Winter Weather Advisory 21, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
549 AM AKST Mon Feb 9 2026

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

A vigorous upper-level shortwave over the Susitna Valley this
morning will continue to slide east over the Copper River Basin
today before exiting the region tonight. Low-level southwesterly
flow and weak isentropic lift ahead of this wave is resulting in
widespread light snow from northern Cook Inlet into the Mat-Su
Valleys. The snow is not expected to amount to much, on the order
of up to an inch over most locations and up to two inches toward
Sutton and Hatcher Pass, before tapering off by around noon.

An area of low pressure at the surface positioned over the eastern
Kenai Peninsula this morning will move northeast into the Copper
River Basin, embedded in the southwesterly flow out ahead of the
eastward moving shortwave. This surface low is tapping into
a deep moisture feed over the Gulf and advecting it through Prince
William Sound into the coastal mountains and the Copper River
Basin. Light snow over the basin this morning will be enhanced by
this additional moisture, resulting in more widespread moderate to
heavy snow mid-morning through mid-afternoon before slowly
tapering off from west to east. Upslope area in the eastern half
of the Copper River Basin will likely still see several more
inches of snow before the event winds down. Gusty winds in
Mentasta Pass and along portions of the Tok Cutoff may result in
some localized blowing snow at times.

The focus then turns back to the west for Tuesday as this first
system departs the region. A transient ridge moving over
Southcentral Tuesday quickly exits as a strong front moves from
the western Gulf to the northern Gulf with gales across western
half of the Gulf and snow changing to rain for Kodiak Island. Snow
will overspread the Kenai Peninsula, Cook Inlet, Anchorage Bowl,
and parts of the Mat-Su Valleys by late Tuesday morning as the
front moves to the northern Gulf. Strong southeasterly winds aloft
out ahead of the front will likely allow any snow over the lee of
the coastal mountains to diminish in intensity by Tuesday
afternoon due to downsloping, but not before around an inch of
snow or snow for places like Anchorage. Moreover, strengthening
southeasterly surface winds will also allow for some warmer air
near the surface to work into the eastern Kenai, likely resulting
in any snow at the onset to change to a rain/snow mix, especially
for Whittier and Portage. Seward may see all snow due to a lack of
wind on Tuesday.

Forecast uncertainty builds by late Tuesday as a surface low
develops along the triple point of the occluded front. The big
question is where does this low spin up and track. Recent hi-res
and NAM runs have shifted the low track to the west, with some
guidance bringing the low up Cook Inlet. The GFS/EC/GEM all keep
the low east of the Kenai Peninsula, albeit at different
locations. The forecast favors the more eastward solution,
weighted toward the GFS. This track would allow for the low to
track into Prince William Sound before the low and its front move
onshore early Wednesday as the associated upper-level wave moves
across Southcentral. This track would result in a faster decrease
in southeast winds, with winds becoming northerly in the wake of
the low and snow filling back in across Cook Inlet north to the
Mat Valley. In fact, this track would likely keep snow over the
western Kenai through Tuesday, with snow amounts of 6" or more not
out of the question. Similar amounts are also likely for the
Susitna Valley and Turnagain Pass with lesser amounts for
Anchorage and the Mat Valley. Several inches of snow are also
likely from Valdez north into the Copper River Basin as the low
lifts north.

By Wednesday, the precipitation will become more showery as colder
air aloft moves back in. A southerly flow near the surface may
allow temperatures along the coast to push above freezing,
resulting in a mix of rain and snow showers. Various shortwaves
moving through the region may also allow for more organized snow
showers across Cook Inlet and into the Mat-Su through Wednesday,
resulting in the potential for additional snow accumulations.

-TM

&&

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

KEY MESSAGES...

1) A High Wind Warning is in effect for Adak and Atka, and a Wind
Advisory for Unalaska. Winds also approach 75 mph for the Pribilof
Islands.

2) Parts of Southwest Alaska (mainly along the coast) can expect
to see heavy snow and areas of blowing snow/blizzard conditions.

3) Gusty winds and snow/rain showers will linger through midweek
across Southwest Alaska, the Bering Sea, and Aleutian Islands as
a strong low slowly weakens in the Bering Sea.

