Gale Warning 537, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
446 PM AKDT Thu Sep 24 2026

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

Key Message:

- Gap winds return to Southcentral ahead of a gale force front
  that will lift northeastward across the northern Gulf through
  the short term period.

Discussion:

A broad surface trough draped northwestward from a weakening low
pressure system located in the eastern Gulf is sending waves of
rainfall towards the Prince William Sound. Aside from that, a gale
force front extending from a very strong Bering low with a
corridor of moderate to heavy rainfall is entering the western
Gulf this afternoon and will move across Kodiak Island through
Friday morning before moving northeastward towards coastal
Southcentral.

Coastal ridging is on track to build ahead of the front across
the northern Gulf coast, which will lead to increasing gap winds
for the Copper River Basin, Knik River Valley, and Turnagain Arm
as pressure gradients tighten. The Knik River Valley wind is the
area of the biggest uncertainty Friday afternoon as there is a
chance that a few elevated wind gusts move into Palmer, but some
models show that the strong down-inlet component to the wind
prevailing and essentially bending the wind direction southward
before making it into the Matanuska Valley. Due to the parent low
location out west signaling down-inlet flow, the Anchorage Bowl
seems to be less of a concern than the Hillside, where at
elevation wind gusts will be ticking up to 50 mph. Overall
consensus remains short of Wind Advisory criteria for the
Hillside. Current forecast confidence is still in the medium range
(50 to 60 percent) for Hillside wind gusts. Higher profile
vehicles may struggle with those gusty winds on the Seward Highway
along the Turnagain Arm, especially Friday afternoon into
Saturday morning as the highway could become clipped with strong
wind gusts - though the strongest core of winds will remain
located over the Arm. The low location out west will be a key
factor in determining the extent of impacts from the Turnagain Arm
winds, and there is no real indication in the models of the
Bering low driving north of 60N, where in doing so would bend
winds more into west Anchorage, but that chance right now is low
(20%). Stay tuned.

Through the short term, periods of locally heavy rain are
expected with strong orographic lift along the eastern Kenai
Peninsula. By Sunday morning, Seward, Cordova, Valdez, and the
eastern portions of Turnagain Arm are on track to see 1 to 3
inches of rainfall. In contrast to coastal locations,
southeasterly winds ahead of the front will create a "rain shadow"
effect in lee of the mountains for the western Kenai Peninsula,
Anchorage Bowl, the MatSu, and Copper River Basin, keeping these
areas mostly dry through Saturday morning. As the front continues
north, however, some of the energy could push moisture northward
up the Cook Inlet, bringing very light rainfall to Kenai,
Anchorage, and the MatSu Saturday afternoon. The pressure gradient
will show signs of gradual relaxing Saturday night into Sunday,
but strong winds will continue to push east to southeast winds
into Prince William Sound.

-AM/Rux

&&

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

Key Messages:

* A strong Bering Sea low to impact the Bering Sea, Aleutian and
  Pribilof Islands, and Southwest Alaska through Saturday.

* For the Bering Sea: Widespread areas of gale force winds, some
  areas of sustained storm force winds with hurricane force gusts
  expected through the Western and Central Aleutians including
  near Adak/Atka and Shemya where High Wind Warnings are in
  effect. A High Wind Warning is in effect for Unalaska for gusts
  up to 55 mph late Thursday and Friday. After a lull, expect
  another stronger push of westerly winds with gusts to 60 mph
  late Friday. Expect elevated wave heights, with seas up to 25
  to 35 ft possible.

* For Southwest Alaska: High Wind Warnings are in effect for
  Coastal Kuskokwim Delta, the Western Capes, and northern Bristol
  Bay coast. The Coastal Flood Warning remains in effect with the
  primary communities of concern being Kwigillingok/Kongiganak and
  Kipnuk, and communities near and along the mouth of the
  Kuskokwim River. As well as a Flood Watch remaining in effect
  for the interior Kuskokwim Delta, for areas near Bethel.

