Gale Warning 251, NWS Anchorage, AK

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

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

Satellite shows this weekend's storm moving into the North
Pacific near Kodiak Island. A slightly more eastward track has
been noted today. The storm will continue to progress northward
through tomorrow afternoon bringing strong winds and precipitation
across the Southcentral and the Prince William Sound areas. Wind
directions will shift from southeast to southerly along the
eastern coastlines of Kodiak Island and the Kenai Peninsula this
evening through dawn tomorrow. Wind gusts will briefly range from
40 mp to 50 mph with a more southerly direction in Seward and
Kodiak for example. Precipitation will continue to change from
snow to rain and a mix of rain and snow through this evening.
Overnight and tomorrow morning, a return to snow is likely with
accumulations of a trace to an inch for many area of the Kenai
Peninsula, Anchorage Bowl and Mat-Su Valley as colder air begins
to filter into the region on the backside of the low. Higher
elevations of the Kenai Peninsula, Prince William Sound, the
Copper River Basin and Thompson Pass will remain all snow during
the event with several inches expected. Winter weather advisories
remain in effect for these areas through tomorrow afternoon.
Southeasterly to Easterly wind direction will increase this
evening across Southcentral as a the low departs in to the
Interior and cold air rushes southward through the region. Wind
gusts ranging from 45 to 55 mph are expected in lower elevated
areas with gusts up to 75 mph in higher elevations such as the
Anchorage Hillside into late Sunday morning. With the push of
colder air up the Cook Inlet, a brief period of southerly to
southwesterly winds will bring higher gusts into West Anchorage
northward up the Knik Arm mid-morning through late morning
tomorrow.

This active pattern will continue through mid-week as a series of
lows move through the region.

-DJ

&&

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

The forecast remains on track for impactful weather to continue
for mainland Southwest Alaska and across portions of the Alaska
Peninsula (AKPEN) through late tonight into Sunday morning.
Currently, a strong low pressure over southern Kodiak Island
continues to lift northeastward through Shelikof Strait and
towards Cook Inlet. Blizzard Conditions are observed over Port
Heiden and Pilot Point with snow for coastal and portions of
interior Bristol Bay (Koliganek and New Stuyahok), the Kuskokwim
Delta, and the Lower Kuskokwim Valley. Portions of the southern
AKPEN have also seen gusty winds, snow, and reduced visibilities.
As such, Winter Weather Products remain out for mainland Southwest
and the AKPEN with the AKPEN product ending at 10PM tonight. The
other products remain into Sunday morning.

Snow showers will persist into Southwest the rest of Sunday and
into Monday as an Arctic trough digs southward over the area. This
will cause temperatures to drop into the teens and single digits
for highs Monday over mainland Southwest with readings in the 20s
for the AKPEN. Overnight low temperatures Sunday night and Monday
night will get down to the negative single digits for mainland
Southwest while the AKPEN sees mostly teens with singles digits
for the northern AKPEN. Another story with this cold air push will
be the potential for Extreme Freezing Spray along the ice edge
Sunday night into early next week.

Further west, a weak Kamchatka low sends its front through the
Aleutian Chain Sunday evening through Tuesday morning before it
merges with a second and stronger low's front. With this initial
front, expect gusty conditions along the Chain and Pribilof
Islands with snow changing to rain as warm air works in. There is
a possibility that the Pribilof Islands could see a period of
blowing snow with reduced visibilities Monday evening before the
warm air works in overnight. The second and stronger low
approaches the Western Aleutians Monday evening bringing more
rain/snow mix and changing over to rain. As the system occludes
Tuesday morning, cold air wraps in and changes precipitation back
to snow. Precipitation will mostly be in the form of rain along
the rest of the Chain. The wind field looks quite impressive with
this system as it reaches the Western Aleutians as a storm-force
low with hurricane-force gusts through Tuesday. Widespread gales
are expected across most the of Bering Sea with pockets of storm-
force winds on the Pacific side of the Chain.

-DAN

&&

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

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.

-KM

&&

.AVIATION...

PANC...A frontal system will bring periodic rain/snow to the
terminal this evening with general VRF conditions lowering to MVFR
in conjunction with precipitation. Northwesterly winds near the
surface, coupled with increasing southeasterly winds aloft an out
ahead of the front, will allow LLWS to persist into the late
evening hours. As the front and parent surface low lift north of
Anchorage around midnight or very early Sunday morning, expect
precipitation to fill back in with rain changing to snow. The
wind flow will shift to the southwest and increase with gusts
around 50 mph over the terminal not out of the question. Winds
will slowly diminish through Sunday as precipitation tapers off.

-TM

&&