Small Craft Advisory 239, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
446 AM AKDT Thu Mar 12 2026

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

Discussion:

Clear skies and cold temperatures again this morning across
Southcentral as cold and dry northerly flow persist; however,
temperatures will warm slightly over the next few days as cloud
cover begins to increase ahead of an approaching disturbance.
While gusty gap flow winds are still ongoing this morning, winds
will be on the decrease by this afternoon as the gradient relaxes
over the coastal mountains.

The complex low over the Gulf will continue to move east and
weaken today with ridging over the Interior. Models are in good
agreement with a trough dropping southwards across Southwest
Alaska tonight and fairly good agreement with another trough
dropping south across the Interior. This second low Saturday into
Sunday will be the next chance for precipitation for parts of
Southcentral. The surface low from the first trough will slowly
drift north across the Gulf to merge with the another weak low.
The low will further deepen as the second trough digs towards the
Gulf. Moisture will start to advect north along the coast and
eventually into the Copper Basin where light snow chances will
increase through Saturday night and into Sunday morning. Models
are still trying to figure out how widespread light snow will
develop, but it does look like best chances will mainly along and
east of the Kenai and Chugach Mountains.

- PP

&&

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

The persistent cold northerly flow continues over Southwest
Alaska and the Bering Sea. Generally, much of interior Southwest
Alaska and the western Bering Sea will continue to stay dry, while
the Kuskokwim Delta, Alaska Peninsula, and eastern Aleutians will
contend with snow showers and blowing snow as shortwaves track
southwards around the ridge and across western AK and the eastern
Bering Sea.

A shortwave dropping south across the eastern Bering Sea will
allow for snow showers to continue across the Kuskokwim Delta,
Nunivak Island, and the Alaska Peninsula today. Winds along the
Alaska Peninsula and the Kuskokwim Delta coastline remain breezy,
allowing for the continued possibility for mild blowing snow and
reduced visibilities. As this current system tracks south into the
northern Pacific by this afternoon, a deeper and more defined
upper level wave will take a similar track southward across the
eastern Bering Sea through Friday morning. Snow shower coverage
along the Kuskokwim Delta coast will increase this afternoon into
tonight as a result, while frequent snow showers along the AKPen
likely persist from this morning through Friday. The eastern
Aleutians from Nikolski to Akutan likely become the focus of the
strongest winds and heaviest snowfall late tonight into early
Friday morning with this system. Beyond Friday, conditions dry out
while the same pattern of ridging across the western Bering and
northerly flow across the eastern Bering and Southwest Alaska
continues.

-JH

&&

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

The long-term forecast begins late Saturday with the persistent
upper-level ridge over the western Bering and Aleutians remaining
firmly entrenched over the region. Downstream, a positively tilted
upper-level trough digs southeast, with an embedded shortwave
over the Interior elongating as it reaches the Southern Mainland.
With the upper-level trough axis draped over the Alaska Range and
Alaska Peninsula, diffluence and a strengthening southerly flow
ahead of the trough axis will likely allow for both a surface
trough/low and moisture from the Gulf to be lifted northward
across coastal Southcentral late Saturday night into Sunday. How
these features interact, the amount of moisture, and timing of any
precipitation is still fairly uncertain; however, there is the
potential for light snow across portions of interior Southcentral
with steadier snow and wind for coastal locations.

Another complicating factor will be a secondary upper-level
trough digging south on the heels of the first for Sunday. This
feature looks more potent in recent model runs, digging south a
bit farther west than the first trough. If this solution holds,
this second trough would likely help further enhance the surface
trough/low over the northwestern Gulf and draw up more moisture in
the form of snow for Southcentral and Kodiak Island through
Monday. Moreover, this trough will usher in yet another round of
arctic air and gusty northerly winds into Southwest Alaska.

Uncertainty grows by the start of next week as to how quickly
this trough closes off into an upper-level low as it moves south
over the Gulf. If this feature does move quickly into the Gulf,
any snow will likely follow suit and taper off across the
Southcentral coast as the arctic airmass moves in. If the trough
lingers, expect snow to linger with a slight delay in arrival of
arctic air and strongest of gap winds.

&&

.AVIATION...

PANC...VFR conditions and winds under 10 kts will persist through
the TAF period.

&&