167
FXAK68 PAFC 181245
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
445 AM AKDT Tue Aug 18 2026

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

A complex longwave trough continues to drift over much of the
greater Alaska region this morning, with several embedded smaller
troughs slowly moving northeast along an axis between the
Aleutians and the Yukon. The leading trough in this series is the
one responsible for the blustery and wet conditions across
parts of Southcentral yesterday, now exiting across the AlCan
border into the Yukon. Gap winds are beginning to trend down as
the north-south pressure gradient slowly relaxes, and this
weakening trend should continue today into tonight. The next
shortwave disturbance to watch is now starting to lift from
Southwest into the western Alaska Range, and this feature will
likely become a key player in today`s outlook across Anchorage
and the Mat-Su Valleys. It`s looking like this trough will stay a
bit more intact as it crosses over into northern portions of
Southcentral today, increasing the threat for shower redevelopment
over both higher terrain and lower elevations this afternoon.

By late this evening, the shortwave poised to move into the Mat-Su
Valleys will shift into the Copper Basin.  Lingering shower
activity will trend in the same direction, while the rest of
Southcentral temporarily dries out in between systems from tonight
into Wednesday morning. By the late morning to mid afternoon on
Wednesday, a weakening low moving along the AKPen will send its
occluded front into Southcentral. This will send renewed bands of
light rain quickly northeast, first reaching Kodiak Island and the
Kenai Peninsula, then shifting into the Mat-Su and Prince William
Sound later in the day. Models are struggling a bit to pin down
the location for the development of a new surface low at the
frontal triple point, but it looks most likely (around 70%
chance) to form close to Kodiak Island and the Barrens by
Wednesday night. As this new low forms, the front will sharpen
somewhat as it nears the Gulf Coast, with a weak barrier jet
likely to form along it as it approaches the northern Gulf
coastline late Wednesday night into early Thursday. Easterly winds
will peak at or near Small Craft range along the front early
Thursday morning, namely south of the Kenai Peninsula and Prince
William Sound.

Looking closer to the end of the week, the main low moving up from
the Aleutians and AKPen will shift northeast into Southcentral
through Thursday evening. Expect this to extend the cool, showery
and cloudy pattern for much of the region through at least
Thursday night.

-AS

&&


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

The active pattern continues across Southwest Alaska, the Bering
Sea and Aleutians through the middle of the week as a series of
upper-level lows track across the region. Showers lingering across
Bristol Bay early this morning will continue to push off to the
north and east into the Kuskokwim Valley and along the western
Alaska Range throughout the day today as the first upper level
feature exits the region. Elsewhere across Southwest, low stratus,
patchy fog, and misty conditions continue through this morning
into this afternoon as the next system quickly follows by
Wednesday morning.

Farther west, the low currently centered over Nikolski continues
to track along the Aleutian Chain and Alaska Peninsula through
Wednesday before eventually pivoting south into the Gulf by
Thursday morning. Light rain associated with this system continues
across the eastern Aleutians and AKPen through tonight before
overspreading Southwest Alaska by Wednesday morning.

Looking ahead to the end of the forecast period, a strengthening
low entering the western Bering for Thursday into Friday will
bring the next round of widespread gusty winds and rainfall across
the Bering and Southwest Alaska.

&&


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

The long term begins with a strong zonal jet between Kamchatka
and western Alaska that will amplify into a broad trough over the
state on Saturday and Sunday. The jet streak over the Bering will
help to generate a fairly strong and broad low pressure system
that will impact southwest Alaska starting early Friday. Depending
on the track and timing of this system, which has a fairly large
spread, there are concerns regarding the potential for coastal
flooding, high surf, and/or erosion. It`s difficult to pinpoint
where this may occur at this time with guidance highlighting a
broad area of concern from the northern Alaska Peninsula all the
way to the Y-K Delta.

The other aspect to this system is significant rainfall. Although
there isn`t a deep connection to the pacific and tropical
moisture, a decent slug of warm, moist air will accompany the
system. Models are indicating 1-2 inches of rain may fall on
Southwest Friday and Saturday. The storm will pass into
Southcentral and then the Gulf over the weekend, with a widespread
1-3 inches of rain possible. Given the wet environment,
particularly in the Susitna where flooding is currently occurring,
flood concerns will rise once again. Winds look strong through
the Bering, Southwest, and Gulf of Alaska/Kodiak Island.

&&


.AVIATION...

PANC...VFR conditions are expected to remain through the TAF
period, though periods of showers may cause ceilings to dip to
as low as MVFR range at times. Gusty southerly to southeasterly
winds will persist through the day, though will gradually diminish
this afternoon into tonight.

&&


$$