High Wind Warning 22, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
1258 PM AKDT Wed Oct 23 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Wednesday evening
through Friday)... Extending south of the Alaska Range, weak
embedded shortwaves are expected to move quickly from west to east
across Southcentral for roughly the next 24 hours. The result
will be persistent snow showers for higher elevations, especially
with upslope flow along terrain. Meanwhile, cold air advection is
expected to initiate a cooling trend for Southcentral through the
rest of this week. As colder air arrives, on the developing
westerly flow aloft, winds will diminish across Cook Inlet but
increase for Whittier, Seward, and other gaps along the
Southcentral coast. Snow shower activity will likely diminish
through this afternoon for all locations with the exception of the
central Chugach and Wrangell Mountains. The next low arrives to
the western Gulf from the eastern Bering Thursday afternoon. Where
Kodiak was being downsloped by westerly winds, a front will shift
the pattern completely, bringing rain and southeast winds to the
Island for Thursday through Friday. The front lifts north later on
Thursday, spreading precipitation across the northern Gulf coast
and Prince William Sound. The surface low and front look to remain
far enough south to keep most of the precipitation closer to the
Gulf/Prince William Sound coastlines with northerly offshore flow
for much of Southcentral. Broad Pass, Matanuska Valley, Thompson
Pass, and other coastal gap locations could become gusty with
northerly winds starting Thursday and potentially lasting through
this weekend.

-TM/AP

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Wednesday evening through
Friday)...Westerly flow is bringing showers into the Kuskokwim
Valley today, as well as across the AKPEN. Showers are tapering
this afternoon and evening as the low level winds switch around to
northerly this evening as a powerful low shifts into Bristol Bay
tonight. This storm will reach "storm" force (50 knots) sustained
winds on the back of the low over W Bristol Bay. The low is
projected to track from Cape Newenham to King Salmon to the open
waters of the W Gulf of Alaska by Thu night. High pressure builds
in early Friday through Saturday.

Impacts to the Alaska Peninsula and SW AK with this storm
include:
* Strong north winds as the low moves across Bristol Bay into the
  Gulf, with winds gusting to 45 to 55 mph along the Bristol Bay
  coast, and gusts to 40 to 45 mph over the Kusko Delta coast.
  These winds peak Thu morning through Thu evening. Strong north
  winds are waning but continuing into Friday.
* Heavy rainfall over the AKPEN with the mixed rain/snow along the
  Bristol Bay coast from Dillingham and King Salmon northward,
  with locally heavy snow toward Lake Iliamna around Igiugig.
* Dry high pressure settles through Saturday, with only a slight
  chance for snow over the far Kuskokwim Delta coastline to
  Nunivak on Sat.

-Ahsenmacher

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Wednesday evening
through Friday)...A powerful storm force low will move from just
east of the Pribs late this evening to Bristol Bay by tonight and
early Thu morning. The storm force winds will impact the E
Aleutian Chain and the far W AKPEN with gusts as high as 70 mph
from Akutan to Pauloff Harbor to False Pass/King Cove. Gusts as
high as 65 mph will impact Sand Point and Perryville. Expect
heavy rainfall turning to mixed rain/snow squalls as the powerful
north winds blast across the region noted above. Winds diminish
Friday as high pressure builds in.

The next low to track will be a gale force front moving from 200
nm N of Shemya on Thu morning to Saint Matthew Island by Friday
and Friday night. The front approaches the Kusko Delta coastline
and Nunivak Island Sat morning with mixed rain/snow.

-Ahsenmacher

&&

.LONG TERM FORECAST (THURSDAY TO NEXT MONDAY)...A deepening low
in Bristol Bay Thursday moves over the AKPen and into the North
Pacific by Friday morning. During its southeastward progression,
southwest winds and increasing wave heights are likely along the
northern AKPen and portions of the Southwest AK coastlines. After
it crosses into the North Pacific Ocean, northerly storm force
winds through the Central and Eastern Aleutians are likely through
Friday afternoon. Elsewhere, high pressure in the North Pacific
south of Adak will progress southeastward Thursday as a front from
a Kamchatka Low moves through the Aleutians Saturday reaching the
Southwest coastline early next week. A second low begins to move
through the Bering Sea next Monday. A low crossing into the North
Pacific deepens as it progresses into the Gulf of Alaska this
weekend. During its southeastward travel through the Gulf,
increasing winds through Shelikof Strait, Kodiak Island and the
Kenai Peninsula can be expected. Confidence in its exact placement
is moderate with its strengthening and eastward progression
toward Southeastern Alaska. As the low strengthens and progresses
eastward, the possibility of increased gap winds return for Price
William Sound for the end of this weekend into early next week.
Elsewhere, as the high in the North Pacific moves to the
southeast, signals point toward a weak low forming and moving
northeastward along the Aleutians toward the Northern Gulf of
Alaska.

-TM/AP

&&

.AVIATION...PANC... VFR continues with winds becoming
northeasterly.

&&