129
FXAK68 PAFC 171306
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
506 AM AKDT Thu Jul 17 2025

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

A negatively-tilted upper level trough now extends from an upper
level low moving over Southwest out to the northern Gulf. This
feature is losing amplitude and is not having too much of an
impact on sensible conditions at the surface, with little more
than a few very light showers now drifting across the northern
Gulf. Elsewhere, conditions are mostly dry with a patchwork of
scattered to broken cloud cover at varying altitudes drifting in
place as steering flow at both the surface and aloft become more
disorganized with time.

For today, a transient area of high pressure connected to a
blocking ridge now focused to the north near the Interior and
AlCan will briefly attempt to build back into place. This should
yield a relatively sunnier and seasonably warm day as low to mid
level clouds erode, particularly from parts of the Kenai Peninsula
north to the Mat-Su Valleys.

By tonight into Friday, a pair of shortwave troughs associated
with a complex Bering low developing out west will move up the
Alaska Peninsula past Kodiak Island, then up into the northern
Gulf and the remainder of Southcentral. Near the surface, a weak
low will develop along a stalling front as it enters the
southwestern Gulf by Friday evening. Another round of rainfall
ahead of the trough and stalling low/front in the Gulf is expected
to move up from Kodiak Island into the Kenai Peninsula during the
day on Friday, but the inland extent of precipitation continues
to be a point of high forecast uncertainty. Models remain highly
divergent in terms of how much moisture is able to work north
ahead of the trough, with some solutions projecting light rain
reaching as far as the Mat-Su Valleys and Talkeetnas, while others
show little to no rainfall reaching even Seward and Kenai. Still,
any rainfall that does make it into interior Southcentral will
likely stay on the lighter side, and it still looks very likely
for the Copper Basin to stay mostly dry and warm through the start
of the upcoming weekend.

By Saturday, the shortwave trough will lift northeast towards
the Yukon as a rapidly building North Pacific ridge expands north
into much of the region in its place. This will kick start another
seasonably warm and dry stretch that could last into early next
week.

-AS

&&


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

A longwave pattern remains well established over the Bering with
an upper low anchored roughly 380 nautical miles north of Shemya.
Broad cyclonic flow around the low and the Bering will push two or
more systems through the Aleutians through the end of the week.
On satellite, the first of these systems is a wave of low pressure
currently tracking along the Aleutian Chain near Unalaska. This
wave will slide into Southwest Alaska with an attendant front
through Friday with another round of widespread showers expected
tonight into tomorrow morning. Gusty southeasterly winds will
accompany the front`s progress over the course of today with the
usual gap wind locations to see wind gusts as high as 35 knots or
greater, especially for Cold Bay through the around midday. The
front is forecast to reach the northern half of the Alaska
Peninsula and Bristol Bay by late afternoon. Small craft
southeasterly winds will impact Port Heiden and Pilot Point, as
well as much of Bristol Bay before midnight tonight.

Little change in the Bering low`s position will see the next
front push into the Central Aleutians during the morning hours on
Friday, with an axis of small craft winds moving from Adak and
Atka during the morning hours, to Unalaska and Dutch Harbor by
Friday afternoon. It will be a cool and showery end to the
workweek with precipitation over much of the Bering today,
followed by more precipitation Friday into Saturday morning. With
the shower activity expect continued low stratus to blanket the
region along with areas of fog at times.

More uncertainty exists with the forecast on Saturday. Low
pressure should remain firmly in place over the Bering. A stalled
front, stretching from the Alaska Peninsula, southwestward, into
the North Pacific may see training showers over the AKPEN
communities followed by potentially heavier showers on Sunday.

-BL

&&

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

Sunday morning the pattern will be lead primarily by a mature
upper-level low pressure system in the Bering Sea, with a ridge of
high pressure building in the Gulf of Alaska. A front will be
situated across the eastern Aleutians/southern Alaska Peninsula and
Bering Sea, spinning off into an independent weak low pressure
system near Kodiak Island by late Sunday morning. Through the
late weekend into the early work week, an unsettled pattern may
persist for the Southcentral and Southwest regions of mainland
Alaska, with weak features spinning in from the anchored low in
the western Bering. The strength of the subsequent low pressure
systems that form off in the Gulf of Alaska initially appear
fairly weak, given the proximity to the strong ridge in the
northern Pacific.

-CL

&&


.AVIATION...

PANC...VFR conditions will persist, with light southerly winds
this morning becoming westerly this afternoon as the sea breeze
develops.

&&


$$