Gale Warning 284, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
458 AM AKDT Tue Mar 12 2024

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

Winter weather continues for the Kenai Peninsula and areas along the
Prince William Sound while much of the rest of southcentral Alaska
remains on the quiet side, as far as weather is concerned. Satellite
imagery shows upper-level troughing remains established along an
axis from approximately western AK through Kodiak Island. A well-
defined vort maxima and associated surface low is currently moving
towards the SE coast of the Kenai Peninsula, with much of the
coastal area in moist southeast flow.

Webcams, Snotel stations, as well as highway reports suggest about 1
to 2 feet of snow has fallen in locations such as Alyeska, Portage,
and Turnagain Pass... with about half that much further south such
as towards Summit Lake and Seward. Snow will continue in these areas
today as the aforementioned low pivots into the Kenai Peninsula.
Snow rates in excess of 1"/hour will be possible at times this
morning, which may lead to reduced visibility and difficulty during
the morning commute. Slightly warmer temperatures today may reduce
snow-liquid ratios and overall accumulation at locations near sea
level such as Girdwood, eastern Turnagain Arm, and Whittier. Any
rain mix should be relatively short-lived as colder air wraps back
into the Peninsula by late afternoon.

Cold northwest flow wrapping on the backside of the low will keep
snow activity focused in areas along the southwest Kenai such as
Anchor Point and Homer southward towards Seldovia. Recent model
trends suggest Seldovia and nearby south/west coastal Kenai will
receive gusty winds and snow for much of the day. Reduced
visibility is likely, along with upwards of around a foot of
snowfall.

Snow across the Kenai Peninsula will taper off Tuesday night, though
cool and moist easterly flow will aid in lingering upsloping snow
for much of the coastal Kenai and western Chugach.

The next significant low is expected to deepen and move into the
Gulf of Alaska late Wednesday into Thursday. There still remains
pretty large model spread on placement, but the majority of guidance
suggests any precipitation of significance will be from about
Cordova eastward. A more eastern track would result in light snow
for Cordova, while a more western track could mean a heavy rain/snow
mix. Model spread remains large, but the majority of the guidance
favors the former solution at this time.

-Brown

&&

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

Mostly dry conditions continue across Southwest Alaska over the
next couple of days. Cold Arctic air continues to filter south
across the region, keeping temperatures in the single digits or
low teens today and tomorrow. The Wind Chill Advisory for the
Kuskokwim Delta will remain in effect through this morning, with
the coldest temperatures early this morning. A bit of a warming
trend is expected later in the week as cloud cover rolls back in.

Conditions across the Bering Sea and Aleutians are not all that
different. An area of gale force winds will continue along the
Central Aleutians as a low passes to the south. With it, snow is
likely to continue through this morning in Adak and Atka before
tapering off. A front extending off a low developing near
Kamchatka will move over the Western Aleutians late Wednesday
night/early Thursday morning and will bring active weather to the
area.

&&

.LONG TERM FORECAST (Days 4 through 7) Friday through Monday...

The weather pattern over the region will reverse by the end of
the forecast period. The upper level ridge over the Bering makes a
slow transition into the Russian Far East through the weekend.
The Arctic trough that extends over the Western Interior stretches
into the Bering behind the departing ridge. A second upper level
ridge moving out of Canada into the Eastern Interior continues to
spread over the state, with help from a shortwave ridge from the
West. Add in the influence of shortwave support of North Pacific
surface systems and active weather is expected across the Southern
portions of Alaska through the forecast.

A South Kamchatka low extends a decaying front across the
Aleutians through Saturday. Easterly gusty winds stretch over the
Western Bering through Sunday. A well developed North Pacific low
moves over the Aleutians taking over for Sunday, spreading its
influence across the Aleutians and Alaska Peninsula into Southwest
Alaska by Monday. Mostly rain, locally heavy, moves Eastward
through the period. Gusty winds accompany the low, with areas of
gales South of the Aleutians.

In the East, a moderate North Pacific low extends a front into
the Gulf of Alaska for Friday. Warming temperatures with
widespread precipitation are expected from the Alaska Peninsula
over Kodiak Island and all along the North Gulf Coast, diminishing
Sunday. Rainy conditions, locally heavy, spread inland from the
coasts, but snow remains across the Anchorage and Mat-su Valleys
and North. A second North Pacific low brings another round of
precipitation to the North Gulf Coast for Monday.

Kutz

&&

.AVIATION...

PANC...VFR conditions will prevail through this evening with wind
gusts ranging from 15 to 20 kts this afternoon. Isolated snow
showers are possible in the evening hours. VFR conditions are
expected tomorrow.

&&