Discussion:

With yesterday's 968 mb low exiting towards Russia, the main story
through Wednesday will be a strong, 960 mb low that strengthens to
around 940 mb as it moves into the Bering Sea through today. The
overall hazards remain largely unchanged, but shifts in the timing
and trajectory of this low have led to some adjustments with the
forecast, with continued changes likely in forthcoming forecast
packages.

First, the wind threat: the forecast looks fairly on track for the
Central Aleutians, though forecast max wind gusts have increased.
The question will be whether Unalaska or the Pribilof Islands
could also see a period of 75+ mph winds as the low begins to
occlude early Tuesday morning. The latest models have trended the
low further north, which means a greater threat for the Pribilof
Islands, and a trend towards lower winds for Unalaska. However,
there is still some model disagreement. The other question will be
whether the High Wind Warning or Wind Advisory will need to be
extended. With the low remaining fairly strong as it occludes in
the Bering Sea, sustained winds will likely remain at gale force
through Wednesday for much of the Bering Sea. As a result, a
strong trough rounding the low could be enough to bring another
surge of Warning or Advisory level winds to the Aleutian Islands
on Wednesday.

Next, the snow and blowing snow threat: the biggest change with
the overnight package has been to upgrade the Winter Storm Watch
to a Blizzard Warning for the Kuskokwim Delta coast and Nunivak
Island. Confidence is fairly high that there will be a period of
blizzard conditions due to antecedent cold air currently in place
over the Kuskokwim Delta. Additionally, winds in Toksook Bay tend
to be much stronger than forecast when winds are easterly, so it's
likely that the ingredients of snow, cold temperatures, and gusty
winds will be sufficient to produce blizzard conditions.
The lingering question for the snow/blowing snow/blizzard Warnings
and Advisories currently in affect across Southwest Alaska and the
Pribilof Islands will be when to expire or cancel the products.
The latest models are trending towards a quicker-moving front,
which means that forecast snow amounts have dropped. In addition,
if this model trend holds, this could mean that the Advisories and
Warnings could be trimmed and ended earlier.

Finally, models have been trending towards stronger onshore winds
for the Kuskokwim Delta from Tuesday into Wednesday. Though this
would likely lead to high surf and/or coastal flooding in the warm
season, there is a question of whether the sea ice will be strong
enough to completely eliminate the threat of any coastal issues.
Right now, the potential for minor high surf or coastal flooding
cannot be ruled out, but it's hard to determine what impacts may
look like given the protective effects of the sea ice.

-KC

&&

.LONG TERM FORECAST (Days 4 through 7 - Wednesday through
Saturday)...

Starting off the long term forecast on Wednesday lies a strong
low in the Eastern Bering. This low is expected to bring gale to
storm force winds to the Aleutians Islands and the Pribilof
Islands. Precipitation from the low is expected to be mostly
snowfall due to a cooler air mass wrapping around the low. Blowing
snow from the gusty winds and snowfall could reduce visibility.
Southcentral will be less active, but lingering snowfall from a
previous low is possible. Thursday has the low moving onshore
bringing snowfall to the mainland and gusty winds to the coast.
With this, winds and precipitation in the Bering will diminish.
However, a strong front from a Kamchatka low pushes into the
Western Aleutians, making its way eastward and pushing onshore by
Friday. This front will bring another round of gusty winds to the
Aleutians, but the airmass will be warmer due to southerly flow,
so rain or a rain/snow are the more likely precipitation types.
However, the Southwest Mainland will remain cold enough for snow
once the front pushes onshore on Friday. Meanwhile, shortwaves
moving through Southcentral could allow for some snowfall, but
this is uncertain at this point in time.

Uncertainty arises on Saturday with the potential for smaller
lows to move through the Bering. These would up winds and
precipitation chances for wherever they move over. Uncertainty for
Southcentral is a little better, with a low forming somewhere in
the northern Gulf, allowing for snowfall for the coast and
potentially inland as well. The picture will become more clear
overtime as guidance gets a better feel for the forecast.

-JAR

&&

.AVIATION...

PANC...Primarily MVFR conditions with periods of IFR conditions
possible. Light snow may linger over the terminal until 21Z.
Clearing skies through the evening may lead to favorable
conditions for fog development overnight. Light northerly winds
will persist.

&&