Gale Warning 319, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
411 PM AKDT Tue Apr 21 2026

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

Key Points:

* Unseasonably wet and windy weather is on the way for Wednesday
  through Friday.

* The wettest weather will be the eastern Kenai Peninsula, Prince
  William Sound, and the Susitna Valley with rainfall totals of 1
  to 3 inches expected for most communities.

* Strong and gusty southeasterly gap winds will develop Wednesday
  and persist through at least Thursday. Locations that will see
  some of the strongest winds include Turnagain Arm, Anchorage
  Hillside, south to west Anchorage, Palmer and the Knik River
  Valley, and Glennallen and the Copper River.

A large and deep vertically stacked low is nearly stationary over
the southern Bering Sea. A strong short-wave lifting northward
along the eastern side of the trough is leading to amplification
of a downstream ridge, which is building from Southwest Alaska
north and east across the mainland. An atmospheric river extends
from the tropical Pacific northward to the Bering Sea low. While
total precipitation values are not all that impressive at less
than 1 inch, this is the driest time of year for Alaska and these
values are 200% to 285% of normal for the time of year. A frontal
system is spreading out from the low center across the northern
and eastern Bering Sea. A weak warm front is lifting northward
across Bristol Bay and the western Gulf, with a band of light
precipitation noted in radar imagery. For the moment, much of
Southcentral is quiet, under mostly sunny skies - but a change
back to cloudy, windy, and rainy is on the way.

On Wednesday, we will establish the large scale pattern that will
hold through the remainder of the week. The upper level flow will
continue to amplify and shift eastward, with the ridge ultimately
setting up shop over the eastern Gulf northward to the Yukon. This
will establish deep southerly flow and moisture transport from the
north-central Pacific to Southcentral. Multiple short-waves will
track from south to north through the week and combine with strong
low level southerly upslope flow to produce widespread significant
rainfall for coastal areas as well as the Susitna Valley. There is
some model spread in the track and amplitude of individual short-
waves which could shift the area of heaviest precipitation.
However, no matter the track of individual short-waves, the
eastern Kenai Peninsula and Prince William Sound regions will see
the brunt of precipitation and winds. Precipitation will fall as
all rain at sea level, with snow levels ranging from roughly 1500
to 3000 feet above sea level Wednesday through Friday. There seems
to be enough shifting of the location of heaviest rain as short-
waves and surface fronts move through, so no one location sits in
the heavy rain for too long. Based on this, do not expect
any flooding. However, will continue to monitor changes in model
guidance to ensure this doesn't change. Inland areas from the
western kenai to Anchorage, the Matanuska Valley, and the Copper
River Valley will see some downslope flow, which will limit
rainfall duration and amounts.

-SEB

&&

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

A strong front associated with a strong Bering low is pushing
north and eastward, bringing mixed precipitation and gusty winds
to the Alaska Peninsula, Southwest Alaska mainland, and Nunivak
Island. By late this afternoon, the storm in the Bering will
strengthen to storm-force on the northern periphery of the system
west of the Pribilofs. Heavy rain will move over False Pass, King
Cove, Cold Bay, and Sand Point by this evening. Gap areas in the
Fox Islands and the Alaska Peninsula will see stronger gusts as
the front passes.

The front pushing along the Southwest coastline late tonight will
initially bring light to moderate snowfall and gusty winds to
Nunivak Island and the Kuskokwim Delta. These gusty winds and
snowfall will combine to promote localized blowing snow
conditions, reducing visibility to 1/2 mile or less at times into
Wednesday morning. Inland areas north and west of Bethel will see
blowing snow as well. Also, a period of freezing rain mixed with
snow is expected over the Kuskokwim Delta early Wednesday morning.
Due to this threat, the Winter Weather Advisory now includes the
inland Kuskokwim Delta. By Wednesday afternoon, temperatures will
warm above freezing and precipitation will reduce in intensity
over the Southwest Mainland as the front pushes eastward. The low
itself will be positioned west of the Pribilof Islands by this
time, bringing more gusty winds and precipitation over the
Aleutians and Pribilof Islands. Gap areas over the Fox Islands and
Alaska Peninsula will once again see stronger gusts during this
period.

The low will weaken as it moves northeastward. By Friday, winds
and chances for precipitation will have diminished over the Bering
and the Southwest Mainland. However, lingering showers will
prevail across Southwest Alaska. These will likely be rain during
the day and a mix of rain and snow at night.

-CL

&&

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

Unsettled weather continues across much of Alaska through the
weekend as a North Pacific low moves into the southern Bering near
Adak Sunday morning. The system tracks northeast past the Pribilof
Islands Sunday night and then slows west of Nunivak Island into
Monday. This will bring widespread gale-force winds across the
southern and eastern Bering and Bristol Bay, though the strongest
winds are expected to stay offshore. Coastal impacts look minimal
for now, thanks to shorefast ice and additional protection from
the extensive ice pack over the eastern Bering.

The front tied to this system will push into the western Gulf,
tapping into a steady stream of moisture. Coastal areas along the
northern Gulf, Kodiak Island, and higher terrain of the Alaska
Range will see the heaviest precipitation. Inland locations will
experience several days of lighter precipitation, with rain at
lower elevations and snow at higher elevations. A southeasterly
flow will also promote some downsloping, especially west of the
Chugach and Kenai Mountains, which could limit precipitation in
those areas.

Confidence in track has improved, with most guidance keeping the
low west to just northwest of Nunivak Island. This setup favors a
steady feed of moisture into Southcentral and Southeast Alaska.
One outlier (ECMWF) shifts the low farther west toward the
Pribilofs, which would increase winds and precipitation there,
but overall impacts elsewhere remain similar. As the system
weakens and shortwaves rotate around it, precipitation over
Southwest Alaska should gradually become less intense through the
first half of the week.

LM

&&

.AVIATION...

PANC...Gusty winds are expected to become light from the south to
southeasterly by this evening. VFR is expected through the rest
of the day today. There is a small chance for ceilings to dip into
MVFR with a brief shower ahead of the approaching front after
midnight tonight. Chances for rain and MVFR ceilings become more
likely by 12Z. Southeast winds will increase later Wednesday
morning and any potential for downslope drying could help to
lighten precipitation and lift those ceilings into VFR Wednesday
afternoon. Turnagain Arm winds will increase Tuesday afternoon,
initially turning more down inlet then out towards Fire Islands
and beginning to bend towards the terminal by Wednesday evening.

&&