Gale Warning 505, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
405 PM AKDT Mon Sep 8 2025

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

Rain showers continue to decrease as a short lived ridge build
into the area. A low in the Aleutians moves through the Gulf of
Alaska tomorrow and Wednesday bringing rain and strong winds to
Southcentral.

A 976 mb low tracks out of the North Pacific and into the Gulf of
Alaska as a 988 mb low the next 48 hours. Its front brings
southeasterly to easterly winds to Akhiok early Tuesday morning
and later that morning to Kodiak City. Easterly winds ranging from
45 to 55 mph and wave heights from 8 to 12 feet through the
Barren Island Tuesday morning through late evening are expected as
the front pushes northward. Northerly winds through the Cook
Inlet on the western Kenai Peninsula increase Tuesday evening
through Wednesday morning as the front pushes northward. Wind
gusts ranging from 45 to 55 mph and wave heights 8 to 12 feet are
expected. As the front moves northward, easterly wind gusts
through the Turnagain Arm range from 45 to 55 mph Tuesday evening
into late Wednesday morning. A barrier jet forms as strong winds
remain parallel to the northern Gulf of Alaska / Prince William
Sound coastlines with gusts ranging from 50 to 60 mph overnight
Tuesday into Wednesday morning.

Rainfall amounts from Tuesday morning into Wednesday evening in
eastern Kodiak Island and along the Kenai Peninsula coastline
northeastward to Hinchinbrook Island range from 1 to 3 inches;
highest in the western Prince William Sound coastline to eastern
Kenai Peninsula north of Seward. Amounts from an inch to a few
tenths of an inch can be expected at interior locations including
the Copper River Basin, the Mat-Su valleys south to the western
Kenai Peninsula. Tomorrow afternoon and evening are the greatest
chances for rainfall in these locations.

&&

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

A storm-force low is centered about 100 miles southwest of
Nikolski this afternoon. This low, partly associated with former
Tropical Storm Peipah, transported significant tropical moisture
northward, dropping around 2.5 inches of rain in Adak over the
past 24 hours. Additionally, a swath of northerly storm force
winds continue to blow through the central Aleutians, with wind
gusts up to 65 mph recorded today. Out ahead of the low, a high-
end gale force front has produced east to southeasterly wind
gusts of similar intensity through the eastern Aleutians. The low
tracks east along and south of the Aleutians tonight, bringing
continued strong winds. However, the now-occluded low is near peak
intensity and winds will gradually diminish below storm force this
evening. Rainfall, additionally, will diminish in intensity as
the center and occluded front become cut off from the bulk of the
moisture which skirts south across the North Pacific. Isolated
thunderstorm activity wrapping the center of the low ceased
earlier this morning, though there is some potential for renewed
thunderstorm development near the low's triple point as it tracks
south of the Alaska Peninsula tonight in the vicinity of Chirikof
Island. Across Southwest Alaska, fairly isolated showers are
expected to clear out tonight as a ridge out ahead of the low
moves in through midnight.

Beyond that point, however, the low tracks south of the Alaska
Peninsula, spreading its occluded front up into Southwest Alaska
and bringing light to moderate rainfall. Gusty east to
northeasterly winds accompany the arrival of the low for mainland
Southwest Alaska, with wind gusts up to 60 mph concentrated where
winds funnel out of Kamishak Gap, impacting Iliamna and Igiugig
through Tuesday evening. Behind the low, north to northwest winds
will still pack a punch as they are aided by cold air streaming
south across the Bering Sea. Northwesterly gale force winds
advance into the eastern Aleutians on Tuesday and then into the
Alaska Peninsula by Tuesday night. Sustained winds remain well
into gale force range across parts of the eastern Bering and down
into the eastern Aleutians though much of Wednesday before
diminishing.

Late on Wednesday, the low will finally drift off into the Gulf of
Alaska. Rain will gradually end from west to east through
Thursday morning as cooler and drier air begins to spill into
Southwest Alaska along with an Arctic trough digging down into
Western Alaska. Temperatures drop into the 30s for much of the
inland areas on Wednesday night with potential for mostly clear
skies, while coastal portions of Southwest Alaska likely hover
closer to 40. Quieter conditions also return to most of the
Bering Sea and Aleutians for Wednesday as a ridge axis builds into
place behind the exiting low. Heading into Thursday, winds remain
fairly light across most of the Bering Sea as a messy, weak low
enters from the west and leads to periods of rain.

Quesada

&&

.LONG TERM FORECAST (Days 4 through 7 - Friday through Monday)...

Model agreement by Friday is loose, however generally a low is
expected to be situated in the northern Gulf of Alaska bringing
rain to the Southcentral Coastline. Inland precipitation is
expected to be lighter and primarily confined to higher
elevations. Valleys and the lee side of the mountain ranges will
remain mostly dry. Out west, agreement is worse with weak features
moving through the region and models not coming together on
placement or timing, however a generally unsettled pattern due to
the lack of any major features such as a low or ridge.

By Saturday, there is moderate confidence towards a low pressure
system developing in the northern Pacific and advancing towards
the southwestern Gulf of Alaska by late Sunday. Agreement on the
track of this low is poor, with some solutions bringing it up near
the southern Alaska Peninsula and others toward Southeast Alaska.
Either way, this would likely result in easterly flow across the
northern Gulf coast and an increased rain potential early next
week for Southern Alaska.

-CL

&&

.AVIATION...

PANC...VFR conditions are anticipated tonight and through the
start of Tuesday. One concern will be for timing of precipitation,
most likely starting around 21z tomorrow. Increasing
southeasterly flow over the mountains will help keep any
precipitation that does fall relatively light, though ceilings
could dip to MVFR levels. A second concern will be for wind shear,
with a northerly wind at the surface and a strengthening
southeasterly wind above 1000 feet tomorrow afternoon/evening.

BL

&&