Discussion:

A very strong low pressure system centered over the southwestern
Bering Sea continues to dominate the pattern, with a strong front
now advancing inland across the Southwestern Alaska coastline.
Embedded in the front, a potent low pressure spin-up developed
this morning, leading to areas of very strong winds across
portions of the Eastern Aleutians and Alaska Peninsula. The strong
parental low is poised to continue operating in the mid-960
millibars as lobes of energy continue to merge with the system's
upper-levels. The core of the strongest winds began to track from
west to east across the Aleutian Chain this morning, moving
through Shemya and Adak, and will extend to Unalaska through this
evening.

The High Wind Warnings covering much of the Aleutians including
Adak/Atka to Unalaska, focus on two pulses of strong westerly
winds across the area. The first of which will come this evening,
with widespread areas of sustained storm-force winds near Adak to
Nikolski. By Friday morning, the area will see a reprieve in the
strong winds until late Friday afternoon. The second pulse will
come Friday evening as another upper- level system will drop in,
reinvigorating the winds across the area from Adak to Unalaska,
with the winds in Unalaska looking potentially stronger than the
first pulse. This second round of winds looks to diminish through
Saturday.

For Southwest Alaska, the storm to gale-force front is moving
inland across the coastline tonight. High Wind Warnings are in
effect for much of the western-facing coastlines of Southwest
Alaska through this evening as the front moves through. Given the
strong push of onshore flow, the Coastal Flood Warning remains in
effect until Saturday morning for the Kuskokwim Delta coast.
Models continue to struggle to come to a consensus on the precise
track of the low as it nears the YK- Delta through Friday and the
timing for which it begins to move inland and weaken. Despite the
uncertainty, there is enough confidence to say that elevated water
levels across portions of the Kuskokwim Delta coastline are
expected. Water levels on average of 1.5 to 2.5 feet above the
normal highest tide line are expected in Kwigillingok for
Thursday, with the worst case scenario water levels at 5 feet
above the normal highest tide line. Water levels 1.5 to 2.5 feet
above the normal highest tide line are expected in Kipnuk for
Friday, with the worst case scenario water levels at 2 to 3 feet
above the normal highest tide line.

The low is generally expected to move inland and weaken through
Saturday, with the remaining westerly small craft winds across
the southern Bering and Bristol Bay, eastern Aleutians, and
Alaska Peninsula to weaken from west to east through Saturday
evening. Showery and relatively calmer weather will linger across
the Southwest Mainland through the weekend.

-CL

&&

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

The long term begins late Monday with the longwave trough axis
moving east and extending from the Al-Can border south to the
eastern Gulf of Alaska. The result is low pressure over the Gulf
with showers and winds wrapping around the low and across the
immediate Southcentral coast. This feature will continue to move
east toward the Alaska Panhandle for Tuesday, with northwesterly
flow aloft and at the surface in the wake of the low and the
upper-level trough. The northwesterly flow will advect weaker
waves from northwest Alaska across interior Southwest and
Southcentral, allowing for periods of rain showers and higher
elevations snow showers along the mountains and across the Copper
River Basin Tuesday into Wednesday. Northwesterly gap winds will
also pick up along the coast across the Barren Islands through
this same time period. A stronger upper-level shortwave deepens
into an upper-level low as it drives across the Southern Mainland
for Thursday keeping showers, gap winds, and colder air in place.

Farther west, strong northwesterly flow over the eastern Bering
and AKPen weakens as the aforementioned waves move east. A ridge
of high pressure settles over the western Bering and Aleutians
Monday and moves east through Tuesday as a Kamchatka Low moves
toward the forecast area with a gale-force front swinging out
ahead of it. The front reaches the western Aleutians by late
Tuesday moving to the eastern Aleutians by late Wednesday. Model
agreement then wanes with respect to how quickly this front and
its parent low move east across the Bering and Aleutians.
Whatever the solution, conditions for these areas look to remain
unsettled with steady rain and wind through much of the latter
half of next week.

-TM

&&

.AVIATION...

PANC...VFR conditions will persist through the TAF period,
although increasing mid and high level clouds are expected. Light
and variable winds early may shift and become southeasterly for
a time later this evening. Any period of Turnagain Arm winds
clipping the terminal later this evening should end as winds bend
back down Cook Inlet for Friday morning. This shift in wind at the
surface will be met with a continued southeasterly winds aloft
resulting in an extended period of LLWS at the terminal for
Friday.

-TM

&&