Gale Warning 316, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
504 PM AKDT Fri Mar 29 2024

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

A low will move into Cook Inlet tomorrow bringing much more
varied precipitation and winds across the Kenai Peninsula,
Anchorage Bowl, the Copper River Basin and the Mat-Su Valley.
Southeasterly to easterly winds will increase late Saturday
morning through the Turnagain Arm and the Anchorage Hillside with
gusts up to 75 mph. Wind gusts up to 55 mph are expected at lower
elevations through Saturday evening. Snow levels will remain above
1000 feet Saturday resulting in continued high elevation snow
accumulation. Winds, in addition to snow, will also be strong in
the Copper River Basin, including Thompson Pass. Total snow
accumulations ranging from 10 to 20 inches and wind gusts up to 40
mph by late Sunday morning are likely.

Overnight Saturday, wind direction will shift to a more southerly
to southwesterly flow as the low moves over Cook Inlet. This
could result in sustained winds ranging from 25 to 35 mph with
gusts up to 55 mph beginning Sunday morning in the Kenai
Peninsula. In addition to this wind shift, precipitation and
cooler air will arrive causing snow and blowing snow for most of
western and southern Kenai Peninsula; this includes Homer north to
Kenai through most of Sunday. These southerly winds and a period
of snow will reach lower elevation areas of Anchorage late Sunday
morning with wind gusts ranging from 35 to 45 mph. Snow and
blowing snow will accompany the wind direction change in the Kenai
Peninsula.

DJ

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA, the BERING SEA and the
ALEUTIANS (Days 1 through 3: Friday through Tuesday)...

A large upper-level trough remains parked over the Bering Sea,
with its axis stretching from the Southwest Alaskan coast to the
central Aleutians. This longwave trough is dominated by two upper-
level lows. The first is lifting from south of the Alaska
Peninsula to the Alaskan Interior overnight, while the second
dives southeast from the central Bering, replacing its predecessor
at the base of the trough by Saturday morning.

The first upper-level low will continue to track northeast as its
attendant surface low moves inland. Strong winds will wrap
around the surface low, especially along the backside of the low
where colder, more unstable air will work in. Copious moisture
will also accompany this system, with widespread snow likely for
much of Southwest Alaska. Communities will see up to 6 inches of
new snow Saturday into Sunday along with very strong winds both
ahead of and in the wake of the low.

Over the Bering, northerly flow will bring colder air and snow
showers from west of the Pribilofs south to the central Aleutians.
These features will bring much colder air across the eastern half
of the Bering and western half of the state by Tuesday.

&&

.LONG TERM FORECAST (Days 4 through 7: Tuesday through Friday)...

The upper air pattern increases its activity during the next week
as a deep shortwave extending from the Arctic through Interior
Alaska into the North Pacific moves into Canada by late Wednesday.
Most of the energy runs along the Southern portions of Alaska
through the week. A moderate ridge follows right behind and exits
Alaska for Friday. Another shortwave slips into Western Alaska by
the end of the forecast period. Further West, a more moderate
closed low pulls into the Central Bering. Greatest confidence in
the early forecast models is supported by deterministic model
combinations, but becomes more uncertain by the end of the week
between the stronger Western-Central Bering low and multiple
weaker shortwaves rotating across the state.

On the Alaska surface chart, a well developed Western Aleutian
low extends a front across the Bering. This front brings sustained
strong Southwesterly winds into Southwestern Alaska and the
Alaska Peninsula for Tuesday. Areas of coastal flooding and beach
erosion are possible from Bristol Bay to the Yukon Delta. High end
gale force winds over the Western Aleutians Tuesday, breaks down
to areas of gale force winds across the Aleutians and Bering, and
diminishing as the low tracks across the Northern Bering.
Widespread rainfall is expected along the Aleutians, AKPEN and
Southwest Alaska with the front. Warmer temperatures spread inland
through the period. Strong winds continue over Kodiak Island into
the Gulf of Alaska and the Southcentral zones into the Copper
River Basin through Friday. Locally heavy rainfall moves over
Kodiak Island late Wednesday into Friday, and spreads to the East
through the forecast period.

Kutz

&&

.AVIATION...

PANC...VFR conditions thru tonight. Winds this evening will mainly
be gusty and southeasterly but may switch to west or northwest at
times due to the Turnagain Arm jet either being over the airport,
or pulling more to the west which puts PANC into the eddy of these
stronger winds. A strong low arriving the latter half of
Saturday. Any precipitation on Friday should be light, with the
best shot of a rain/snow mix from noon thru the evening hours, and
perhaps a better chance for precip Saturday morning.

&&