Mill Bay, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

152
FXAK68 PAFC 200039
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
439 PM AKDT Wed Aug 19 2026

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

Generally speaking, the forecast expectations through the end of
the week are little changed, with an overall cool and showery
pattern expected to continue. Currently, low pressure resides over
the southern AKPen with a shortwave ridge over the Copper River
Basin. The Copper Basin has been relatively clear today underneath
the ridge, whereas overcast conditions are seen across the rest
of Southcentral. The low currently moving near the AKPen and
Bristol Bay will crawl slowly east past Kodiak Island and cross
the Gulf of Alaska over the next few days, and this will be the
main focal mechanism for the continued wet and cloudy conditions.
An initial frontal wave moving ahead of the occluded low passed
over Kodiak Island this morning and continues northeast into the
Kenai Peninsula, Mat-Su, and Prince William Sound through this
evening. Bands of showers will continue along and behind the front
as it moves from southwest to northeast throughout the evening.
Places currently dry in the Kenai, Mat-Su, and Prince William
Sound will see the onset of showers by early evening. For the
Copper River Basin, frontal progression will push the ridge out by
this evening and bring in more cloud cover. This will also push
out any haze still lingering in the area.

By early tomorrow morning, a weak low will attempt to form along
the surface front`s triple point in the Gulf somewhere in the
vicinity of the Barren Islands. A period of Small Craft winds
still looks on track to develop along the front south of Prince
William Sound and the Kenai Peninsula on Thursday before the front
reaches the coast and shears apart by Thursday evening. Farther
north, showery conditions will continue for much of interior
Southcentral through Friday as weak southerly flow ahead of the
weak Gulf low continues to transport moisture into the region.
Steadier rain will persist along the coast near Prince William
Sound until the low finally begins to shift to the east into the
northern Alaska Panhandle and Yukon Territory by late Friday
evening.

The next system moves into Southwest Alaska late on Friday and
sends a front into Southcentral and the Gulf. With southerly upper
level flow being maintained, mostly cloudy skies, seasonal
temperatures, and additional chances for rain are likely for
Southcentral starting Friday night and lasting through Saturday.
The highest chances for steady rain Friday night through Saturday
will be along the western Alaska Range and along the northern
Gulf Coast, especially around and east of Prince William Sound.

- PA/AS

&&


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

Satellite imagery this afternoon reveals low stratus across the
Southwestern Mainland, the Pribilof Islands, the Bering Sea, the
Alaska Peninsula (AKPEN), and the Aleutian Chain. More plainly,
there is low stratus everywhere this afternoon. A weak low
pressure system currently just north of the southern AKPEN
continues to slowly move east towards the waters of Bristol Bay.
The system moves into Bristol Bay by Thursday morning and then
transfers its energy to the western Gulf of Alaska through
Thursday afternoon. Off and on showers will continue across
Southwest through Thursday.

A stronger and wetter system develops in the northern Bering by
Friday. The main upper-level trough digs across Siberia Thursday
afternoon as shortwave energy rides eastward into the Bering from
Kamchatka. The NAM guidance has been aggressive with phasing these
two energies together to produce a stronger surface low Friday.
Meanwhile, other guidance such as the GFS, Canadian, and European
all keep the shortwave energy from Kamchatka moving south of the
main trough and out ahead of it as well. Therefore, there is less
phasing and a resultant weaker system. The weaker solution is what
this forecast package represents. Despite the weaker system, it
will be a wet one. Light to moderate rain will arrive to the
Pribilof Islands early Friday morning. This rain then moves to the
Southwestern Mainland at the Kuskokwim Delta Coast by late Friday
morning and across the rest of Southwest through the rest of the
day. The low continues into Western Alaska as steady rain across
Southwest tapers to showers from west to east.

The low will depart Southwest and head for the Gulf through
Saturday evening. Behind the low, northerly flow will develop
across the eastern Bering as a ridge builds across the central
Bering. The main Siberian trough will dig southward across
Southwest and across the AKPEN Saturday morning through Saturday
evening. This will cause enhanced winds through the gaps of the
Eastern Aleutians and the gaps and passes along the Pacific-side
of the AKPEN. There is not a lot of cold air expected to drop down
from the north as the trough digs, so expect small-craft winds
with some gale-force gusts through the gaps and passes of the
Eastern Aleutians and AKPEN.

Another low pressure system lifts from the North Pacific to the
western Bering and Western Aleutians Saturday morning upstream of
the ridge in the central Bering. This system will bring in a push
of warm and moist tropical to sub-tropical air into the western
Bering through Saturday. Rain moves from Shemya Saturday morning
to Adak by Saturday evening. By Saturday evening, expect sustained
small craft winds across the western Bering. There are
indications that winds will strengthen further as pieces of upper-
level energy interact and potentially phase with one another
towards the second half of the weekend. Stay tuned for forecast
updates as the active weather pattern across Southwest and the
Bering Sea continues to unfold.

&&


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

The long term forecast remains active over Southern Alaska.
Sunday will see a low move into the Bering from Kamchatka, leading
to gusty winds and rainfall over much of the Bering, including
the Pribilof Islands. The Southwest mainland will have ridging
over it and thus, weaker winds and low rain chances. There is a
decent amount of uncertainty regarding intensity of rainfall and
winds with the low. Southcentral will also have a low over the
Gulf of Alaska, but by Sunday afternoon, the low will have moved
out east, with rainfall diminishing over Southcentral.

By Monday, the low in the Bering will take a turn to the north due
to ridging over the mainland. However, the low`s front will still
progress eastward, pushing inland by Monday afternoon as the ridge
moves east. This rainfall will last into Tuesday as a trough moves
in and reinforces the rainfall. In Southcentral, ridging arrives
on Monday, allowing for clearer skies and weaker wind speeds. This
will last until Tuesday evening, when the aforementioned trough
continues eastward and drapes over Southcentral. The trough will
bring rainfall likely across the Susitna Valley and even into
Anchorage and Western Kenai.

Come Wednesday, uncertainty increases with the potential for a low
to move into the Bering. This would bring gusty winds and rainfall
across the Aleutians. Southcentral Alaska may see lingering
rainfall if the trough moves out slower, otherwise, rainfall will
diminish as zonal flow arises. Again, the exact track of features
cannot be realized as of now, so the forecast is likely to change.

-JAR

&&


.AVIATION...

PANC...Predominantly VFR conditions expected through the period
with the potential for some brief drops to MVFR in visibility and
ceilings as scattered showers move across the area tonight.
Showers will begin to wind down between 09-12Z, though VCSH still
possible into the afternoon hours as showers linger along the
higher terrain. Winds will remain light generally switching
between SE and northerly.


&&


$$