Nikiski, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

199
FXAK68 PAFC 041302
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
502 AM AKDT Sat Jul 4 2026

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

The 4th of July is starting out about as soggy as anticipated
across Anchorage and much of the Mat-Su Valleys this morning. A
shortwave trough extending out ahead of a deep upper-level to our
west is making steady progress north this morning, now moving up
the Cook Inlet and along the Kenai Peninsula. Scattered showers
have transitioned to a band of steady rainfall along this trough
axis overnight. This band of light to moderate rainfall is
currently moving across Anchorage and much of the southern Susitna
Valley, and is beginning spread into much of the remainder of the
Mat-Su.

Farther south, a secondary shortwave embedded within the southern
side of the large upper low over Southwest is moving northeast
along the Alaska Peninsula, helping to spin up a new surface low
just off to the west of Kodiak Island. This low will continue to
deepen as it pivots northeast towards the north end of Kodiak
Island today, sending another batch of steady rain north from
Kodiak Island into the southern Kenai Peninsula as it does so.
Spots along the coast from Whittier south will see steady rain
pick up through the afternoon and evening as increasing
southeasterly winds upslope into the coastal mountains and wring
out increasing moisture ahead of the low to the west. In contrast,
inland areas should see steady rain taper off to scattered
showers by this afternoon. Potential for thunderstorms will also
be substantially more limited today thanks to cooler temperatures
and much higher cloud cover. The best chance (around 30%) to see a
few lightning strikes will be focused over the Copper Basin near
the Alaska Range.

From tonight into Sunday, the main low will shift east out into
the central Gulf. This will mark the start of a warming/drying
trend as northeasterly flow between the departing low and a
building ridge over the Interior begins to pick up and drag a
warmer air mass southwards into the region. Most valley areas
should see highs jump back up into the mid to upper 60s, with
cooler temperatures in the mid to upper 50s lingering along the
Gulf Coast. Rain will also be slower to clear out near Whittier,
Seward and Kodiak, and might not fully taper off until Sunday
night. Any isolated thunderstorms will again be most likely near
the Alaska Range and parts of the Talkeetna Mountains for Sunday
afternoon.

The warming trend will continue into Monday as the low drifts into
the eastern Gulf and as the ridge over the central and northern
Mainland continues to build. Afternoon highs could breach 70 over
interior valleys, and perhaps even 75 in a few spots. Potential
for thunderstorms will also increase markedly once again as
instability increases with the warming temperatures. The highest
chance (around 70%) for isolated to widely scattered storms will
be focused over the Talkeetnas and Susitna Valley.

-AS

&&


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

The dominant weather feature continues to be an upper low
currently approaching Bristol Bay. A robust shortwave coming
around the backside of the low is bringing steady rain along the
Alaska Peninsula early this morning, with rain set to spread north
up the Alaska Peninsula to Naknek, Iliamna and interior Bristol
Bay later today. The entire storm system will exit eastward to the
Gulf through Sunday. One change since the previous forecast has
been a slowing of the system`s exit, and the spread of rain
further west into Bristol Bay. As such, rain is now forecast to
linger over Bristol Bay through much of today.

With the storm system exiting Sunday, building high pressure and
northerly low level flow will lead to warming and drying
conditions under partly to mostly sunny skies. This will establish
a thermal trough inland which will serve as the focus for
isolated to scattered afternoon and evening showers and
thunderstorms both Sunday and Monday. With daytime highs warming
into the high 60s to low 70s through much of Southwest Alaska for
Monday, thunderstorm potential could extend over much of Southwest
Alaska Monday afternoon and evening, from Kuskokwim Valley down
to interior Bristol Bay.

Out west, a front will bring rain and elevated winds for the
Aleutians (from the Rat Islands eastward to Atka) through tonight.
An upper level low over the northwest Pacific, combined with
short-waves riding the subtropical jet from the Pacific up to the
Aleutians, will reinvigorate the leading front and help bring
additional rainfall through Monday. However, the latest guidance
is now suggesting that the heaviest stream of moisture will dip
south before reaching Unalaska, resulting in a reduction in
forecast rain amounts. Regardless, the aforementioned "tropical
airmass" will lead to an increase in low clouds and fog along the
Aleutians and into the southern Bering Sea.

-SEB/KC

&&


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

Sunnier and warmer weather on Tuesday for southcentral Alaska.
Tuesday evening will begin to see mostly cloudy with chances of
showers from an upper level low entering the Gulf, then exiting by
Wednesday. A second upper level low shortly follows continuing
the conditions, which is mentioned later.

A Bering low north of the Aleutians and Saint Paul Island will
progress toward the Bering Strait. The low reaches the eastern
Bering by Wednesday and weakens over the Bering Strait before
Thursday, bringing showers and wind to the Aleutian chain and
Southwest Alaska.

An upper level low develops from the weakened Bering low near
Kodiak Island Wednesday afternoon. This progresses eastward and
brings mostly cloudy skies with showers for the rest of the week
for southcentral.

-SS

&&
.AVIATION...

PANC...A trough works its way up the Cook Inlet this morning,
bringing rain showers and MVFR vis/cigs. VFR conditions will
return by around 20Z as steadier rain showers taper off, with
ceilings remaining below 5,000 ft. As southeasterly flow
increases, a Turnagain Arm wind is expected to develop by around
0Z this afternoon, bringing gusts up to 25 kts and ceilings above
5,000 ft. This downslope flow should keep most rain showers out of
the Anchorage Bowl, though a passing shower or two can not be
ruled out. Turnagain Arm winds will diminish by around 9Z tonight,
with light northerly surface winds prevailing through tomorrow
morning.

-CW

&&


$$