Kenai, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

302
FXAK68 PAFC 170119
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
519 PM AKDT Wed Apr 16 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Wednesday afternoon through Saturday afternoon)...

Stormy weather continues as a Bristol Bay low pushes its front
across Southcentral Alaska. High Wind Warnings remain in effect
for Anchorage Hillside / Upper Eagle River and Portage Valley
through late tonight. Conditions slowly begin to improve this
evening as the warm front slides eastward. However, moderate to
heavy precipitation will linger along Eastern Kenai Peninsula and
Prince William Sound through Friday morning as onshore flow
persists. From about Friday afternoon through Saturday, much more
benign conditions and rain/snow showers as the low currently near
Bristol Bay finally exits towards Southeast Alaska.

Diving into the details... as was hinted in model trends
yesterday, today`s high wind event is looking more subdued than
initially forecast 2 days ago. As of 4 PM, the highest observed
gust in Portage has been 73 mph, just shy of the 75 mph needed for
high wind criteria. For the Anchorage Hillside and Upper Eagle
River, a strong north-south pressure gradient (7-8 mb between
Anchorage and Homer) delayed the onset of the strongest winds
until after 9 AM. Still, there was an observation of a 91 mph
gust in Bear Valley, and a 71 mph gust in Glen Alps. Winds have
diminished this afternoon as the light rain that moved in earlier
today may have stabilized the lower atmosphere, keeping the
stronger winds aloft from mixing down. Confidence is high that the
winds will diminish around 10 PM; if observations show winds
trending downwards and remaining safely below high wind thresholds,
the upper elevation Anchorage/Eagle River High Wind Warning may be
canceled before the scheduled 1 AM expiration time.

Outside of the areas under a High Wind Warning, winds have also
been quite impressive. The hefty east- west pressure gradient has
produced gusts of 50-55 mph in Mat Valley and Copper River
Valley, as well as 35-45 mph through Kenai. 24-hour precipitation
totals have ranged from a quarter to half inch in Valdez and
Cordova, a half inch to 1 inch for Whittier and parts of Prince
William Sound, and an inch or greater in Seward, Chenega, and
Kodiak.

Weather conditions improve through Thursday morning, though the
weather will remain unsettled until Saturday. A robust shortwave
moving northwards into the Mainland will bring a quick round of
light precipitation to Western Kenai Peninsula, Anchorage, and/or
Mat Valley sometime late tonight through Thursday morning, with
considerable uncertainty in timing. Regardless, precipitation
amounts will be fairly low. Precipitation will gradually become
more showery through Thursday as the occluded low moves through,
with highest precipitation amounts expected along Eastern Kenai
Peninsula and especially Prince William Sound. By Saturday, much
drier conditions are forecast as the low exits towards Southeast
Alaska, with showers lingering along west- and south-facing slopes
of the Talkeetna, Kenai, and Chugach Ranges.

-Chen

&&


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


The forecast continues to remain on track this afternoon as the
eastern Bering low has pushed its front across mainland Southwest
Alaska today. Southeasterly winds along the northern Alaska
Peninsula and Bristol Bay remain gusty this afternoon with
Koliganek still seeing gusts of 40-50 mph. These winds are
expected to continue to diminish throughout this evening as the
low begins to weaken and push inland. Elsewhere across Southwest
Alaska, temperatures have warmed enough for showers to change over
to rain for the Interior Kuskokwim Delta and Kuskokwim Delta
Coast. Snow and reduced visibilities have persisted across Nunivak
Island throughout the day today, but conditions should begin to
improve throughout the rest of this afternoon and evening as
warmer temperatures moving in have allowed for rain to begin to
mix in.

The impactful winter storm across the Eastern Aleutians is
beginning to wrap up as precipitation tapers off and the strongest
winds shift to the east through this evening. The worst of the
conditions have shifted to the east towards the Southern AKPen
today with gusts up to 40-50 mph and snow leading to reduced
visibilities. Temperatures hovering just above freezing have
allowed for brief periods of mixed precipitation, but visibilities
reduced to one mile with instances of a half-mile remain possible
throughout tonight. Conditions will improve throughout the
morning on Thursday as the low weakens and moves inland.

Showery conditions continue across mainland Southwest Alaska into
Friday as the eastern Bering low opens into a surface trough and
lifts into Interior Alaska. Quiet conditions are expected for
Saturday as a ridge builds in overhead. Meanwhile, the Bering and
Aleutian Chain will remain unsettled Thursday through Saturday. A
Kamchatka front moves across the Western Aleutians to the Eastern
Aleutians Thursday through Friday, bringing rain and southeast
winds with it. This system is not all that impressive as it will
weaken on it trek eastward. Another North Pacific low lifts to the
Western Central Aleutians by Saturday bringing another round of
rain and southeast winds.

&&

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

The majority of active weather will be working its way across the
Aleutians and Bering through Tuesday before crossing over into
the Gulf of Alaska for Wednesday. A broad surface ridge slides
across the Interior into Canada by Monday, leaving an extended
area of low pressure from the Russian Far East to the Canadian
Border by Wednesday. Uncertainty with the weather features
increases through the period, especially considering an energetic
GFS accelerating ahead if the other models through midweek. A well
developed surface low in the Western Bering on Sunday extends a
front across the Central Alaska Peninsula and Eastern Aleutians
Sunday. Ahead of the front snow changes to rain across the
Northern Bering through St Matthew and Nunivak Islands. All rain
is expected over Bristol Bay and areas South for Sunday. Rain
pushes over Kodiak Island and Southwest Alaska with areas of
possible freezing rain over the Northern Bering for Monday. The
Western Bering low progresses into the Eastern Bering by Tuesday,
before crossing the AKPEN for Wednesday. Areas of moderate rain
continue across Southcentral Alaska through late Tuesday before
diminishing. A strong North Pacific low and front spreads locally
heavy rain across the Western Aleutians and Bering late Monday,
and continues into the Central Aleutians and Bering for late
Tuesday into Wednesday.

- Kutz

&&

.AVIATION...

PANC...The main aviation concern into this evening will be the
low-level wind shear with northwesterly winds at the surface and
strong Southeast winds at and above 1000 ft this afternoon. This
is one of those particularly bad wind shear scenarios as the winds
between the surface and 1000 ft could be 180 degrees opposed. As
the winds aloft descend through the evening, the wind shear will
end as the surface winds become strong and gusty from the
southeast. Timing this is a little bit of a challenge as the winds
through Turnagain Arm and aloft will be strong the whole time, but
when they are able to make in into the terminal, and if they come
through in full force are still question marks.

Thursday is expected to see southeast winds at all levels over
the terminal, but they will not be as strong as today through
tonight. Periods of rain are expected through Thursday, but the
most likely time for MVFR ceilings will be tomorrow as the lower
winds and more saturated atmosphere should lead to lower ceiling
heights.

&&


$$