310
FXAK68 PAFC 070303
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
703 PM AKDT Fri Jun 6 2025

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

Short lived, transient upper level ridging will generally yield a
pleasant afternoon and evening for most of Southcentral. Upper
level clouds are already starting to stream overhead for much of
Southcentral out ahead of a triple point low situated southeast of
Kodiak, with its occluded portion of the boundary beginning to
move northward towards the Gulf coast. Surface level coastal
ridging will build and enhance as the low pressure system draws
closer to the coast starting this evening into Saturday morning.
Southerly to southeasterly flow will induce wind for all favorable
gap regions this afternoon and evening, including the Turnagain
Arm, Knik Arm, and Copper River Basin. The most likely areas for
any isolated thunderstorm development this evening will be for the
Wrangells and Copper River Basin due to a lifting upper level
shortwave moving out of the area. Although there is daytime
heating for the Mat-Su, only very isolated convection is likely to
form as there is minimal mesoscale/synoptic support. Storm force
wind gusts ahead of the front are possible for Kayak Island
Saturday, while gale force winds will extend around the outer most
coastline, impacting the Barren Islands, and to a lesser extent,
the Shelikof Strait and Cook Inlet.

As the low moves closer to the coast, any ridging will break
down, allowing for gap winds to begin to relax as wind direction
and pressure orientation changes, allowing wind to be down-inlet.
Most of the operational models agree that the front arrives to the
immediate Southcentral coast with a band of precipitation by
midday Saturday to Saturday afternoon. One favorable location for
elevated QPF values will the northeastern facing slopes of the
Kenai Mountains due to east- northeasterly winds creating
orographic lift. One area that bears watching late Saturday is
Cook Inlet, where winds could still be small craft criteria after
the frontal passage. As the front progresses farther inland and
weakens, it also interacts with a deep upper level low digging
down from northwestern AK, further enhancing rainfall by
steepening lapse rates for much of Southcentral. The upper level
support could offset the downsloping wind component that will be
associated with the weakening front. Models are struggling with
the general degree of forward momentum of the upper low and any
orientation of trough axes that would be associated with it.
However, in some form, rain chances will likely persist through
the first part of the work week.


-AM

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
(Days 1 through 3: This afternoon through Monday evening)...

Unsettled weather continues through the weekend as several storms
move across the forecast area. For Southwest Alaska, a North
Pacific low will graze the region as it moves near Kodiak Island
and into the Gulf. With the low center quite distant from
Southwest Alaska, the worst conditions will remain outside the
forecast area. Have continued to leaned towards higher winds,
with gales forecast between Kodiak Island, Chignik, and south of
the Shumagin Islands. Expect breezy conditions as the low moves
through, then a potential for below-average temperatures as an
upper low nudging in from the north brings in a colder and drier
air mass. Have kept temperatures in line from the previous
forecast, with the thinking that clearer skies and daytime heating
could mitigate some of the cold air advection.

Shifting gears to the Bering Sea and Aleutian Islands, the main
player for now will continue to be the ridge, which is currently
located over the Western and Central Bering Sea. As seen on
satellite imagery, much of the Bering Sea is blanketed in stratus
courtesy of this ridge, with some fog around the Pribilof
Islands. The stratus and fog will continue until the ridge
erodes, which will occur gradually over the coming days as several
waves run up against the ridge`s western flank. Of note will be a
strengthening upper level shortwave and its associated surface low
moving into the Western Bering from Sunday evening into Monday
evening, which will bring the potential for a broad swath of 25+
kt winds, a small corridor of gale-force winds, and moderate to
heavy precipitation mostly across the Aleutian Chain. Light rain
is possible for the Pribilof Islands Monday afternoon into the
evening as the low works further east with precipitation making it
to the southwestern mainland for Tuesday.

-Chen/DAN

&&


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

The upper level weather pattern smooths out and changes to a more
organized set of waves through the forecast period. A closed
upper low exits Southwestern Alaska across the Gulf of Alaska to
near Queen Victoria Island by the end of the week. After the
passage of some moderately strong shortwaves, an extended trough
forms over most of the Bering from the Arctic across the Chukotsk
Peninsula to the North Pacific. A fairly well clustered blend of
GFS / ECMWF UKMET and Canadian models carry the larger features,
with the ECMWF taking over towards the weekend.

Scattered showers with possible thunderstorms over the Southern
Interior, mostly South of the Alaska Range continues through
Friday. A well developed surface low and front over the Central
Aleutians and Bering spread moderate rain across the region into
Southwest Alaska, diminishing Thursday over Western Alaska. A
second low and front follow on its heels over the Western
Aleutians and Bering, diminishing late Wednesday. A strong North
Pacific low and front brings moderate to heavy rain starting in
the Western Aleutians Thursday, and marching across to Southwest
Alaska, the Alaska Peninsula and Kodiak Island for Friday.

- Kutz

&&

.AVIATION...

PANC...VFR conditions will continue through Saturday morning.
Gusty southeasterly winds out of Turnagain Arm will continue
through around midnight with gusts up to 40 mph possible between
6 PM and 10 PM. Winds are then expected to diminish quickly,
becoming light and variable between midnight and 4 AM. A period
of LLWS is possible during this time as winds aloft remain out of
the southeast for slightly longer. Winds will then become
northerly for Saturday as rain and lower ceiling move over the
terminal.

&&


$$