Gale Warning 313, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
436 PM AKDT Thu Mar 28 2024

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

Two storms will impact Southcentral through the weekend.  The
first storm will impact Southcentral this evening through
tomorrow afternoon. Snow levels will rise ahead of the
approaching precipitation resulting in a quick period of rain/snow
showers changing quickly to all rain for the event for coastal
areas. High mountain locations will stay as all snow though.
Wind gusts at high elevations and passes/gap areas, such as the
Anchorage Hillside, Thompson Pass and Turnagain Arm, will range
from 50 to 60 mph with gusts to 75 mph are expected. Elsewhere,
including Anchorage Bowl, sustained winds ranging from 25 to 35
mph gusting to 55 mph.

A more potent storm will move through Southcentral Saturday and
Sunday bringing rain, snow and strong winds. Currently, this late
weekend storm is favored to move through western Alaska or up
Cook Inlet instead of moving through the North Pacific, with its
its front stretching northward to Prince William Sound.
Southeasterly to southerly winds will bring moisture to coastal
areas from Kodiak Island to Cordova resulting in rain and snow
Saturday and Sunday. Snow levels will range from 800 to 1000 feet
creating mostly rain at coastal areas with snow at higher
elevations. Passes and mountains should remain as all snow during
the event. Colder air Saturday evening into dawn Sunday could work
its way down to lower elevations creating a rain/snow before
ending as snow showers in the afternoon. In addition to the
precipitation, sustained winds ranging from 50 to 60 mph with
gusts to 70 mph are possible in Thompson Pass, Anchorage Hillside,
and Turnagain Arm during the storm.

-DJ

&&

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

Active weather continues across Southwest Alaska on Friday as an
upper level Fujiwhara dance takes place in the northern Bering.
The low which has been in place over Saint Lawrence Island for the
last few days will slide into the Gulf of Anadyr then rotate
south, changing places with a North Pacific low consolidating as
it crosses the central Aleutian Chain into the Bering Sea, and
reaching the Kuskokwim River Delta by Friday afternoon.

A frontal boundary along the leading edge of this low is bringing
gusty winds and moderate rain to the eastern Aleutians, Pribilof
Islands, and Alaska Peninsula. The trailing low will bring
widespread gales (>34 kts) and areas of storm-force (>48 kts)
gusts. Blowing snow and blizzard conditions might be possible
along the Southwest coast Friday night into Saturday. The AKPen
may start with rain and transition to snow, but elsewhere along
the northern Bristol Bay coast and Kuskokwim Delta, can expect 2-3
inches of heavy snow, tapering off Saturday morning. The highest
amounts (5-6 inches) are likely for the northern side of Bristol
bay from Dillingham to Nunivak Island. A second round will bring
up to 2 inches of additional snow to the greater Bristol Bay area,
Kuskokwim Delta, and lower Kuskokwim River Valley Saturday night
through Sunday.

Good confidence exists that the entire domain will have a brief
break from precipitation on Monday, before a North Pacific system
moves across the Bering Sea and into the area on Tuesday.

&&

.LONG TERM FORECAST (Days 4 through 7: Monday through Thursday)...

A deep upper level trough over the Eastern Bering extends from
the Arctic to the North Pacific drives across the state of Alaska
through Wednesday. While the confidence of movement of the trough
is good, a number of shortwaves traveling through the pattern
increase the uncertainty in the associated weather, particularly
across Southern Alaska as several North Pacific systems add to the
mix. Deep cloudiness and periods of snow moves across the
Interior Sunday and Monday, diminishing Tuesday. Over the
Southcentral areas, the first well developed surface low marches
onshore near the Canadian Border late Monday, with gusty winds and
mostly rain spreading inland and Westward towards Prince William
Sound. Gusty outflow winds with areas of gale force winds blows
across Kamishak Bay and the Barren Islands and around Sitkinak
late Monday, diminishing Tuesday. A weak upper ridge moves into
the Interior for Thursday.

Another somewhat deep trough moves into the Bering Wednesday.
Most of the energy is deflected over the Southern Aleutians and
Bering. A developing North Pacific surface low pushes its way
across the Western Aleutians on its way just North of the
Pribilofs by Thursday. Gusty winds move over the Aleutians while
areas of gales surround the low in the Western Bering, all
diminishing Thursday. Locally heavy rainfall accompany the front
as it moves Eastward into the Pribilofs, Alaska Peninsula and
Southwest Alaska by Thursday. Another round of locally heavy rain
comes into the Western Aleutians for Thursday.

Kutz

&&

.AVIATION...

PANC...VFR conditions and light winds will persist through
tonight. There will still be a window for low ceilings in MVFR
range this evening, but drying southeast flow developing late
tonight should prevent prolonged periods of low stratus from
persisting into the morning hours tomorrow. Southeast winds aloft
will continue to strengthen during the day on Thursday. Strong
surface winds will likely stay mostly south of the terminal at the
surface through early Friday afternoon, with mainly a threat for
LLWS expected starting Friday morning.

&&