Gale Warning 566, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
513 AM AKDT Mon Sep 29 2025

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

Generally quiet weather can be expected for Monday and Tuesday
across Southcentral as high pressure spanning the region is
sandwiched between a departing low over the Gulf and a passing
trough to the north. Frost and fog will be possible this morning
and again Tuesday morning. Cool temperatures will prevail and
breezy conditions can be expected through typical gaps along the
Gulf and Prince William Sound coasts for today, diminishing
Tuesday. Mid to high clouds across the Susitna Valley and Copper
River Basin will be likely due to the trough to the north moving
from west to east today and tomorrow. A few light snow or
rain/snow showers will be possible Tuesday morning for areas along
the Tok Cut Off Rd.

Looking towards midweek, a front arrives to the western Gulf
early Wednesday morning and a surface low forms in the northern
Gulf later in the day. Models differ with the onset timing of
precipitation and slight variations of the location of the surface
low will affect the amount of precipitation that could result
with the next system. Unsettled weather will continue for Thursday
as the low in the Bering Sea moves into the Gulf. Confidence
remains lower as there are differences with the orientation of the
passing trough and how far south the low sinks into Gulf.

&&

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

Southwest Alaska is seeing a break in more active weather as a
ridge in the Bering continues to move eastward. Some lingering gap
winds are along the Eastern Aleutians and the Alaska Peninsula
due to continued passage of an upper trough. Also, a small weak
low is currently just north of the Alaska Peninsula. This weak low
is allowing for some light rainfall near Cold Bay. The southwest
Mainland is seeing mostly clear skies with some areas of fog
forming. Temperatures in the mainland once again will drop to the
early 20s this (Monday) morning.

Come Tuesday, the ridge will progress eastward over the southwest
mainland and a large low will move from the Sea of Okhotsk toward
Alaska. A front from the low will push into St. Lawrence Island
and the Pribilof Islands Tuesday morning. This front will reach
the Kuskokwim Delta by Tuesday afternoon. Due to the orientation
of the winds (south-southwesterly) and duration of the event (~12
hrs), communities along the Kuskokwim Delta coast will see water
levels rise Tuesday into Wednesday. Coastal flooding is not
expected to be significant, but there is still enough uncertainty
that this outcome is not guaranteed. Westerly to southwesterly
breezy winds will continue through Wednesday after the main event,
so flooding potential remains elevated. The front will push inland
by Tuesday afternoon, driving up precipitation changes in the
Mainland.

Wednesday has the upper trough swing southeastward over the
Mainland, allowing for continued precipitation chances. Northerly
flow from the trough will allow for cold air advection and thus,
colder temperatures over the Bering and southwest Mainland. This
will continue into Thursday as the cold tongue remains over the
mainland. Temperatures are not expected to be as cold as the prior
event. A large ridge moves into the Bering on Thursday, allowing
for lower precipitation chances. Southwest winds will allow for
warmer air to move over the Aleutians.

-JAR

&&

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

Thursday starts out with a Chukotsk low broadening out into a
trough of low pressure over northern and central Alaska by Friday,
with multiple weak embedded lows. Additionally, a strong system
approaches the western Aleutians, evolving into a dominate Bering
Sea storm. This system intensifies by Saturday, sprawling across
the Bering and moves towards Nunivak Island by Sunday. A separate
low near the Kenai and Alaska Peninsula Thursday weakens into a
broad trough by Saturday before being absorbed into the bering
storm's wind field by Sunday and fully merges with it by Sunday
and pushes a frontal system into the western Gulf of Alaska by
monday afternoon.

The major models predict the Bering Sea system over the weekend.
The European and Canadian models are somewhat similar trough day
8, with the CMC slightly stronger and faster. The GFS, however, is
quite different with its earlier forecast period significantly
different than its counterparts but improves towards the end of
the forecast period but still is not in full agreement with the
other 2. The European is currently favored as it leads the trend
of the system moving south and east, ending up weaker and closer
to the Yukon Delta towards the end of the period.

-DD

&&
.AVIATION...

PANC...VFR conditions and light, mainly northerly, winds will
persist.

&&