track, as an active pattern
persists across the Southern Mainland, Bering Sean, and Aleutian
Chain due to a ridge axis sliding east over the Alaska Panhandle,
and a complex low pressure system spinning about in the central
Bering Sea.

Across Southcentral Alaska, the aforementioned ridge will move
east to the Alaska Panhandle with relatively quiet weather
holding on for eastern Prince William Sound and the Copper River
Valley to start the weekend. As the ridge moves east, it will
open the door to southwest flow aloft. Steady rain from Southwest
will move into Southcentral from west to east through Saturday as
a plethora of shortwaves lift up and over the area from North
Pacific and Gulf. Showers continue over Southwest, the Aleutian
Chain, and Southcentral for Saturday as a broad upper-level
trough remains in the Bering and southwest flow aloft remains
across Southcentral.

A series of several shortwaves spinning around the complex low in
the Bering will move from the Bering into Southwest Alaska through
Saturday. By late Saturday into Sunday morning, a compact low
moving east across the North Pacific will swing northward,
lifting toward the Alaska Peninsula. Model agreement is poor
regarding the progression of this feature, and how it may interact
with other shortwaves embedded in the flow aloft and propagating
northward. However, there is some agreement that this feature may
maintain its strength as it lifts north with gusty easterly winds
and area of heavy rain for the Alaska Peninsula and Bristol Bay
areas as well as Kodiak Island and the northern Gulf and
Southcentral coast late Sunday through late Monday. Stay tuned.

-TM

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

-TM

&&