Nikiski, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

029
FXAK68 PAFC 260105
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
505 PM AKDT Wed Jun 25 2025

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

Another partly cloudy to mostly cloudy day is in the books for
Southcentral. The culprit, a shortwave trough currently
overspreading Southcentral, will help shower activity increase in
coverage. Showers will first affect the Copper River Basin
through tonight, then spread into the Susitna Valley through the
morning hours tomorrow. Temperatures this afternoon range from the
50s to low 60s, the warmer spots having seen more breaks in cloud
cover. Despite the clouds, the combination of daytime heating,
along with the current passage of the shortwave trough and
building coastal ridge, should result in renewed gap winds
developing through the remainder of the evening hours. Favorable
areas for the strongest winds will be through the Turnagain Arm,
out of the Knik River Valley, and up through much of the Copper
River Basin. As the trough departs the region on Thursday, shower
activity will gradually taper off from east to west.

A low threat for an isolated wet thunderstorm or two is again
possible this evening, especially near the Tok Cutoff, with a
lesser chance further west from the Talkeetnas into the northern
Susitna Valley. Thunderstorm chances go down even further on
Thursday with continued cloud cover to limit instability.
Subsidence on the backside of the departing trough will also help
to keep a lid on any storm development. Gap winds return Thursday
afternoon and evening, though to a lesser extent.

Further south, an upper low will lift over Kodiak Island and
become mostly stationary tomorrow morning. Its front will make
very slow northward movement, not reaching the Gulf coast until
late Friday or early Saturday. Showery conditions and small craft
conditions are forecast from the Shelikof Strait into much of the
Gulf on Thursday, with winds diminishing late Friday as the front
dissipates along the Gulf coast. Friday will thus see improved
conditions across the Gulf as well as improved conditions further
inland of Southcentral.

BL


&&


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

An area of low pressure in the Bering Sea allows for waves of
moisture to push through the Alaska Peninsula and Southwest Alaska
through tomorrow morning. Simultaneously, weak ridging over
interior portions of the Southwest bring the chance of isolated
thunderstorms to the Kuskokwim Valley and Delta. High pressure
builds into the Aleutians Friday.

An area of low pressure in the Bering Sea migrates slowly
southeastward through the overnight hours. This will bring waves
of moisture to the Alaska Peninsula and the Eastern Aleutians
resulting in rain showers overnight into early tomorrow morning
with rainfall amounts of a few hundredths expected. Heavier
rain showers and areas of isolated thunderstorms from a westward
moving trough this evening and overnight are expected. This will
result in pockets of heavy rainfall from Aniak to Sleetmute
northward.

As the Bering low moves into the North Pacific, a separate low
moves through the northern part of the Kuskokwim Delta. This
brings widespread rain showers to the area late tomorrow morning
and into Friday morning. Rainfall amounts ranging from 0.25" to
0.50" from Sleetmute to Aniak southwestward to Bethel and into the
rest of the Kuskokwim Delta.

High pressure builds in the Aleutians Friday causing
northerly flow and fog for the Western and Central Aleutians.

&&


.LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)...

On the Alaska Weather map, little overall changes on the previous
forecasts. A closed upper level low continues to meander around
the Central Gulf of Alaska through the forecast period. Over the
Bering, an upper ridge pushes into the Western Mainland to link up
with a ridge over the Northern parts of the state. Tuesday sees a
new upper level trough from the North Pacific slipping into the
Western Aleutians and Bering through midweek. The GFS and means
covers the entire region throughout the forecast, with the other
models diverging in the development over the Aleutians and Bering
from Monday on.

Locally moderate showers and scattered thunderstorm activity is
expected from the middle Alaska Range to the Eastern Interior
through Monday. Scattered showers continue over the Southern
Mainland through midweek. Coastal zones from the Alaska Peninsula
and Kodiak Island to the Canadian border are expected to see
locally moderate rain driven onshore by the offshore surface low,
fronts and troughs wheeling East to West. With the approaching
North Pacific upper trough, a surface low and front spreads
locally moderate rain and breezy conditions across the Western and
Central Aleutians and Bering Monday through Wednesday.

- Kutz

&&


.AVIATION...

PANC...VFR conditions prevail through the TAF period. Turnagain
Arm winds increase this afternoon as a front moves across the
southwest Gulf with gusts up to 30 kt expected. Gusts up to 35 kt
are possible between 2Z and 6Z as an upper level shortwave moves
through the area.

&&


$$