600
FXAK68 PAFC 270016
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
416 PM AKDT Sat Sep 26 2026

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

Unsettled weather will persist across Southcentral AK through early
next week, with more organized precipitation tonight giving way to
isolated to scattered showers and gradually cooler temperatures.
Precipitation along a trough is currently spreading northward
across the Gulf and into the Kenai Peninsula and Cook Inlet
region. The trough ties back to an upper-level low currently
positioned across the far eastern Bering near Bristol Bay. The
trough will rotate north through the evening and overnight hours,
bringing precipitation to much of Southcentral AK. Kenai,
Anchorage, and areas farther inland of the coastal mountains will
experience some rain shadowing, limiting precipitation, with the
most intense rainfall focused across the mountains. The best
chance for measurable rainfall will occur as the front and upper-
level shortwave trough lift through tonight.

By tomorrow (Sunday), the low will transition east from Bristol Bay
across the AK Peninsula and toward Kodiak Island. This places much
of the Gulf of Alaska in broad cyclonic southerly flow, favoring
widespread rain shower activity across the Gulf, with showers moving
north into the coastal Kenai and Chugach Mountains. Showers will
likely spill across the mountains into the Kenai Peninsula,
Anchorage, and Mat-Su, though coverage will generally be isolated to
scattered.

The low will continue eastward across the Gulf on Monday,
maintaining modest outflow gap winds through favored gaps, including
Shelikof Gap and the Barren Islands where it may be most pronounced.
With the low positioned in the Gulf, most precipitation will remain
focused across those waters, though isolated showers will affect
inland areas as weak shortwave troughs aloft rotate around the low,
coincident with residual moisture and limited mid-level instability.

Sensible weather on Tuesday is likely to be quite similar to Monday
as the synoptic pattern begins to transition. Models begin to
diverge considerably on Tuesday as they struggle to handle the depth
of a shortwave trough digging across western/central AK and its
interaction with the remaining Gulf low. Despite the increasing
synoptic uncertainty, sensible weather remains fairly similar across
most scenarios, with another day of isolated to scattered showers
across much of Southcentral AK.

Temperatures during this period will generally feature highs in the
lower 50s and lows in the upper 30s to lower 40s across most
populated lower-elevation areas. Typically cooler spots (Copper
River Basin, Susitna Valley, etc) will run a few degrees colder. A
gradual stepdown in temperatures is expected through the week, with
nights near or below freezing becoming increasingly common away from
the immediate coastline.

-Brown

&&


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

Key Messages:

* Showers continue across Southwest Alaska through Monday.

* Small-craft force winds persist across the eastern Bering and
  AKPen through Tuesday morning.

Discussion:

A vertically stacked low over the eastern Bering Sea remains the
dominant feature across the region. The upper-level circulation is
readily apparent in the 500 mb pattern, with several lobes of
enhanced vorticity rotating around the broader circulation. At the
surface, the low remains quite deep, while the associated front
has pushed inland into the Interior. While the pressure gradient
surrounding the low remains sufficient for strong winds across
portions of the Bering Sea, Aleutian Chain, and the Alaska
Peninsula (AKPen) the overall trend will be toward diminishing
winds as the system slowly loses organization.

The vertically stacked low slowly moves east throughout the
forecast period, crossing the AKPen Sunday evening and moving into
the western Gulf on Monday. During this time, the upper low
becomes more elongated and the system continues to lose
organization. Shortwaves will continue to rotate around though.
With cyclonic flow aloft and lingering low-level moisture,
showers will continue across Southwest Alaska and the AKPen
through Monday, especially when shortwaves rotate through. Shower
activity will be highest through Sunday evening, then becomes
more isolated on Monday as upper level support continues to move
farther east, with the Kilbuck Mountains and the AKPen seeing the
highest chances for precipitation. The heaviest and most
persistent rain will be in the AKPen, especially where winds
upslope the most along the mountains.

Westerly small-craft to gale-force winds in the eastern Aleutians, the
AKPen and surrounding waters slowly weaken overnight tonight. As
the low continues east, winds slowly turn from westerly to
northwesterly Sunday. Cold air advection on the west side of the
low will allow small- craft force winds to persist in the eastern
Bering and through gaps in the AKPen through Tuesday morning. For
the AKPen, this will contribute to more persistent rain compared
to Southwest.

Cold air advection behind the low will also steepen mid- level
lapse rates across the region. With some instability and enough
upper- level support, a lightning strike or two cannot be ruled
out around Bristol Bay through Sunday evening. There is roughly a
20 percent chance for this to happen. Additionally, incoming cold
air will allow overnight lows to dip to the low 30s by Monday
night for Southwest and the mid to upper 30s for the AKPen.

For the western Bering and western Aleutians, winds continue to
diminish tonight. With no significant upper level features or
lows moving in, the weather will be benign there for the next few
days.

- PA


&&


.LONG TERM FORECAST (Days 4 through 7: Wednesday through
Saturday)...

The middle of the week begins with a complex upper level trough
over the southern mainland and Gulf of Alaska and a surface low in
the northeast portion of the northeastern Gulf. Gusty northwest
gap and pass winds should persist along the Southcentral coast,
especially near Kodiak Island and the Barren Islands.Farther west,
cool northwesterly flow from the Bering Strait down the western
coast will keep Southwest Alaska in the 30s to 40s through the end
of the week. A low-amplitude ridge moving across the central
Bering and Aleutian Islands should keep conditions relatively
quiet at first, but a Kamchatka low is expected to reach the
central and western Bering and Aleutians by Wednesday afternoon.
That system and its leading front will then push east, bringing
gusty southeasterly winds and moderate rain.

By the end of the week, Guidance splits on the Bering low. The
European model is the largest outlier, holding the Bering ridge
much farther west through Friday and Saturday while digging
another trough south from northern Kamchatka into the Alaskan
Peninsula and Gulf between Wednesday and Friday. That trough would
deepen into a southern Gulf low on Saturday after interacting
with another Pacific system. Most other models keep the original
Bering low and its upper level trough as the dominate feature,
tracking the surface east along the Aleutian Chain through
Saturday. If that solution happens, gusty south to southeast winds
and frontal rain would shift from the Bering and Southwest into
Southcentral Alaska Friday into Saturday, with the heaviest rain
focused along the Northern to Northeast Gulf coast and interior
Southcentral remaining drier in the latter half of the week.

-DD


&&


.AVIATION...

PANC...VFR conditions will persist through the TAF period. Similar
to yesterday, continued southeasterly winds aloft will keep a
threat in play for LLWS until winds begin to relax behind a
weakening frontal passage late tonight. Southeast winds could
briefly affect the terminal at the surface for a few hours this
afternoon and evening, but winds will otherwise stay mainly light
and northerly through tonight. A period of light rain and lower
(but still VFR) ceilings is likely late this evening into early
Sunday morning, tapering off to widely scattered showers for the
rest of the morning on Sunday.

-AS

&&

$$