Gale Warning 250, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
509 AM AKDT Sat Mar 30 2024

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

An active weather pattern continues over Southcentral with the
second and stronger low that is currently in the Northern Pacific
continuing to push north and east today. The low will be located
near Kodiak Island this afternoon and southern Cook Inlet this
evening. The low will split with some energy moving into PWS as
and the main low moving north into Cook Inlet and Susitna Valley
by Sunday morning.

Winds will increase this morning over the Anchorage Hillside and
Turnagain Arm with as a strong front pushes north into the
Northern Gulf. Expect southeast winds in the 40 to 50 mph range
with gusts to near 75 mph expected on the Anchorage Hillside and
Turnagain Arm while the Anchorage Bowl can expect southeast winds
of 25 to 35 mph with gusts to 55 mph as the front approaches
today. Expect a second round of strong winds to develop after
midnight tonight as the low sweeps north pushing in a colder
airmass and snowfall at sea level across the Cook Inlet Region
and Mat-Su Valley late this evening and into Sunday morning. The
High Wind Warning in effect for today has been extended into
Sunday morning with the second round of winds as the cold airmass
pushes north into Cook Inlet. Will have to monitor the potential
for snow and blowing snow late tonight and Sunday morning across
the Anchorage Bowl and the Mat-Su Valley where snow accumulations
of 1 to 3 inches are possible beginning late tonight and
continuing into Sunday. The front range of the Chugach mountains
including the Anchorage Hillside and Talkeetna Mountains
especially Hatcher Pass will likely see several inches of snow.
The combination of snow and blowing snow will reduce visibility in
these areas Saturday night and Sunday morning.

A Winter Weather Advisory has been issued for the Susitna Valley
from Talkeetna north where 5 to 12 inches of snow are expected
Saturday afternoon into Sunday afternoon. A Winter Weather
Advisory has also been issued for snow and blowing snow for the
Western Kenai Peninsula beginning Saturday afternoon and
continuing into Sunday morning where 1 to 4 inches of snow are
expected and combined with strong winds will cause visibility to
drop to one half mile or less at times. A Winter Weather Advisory
has been issued for Turnagain Pass where 6 to 12 inches of snow
are expected from late this morning to Sunday morning and combined
with winds gusting as high as 40 mph will produce visibilities
reduced to one half mile or less as times. Winter Weather
Advisories have been issued for Thompson Pass where 12 to 18
inches of snow are expected and combined with 40 mph wind gusts
will reduce visibility to one half mile or less at times. A Winter
Weather Advisory has been issued for the Copper River Basin from
Tonsina south where 10 to 15 inches of snow are expected from late
this morning into Sunday afternoon and combined with wind gusts
to 45 mph will reduce visibility to one half mile or less at
times.

And just in time for April Fools Day, A third but weaker low is
forecasted to move into the northern Gulf of Alaska and will
bring another round of strong winds and precipitation late Sunday
evening and into Monday.

-CC

&&

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

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 morning there is a surface low moving
inland near Nunivak and a second surface low south of the Shumagin
Islands. The low south of the chain will rapidly intensify an
impact southwest Alaska. Expect a tight pressure gradient over
much of the eastern Bering/Aleutians, Bristol Bay and the AKPEN.
On satellite imagery there is a deep fetch of moisture that spans
from the AKPEN to the Central Pacific Basin just west of Hawaii.
This moisture combined with the dynamics will result in a fresh
blanket of snow.  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 through the first half of Saturday. The
arrival of a front into PANC will introduce wind shear as well as
ceilings lowering to MVFR levels. A low confidence chance for
light rain exists this afternoon and evening. MVFR conditions
continue into Sunday with increasing southerly winds and
developing snow/blowing snow chances during the morning hours.

BL

&&

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
1148 AM AKDT Sat Mar 30 2024

AKZ171-311200-
Kodiak Island-
Including the city of Kodiak City
1148 AM AKDT Sat Mar 30 2024

...STRONG WINDS DEVELOPING LATE THIS AFTERNOON/EVENING FOR THE FAR
EASTERN ALASKA PENINSULA AND KODIAK ISLAND...

Southerly winds will increase south of Kodiak Island and out of
the northwest across the southern Alaska Peninsula this afternoon
as a strong storm system moves northwards towards Kodiak Island.
As the area of low pressure moves north of Kodiak, winds will
shift to the southwest, peaking this evening before gradually
decreasing through Sunday morning. Areas near Chignik and lower
elevations of Kodiak Island, including Kodiak City, could see wind
gusts up to 55 mph.