Kenai, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

398
FXAK68 PAFC 201246
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
446 AM AKDT Tue Oct 20 2026

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

Key Messages:

- A strong storm system moving into Prince William Sound this
  morning will continue to bring widespread rain and snow from
  the Western Chugach and Talkeetna Mountains east across the
  Copper River Basin through Tuesday night.

- Multiple Winter Weather Advisories remain in effect for snow
  from Hatcher Pass, Matanuska Valley, and Anchorage Bowl east
  across the Northern and Western Copper River Basin and Thompson
  Pass.

- Temperatures trend colder for the latter half of the week in the
  wake of this storm system.

Discussion:

A potent upper-level wave is driving east from Southwest Alaska
into the northwestern Gulf of Alaska this morning along with a
strong surface low entering western Prince William Sound. Location
of the low is easily noted with surface observations showing gusty
ESE winds from Cordova to Bligh Reef and a strengthening westerly
wind from Whittier through Passage Canal. Given the faster and
more easterly track of the low and upper-level wave first noted
yesterday, there is already a clear cutoff in the precipitation
from the far western Susitna Valley south across Cook Inlet as of
4 AM this morning.

Overall, impacts from this system look on track, with widespread
precipitation, mainly in the form of snow, or a rain/snow mix at
the lowest of elevations, from Anchorage and Talkeetna east
across the Copper River Basin. The heaviest of the precipitation
still looks to be from Prince William Sound into the Copper River
Basin through late this evening before slowly tapering off through
Wednesday morning. Farther west, the precipitation will continue
until later this afternoon across the Anchorage Bowl, Hillside,
and Mat Valley. The northwesterly flow aloft and weak cold air
advection will favor higher snow amounts along the western
foothills of the Chugach from Sutton south to Eagle River and the
Anchorage Hillside. A light southwesterly wind at the surface
later this morning across Cook Inlet will likely keep West
Anchorage warm enough to allow for any snow early this morning to
change back to rain before ending. Nonetheless, parts of the
Anchorage Bowl and Mat Valley could see several inches of slushy
accumulation, mainly on elevated and grassy surfaces. Snow will
probably struggle to consistently stick on roadways close to sea
level, especially after sunrise, mainly due to the still
seasonably warm ground temperatures. At higher elevations and
where temperatures will remain colder, much higher storm total
snowfall amounts remain on track. An additional 6-12" is expected
across much of the Anchorage Hillside and along the Glenn Highway
from Sutton east to Tolsona. Even higher additional amounts on the
order of 12" or more are expected near the top of Thompson Pass
and along northern parts of the Richardson Highway near Paxson.

By late Tuesday into Wednesday, snow will let up as a lingering
upper level trough drifts slowly southeast towards the Copper
Basin and northern Gulf and as a cooler air mass filters in from
the northwest. Gusty northwest gap winds will linger across the
western Gulf through Wednesday as the then weakening low drifts
east across the Gulf while northwest flow continues to pull cool
air across the AKPen. Meanwhile, overnight lows across the bulk of
Southcentral will be much colder, dipping into the teens and 20s
in most spots for early Wednesday and Thursday morning, and perhaps
even into the single digits for portions of the Copper River
Valley if skies remain clear. Cool and dry conditions will persist
into Thursday as a developing upper ridge begins to encroach onto
Southcentral from the west.

-AS/TM

&&


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

The overall weather patter for the next couple of days will be
fairly low-impact. Light snow may linger across portions of
Southwest Alaska, however, additional accumulations are not
expected. The next front extends off a strengthening low
developing over the Kamchatka Peninsula mid week. The front will
move into the western Bering Sea Wednesday afternoon and traverse
across the Bering Sea towards the Southwest coast through Thursday
night. Widespread gale force and small craft winds will encompass
the Bering Sea with a core of storm force winds along the front.
Additionally, expect a swath of warmer air and moderate to heavy
rain along the Aleutian Chain. As the front approaches the
Southwest coast Friday, precipitation and gusty southwesterly
small craft to gale force winds will start to push inland.

KM

&&


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

Key Messages:

* A series of strong storms move across the Bering Sea and into
  Alaska from Friday through the weekend, bringing strong winds
  and heavy precipitation.

* Though confidence is low in exact impacts at this time, strong
  onshore winds and elevated coastal water levels are a concern
  for Southwest Alaska, mainly Friday and Saturday and again on
  Monday.

Discussion:

The biggest story in the long-term forecast will be a strong low
transiting from the Kamchatka Peninsula to Alaska. Ensembles are
in relatively good agreement with this storm, with seemingly
higher-than-average forecast confidence given that this feature is
4 to 7 days out. Good run-to-run consistency among deterministic
global models is also contributing to higher-than-average forecast
confidence. The areas of highest agreement with this feature are
for gale to storm force sustained winds along the front as it
moves across the Aleutian Chain, the Southwest Alaska coastline,
and the Alaska Peninsula. These onshore winds are raising
concerns for coastal impacts (including high surf and perhaps even
coastal flooding) for south-facing portions of the Western coast.
It`s still too early to say for now what projected water levels
will be, but we will be closely monitoring this storm.
Southcentral should be spared the worst of the winds with this
storm, as the front will very likely be weakening by the time it
exits Southwest Alaska.

In addition to winds, there will also be plenty of moisture along
the front, which will bring periods of moderate to heavy
precipitation to the Aleutians, Alaska Peninsula, and Southwest
Alaska. Precipitation amounts are uncertain at this time, as
overall amounts will be dependent on where the front may slow down
and linger as upper waves move through. Given the strong winds
associated with the front, there will likely also be areas of
downsloping that will reduce precipitation totals. While warm air
advection will likely keep precipitation mostly rain for the
majority of Southwest Alaska, colder air lingering in Southcentral
could mean that lower elevation areas may see snow.


&&

.AVIATION...

PANC...A low moving through the Gulf today will bring a mix of
rain/snow showers through 18Z before changing back to all rain
before ending this evening. Snowfall accumulation is not expected.
MVFR conditions will continue through 23Z today. Gusts to 15
knots from 16Z to 20Z with diminishing winds afterward. IFR
conditions return this evening.





$$