Gale Warning 332, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
543 AM AKDT Wed Apr 23 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Wednesday through Friday Night)...

Unsettled weather will persist through Friday as a mature low
continues its track across the southern Gulf of Alaska. With the
system and its attendant front remaining primarily over water,
the most significant impacts will be felt by coastal communities
and mariners. Mainland Southcentral Alaska will mostly experience
light winds and scattered showers.

Satellite imagery shows a mature extratropical cyclone, analyzed at
997mb and near peak intensity, drifting northward across the Gulf of
Alaska. Ahead and to the north of this cyclone, mid- and upper-level
cloud cover continues to spread north into Southcentral Alaska which
in turn has helped to moderate temperatures overnight into early
this morning. Radar imagery shows the typical instability-driven
shower activity across the Northern Gulf, with an occasional cell
pushing onshore into the Kenai and Chugach Mountains amid deep
easterly flow. Widespread and heavier precipitation is focused along
the occluded front of the aforementioned cyclone will rotate into
the coast later today, accompanied by an offshore barrier jet, which
is expected to strengthen to high-end small craft winds.

Precipitation will primarily be confined to the coast today, though
diurnal heating leading to instability coincident with the timing of
a shortwave trough should result in some showers across the Copper
River Basin, particularly in the surrounding higher terrain of the
Wrangells and eastern Talkeetnas.

Thursday and Friday will be fairly similar to Saturday with the Gulf
cyclone gradually weakening as it drifts northeast in the direction
of Yakutat. Precipitation will remain confined to coastal areas,
with some chance in the higher terrain surrounding the Copper River
Basin. The best chance for precipitation in Anchorage and on the
west side of the Kenai/Chugach/Talkeetnas would come from a
shortwave trough rotating through Thursday afternoon, but chances
remain low due to lack of support, with higher probabilities across
the adjacent mountains where instability and perhaps some very
modest upslope may aid in precipitation coverage.

-Brown

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3)...

A ridge of high pressure has formed over the Central Bering and
is approaching the Southwest coast. Lingering precipitation is
expected to quickly conclude this morning, as the high pressure
facilitates clearer skies, drier conditions, and warmer
temperatures over the next few days. Periods of stratus and fog
may form during the nighttime hours.

A North Pacific low in the western Bering Sea pushes its front
eastward across the Aleutian chain today. Widespread gales will
weaken between the Pribilof Islands and the western mainland just
after midnight early Thursday morning. Precipitation from this
system will spread eastward across Unalaska Wednesday afternoon,
the Pribilof Island and Alaska Peninsula Thursday morning, and the
Southwest mainland by Thursday afternoon. Widespread rain and
snow will be possible across Southwest Alaska through the weekend.

&&

.LONG TERM FORECAST (Days 4 through 7/Saturday through Tuesday)...

The long term continues to be characterized by broad upper level
troughing over the Bering, as a series of upper lows stretch from
Eastern Siberia to Northwest Alaska to the Southern Bering for the
beginning of the period. A weakening ridge over Southcentral to
begin the weekend will quickly be pushed off to the east as the
upper low becomes more organized and consolidates in the Southern
Bering, rotating multiple rounds of shortwave energy across the
Alaska Peninsula and into the Gulf.

Generally unsettled and showery weather can be expected across
the Bering, Aleutian Chain, and Southwest Alaska through the
weekend as a surface low tracking into the Gulf may linger some
light precipitation across the region, with locally moderate
rainfall possible along the AKPen. As the system pivots eastwards,
southeasterly flow in the Gulf will drive mainly upslope-driven
precipitation to Kodiak Island and along the northern Gulf Coast
into early next week. An upstream surface low and its accompanying
front lifting out of the North Pacific reinforces another chance
for rain across the Aleutians as it skirts to the south of the
island chain early next week. By the end of the forecast period, a
lack of model agreement leads to decreasing confidence on the
evolution of another potential storm in the Gulf for Tuesday.
Though some uncertainty remains on the overall strength of the
system and eastward extent of precipitation, favored ensemble runs
suggest another potential round of precipitation along the AKPen
and northern Gulf coast.

&&

.AVIATION...

PANC...Light northerly winds and mostly VFR conditions will
prevail through the TAF period. There is a possibility that
ceilings could briefly drop to MVFR if a shower moves over the
terminal before precipitation chances end sometime late Wednesday
morning.

&&