Gale Warning 286, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
1148 PM AKDT Tue Mar 12 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: This
afternoon through Friday afternoon)...

From Wednesday afternoon through early Thursday afternoon, the
next significant low will deepen and move across the Gulf towards
Eastern Alaska. Unfortunately, not much insight has been gained
with this system as model guidance remains split between two
camps. Only with the latest runs have models looked like they
might be converging towards a solution. Overall, this means that
there is lower forecast confidence for this time period. It's
likely that forecast winds are a bit underdone as we try to handle
model differences, so keep an eye out for increasing winds
(especially over marine areas) as model agreement and forecast
confidence steadily improve. Improving model agreement will also
help us get a better handle on the potential for blowing snow in
Thompson Pass from Wednesday night through Thursday morning, which
is the primary hazard we'll be monitoring in this time period.
Though forecast confidence is lower in the exact details, we have
moderate to high confidence that the low track will remain mostly
over the Eastern Gulf. This means precipitation will likely be
limited to Prince William Sound and the Copper River Basin, and
northerly flow along the west side of the front will likely keep
precipitation as all snow.

From Thursday afternoon through Friday afternoon, a lull in the
weather as the low weakens and moves inland. Much more active
weather expected by Friday evening as a distant North Pacific low
pushes its front east to west across Southcentral, bringing
abundant moisture and stronger winds.

- KC

&&

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

A deep trough over Southwest Alaska continues mostly dry
conditions over the next couple of days with cold arctic air
remaining in place. Temperatures, however, are expected to slowly
moderate throughout the next few days as cold air advection ceases
and some more cloud cover moves in. A large North Pacific low
extending its front over the central Aleutians will slowly slide
south and east through tomorrow, but notable cold air advection is
expected to continue snow showers over much of the Aleutians and
the Pribilofs over the next few days.

A front extending off a robust low just southeast of Kamchatka
will then push over the Western Aleutians late Wednesday night
through Thursday morning, producing widespread gale force winds
ahead of it. Precipitation may briefly start as snow, but will
quickly begin to mix with rain or fully changeover to rain through
Friday. A changeover back to mix or snow is possible for western
areas as the low continues to occlude and cold air wraps back in
behind the low on Friday.

-ME

&&

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

The upper level ridge over the Bering continues a slow transition
into the Russian Far East into the new week. The Arctic trough
that extends over the Western Interior stretches into the Bering
behind the departing ridge, with a closed center over the Southern
Bering by the end of forecast period. A second upper level ridge
moving into the Eastern Interior slows its progress through Monday
before building across the state with help from a shortwave ridge
from the West through Tuesday. With some shortwave support of
North Pacific surface systems and active weather is expected
across the Southern portions of Alaska through the forecast.

Easterly gusty winds associated with a decaying front across the
Aleutians stretch over the Western Bering through Sunday. A well
developed North Pacific low moves over the Aleutians takes over
for Sunday, spreading its influence across the Aleutians and
Alaska Peninsula into Southwest Alaska through Tuesday. 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 as the low moving along the front makes
landfall on Sunday. Warming temperatures with widespread
precipitation are expected from the Alaska Peninsula over Kodiak
Island and all along the North Gulf Coast, diminishing West to
East. Rainy conditions, locally heavy, spread inland from the
Eastern Kenai Peninsula, Prince William Sound across the rest of
the Southcentral coasts, with snow expected further North. A
second North Pacific low brings another round of precipitation to
the North Gulf Coast for Monday through Tuesday.

Kutz

&&

.AVIATION...

PANC...VFR conditions and light winds will persist.

&&

Preliminary Local Storm Report
National Weather Service Anchorage AK
1020 PM AKDT Tue Mar 12 2024

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0205 PM     Snow             Alyeska                 60.96N 149.10W
03/12/2024  M24.0 inch       Anchorage          AK   Public

            24 inches reported at the top of Alyeska.

&&

MJB