Small Craft Advisory 55, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
503 PM AKST Sun Jan 18 2026

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

A weak upper level wave, lifting north of Kodiak, will continue
to interact with a trough dropping in from Western Alaska. As the
trough approaches, it will stall out as it interacts with a slowly
expanding region of high pressure that spans southeast Alaska.
Light snow that stretches from Tyonek northeast to Trapper Creek,
will slowly diminish as the trough slows down and moisture gets
pinched off.

The biggest forecast challenge tonight will be on whether or not
low lying areas see any fog or not. Moisture across the region
remains high, but mid and high level cloudcover is widespread.
Some of the thickest clouds are associated with the trough
approaching from the west this afternoon. There may be a window on
Monday morning that if the trough pushes east of Anchorage and
over Prince William Sound, that we may clear out some, as weak
high pressure from the Kusko tries to build in. Then it is a
question of much low level winds slow and if fog, vs a low stratus
deck develop. The going forecast hints at patchy fog development,
but confidence is not strong with that spreading out over the
area. Model guidance is all over the board, with the NAM being the
most pessimistic. High resolution guidance (RRFS, REFS, HRRR,
HREF, etc) are all highlighting a bit more wind from the surface
to 1000 ft, promoting better mixing and signaling more of a
stratus deck than fog solution.

Building into mid week, the bulk of the south central mainland will
see conditions remaining dry and cooling day by day. Meanwhile, A
fresh north Pacific shortwave will ride the high pressure ridge,
impacting Kodiak Monday with rain showers persisting on and off
through Wednesday.

&&

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

KEY MESSAGES:

 1) Southerly flow continues through Tuesday across most of
mainland Southwest Alaska and he Aleutians with light
precipitation likely along the southwest coast Monday night into
Tuesday.

 2) Two fast-moving North Pacific lows the next 48 hours bring
snow, rain and gale-force winds to the Western / Central
Aleutians.

Discussion:

Dry conditions continue into tomorrow evening across the Mainland,
AK Pen and Eastern Aleutians with period of rain and snow in the
Western and Central Aleutians. Southerly air will continue to push
highs in the Mainland in the lower 30s and into the Aleutians,
the lower 40s, today and tomorrow.

Two areas of concern are being watched from tomorrow evening into
Tuesday afternoon. The first is the Eastern Aleutians, AK Pen and
coastal Mainland area where a weak low moves through tomorrow
evening through Tuesday morning. This low will cause surface
rain/snow showers and isolated pockets of freezing drizzle and
snow in higher elevated areas during this time. The greatest
chance for precipitation will be from along the coast Dillingham
northward to Nunivak Island. Temperatures will be hovering around
freezing at the surface though continued southerly flow brings
warm air at higher levels. Temperatures will remain in the 30s/40s
Tuesday. The location of freezing drizzle tomorrow evening into
Tuesday will be similar to this morning. Upper- level ridging
builds in across Southwest Alaska Tuesday afternoon keeping most
of the area dry into mid- week.

Across the marine zones of the Aleutian Chain, expect gale-force
winds with persistent southeasterlies stretching from Adak to
Akutan are expected the rest of today as the first of two lows
move through the area. A second North Pacific low lifts to Adak
and Atka Monday evening with more gusty easterly to southeasterly
winds and rain. This system looks to be solidly rain at the onset.
As it moves north into the Bering through Tuesday, expect cold
air to wrap around it and work into the Central and Western
Aleutians through Tuesday evening and Wednesday morning resulting
in snow showers. Another front approaches the Western Aleutians by
Wednesday morning with more gale-force southeasterlies across the
Western Aleutian marine zones.

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

Confidence is higher than usual for high pressure to build across
the state for the majority of the long range. The resulting omega
block pattern is expected to bring seasonable and quiet weather
to much of the Mainland. There continues to be a strong signal for
persistent upper level troughing over Kamchatka and the far
Western Bering Sea through the period. Several shortwaves and
accompanying surface lows will lift from the North Pacific and
into the western Bering through mid to late this week, keeping
unsettled and active weather mainly confined to the Western and
Central Aleutians. Each wave will move in succession through the
Aleutians and Bering Sea, bringing multiple rounds of potentially
gale to storm force winds and precipitation through this week.
However, the main foreseeable challenge would be with the timing
of each low that lifts north across the area.

The upper level ridge looks to retreat to the northwest towards
eastern Siberia and the northern Bering by the end of the weekend,
allowing for an Arctic trough to dig south across the interior
while North Pacific disturbances lift into the Gulf. Models remain
in fairly good agreement on the shift to a more active pattern
for the weekend into early next week, bringing increased
precipitation chances along the Alaska Peninsula and Southcentral
and cooler temperatures across the southern Mainland.

JH

&&

.AVIATION...

PANC...Light northerly winds around 10 kts or less will persist.
Conditions will be favorable for low stratus or fog development
beginning this evening as high pressure builds over the region.

&&