700
FXAK68 PAFC 180014
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
414 PM AKDT Fri Jul 17 2026

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

Radar imagery this afternoon shows showers continuing to stream
north across Prince William Sound and the Kenai Peninsula, with
the heaviest band of showers tracking from Turnagain Arm into the
Susitna Valley. Showers should continue to become more scattered
through this evening as the trough axis lifts north, although
lingering moisture and weak instability will promote rain chances
to persist through much of Saturday ahead of the next system.

Active weather continues through the weekend into next week as
the pattern becomes more amplified Saturday. A strong upper level
low slowly tracking east in the southeastern Bering coupled with a
strengthening ridge across western Canada will help to direct an
atmospheric river into the western half of Southcentral through
the weekend. The heaviest precipitation is expected to begin by
late Saturday afternoon into Saturday evening across Kodiak Island
and the southern Kenai Peninsula before working its way north
across the Kenai Peninsula, western Prince William Sound, and the
Susitna Valley Saturday night. Heavy rain will persist for these
areas through Sunday. Anchorage and the Mat Valley are likely to
see another brief period of rain Saturday night along the leading
edge of this storm before stronger cross- barrier flow develops
leading to downsloping and relatively drier conditions.

By Monday morning, the upper level trough extending into the Gulf
becomes more negatively tilted as precipitation fills back in
across Anchorage and the Mat Valley as flow aloft weakens.
Generally expect rainfall to taper off from southwest to northeast
through Monday as the axis of moisture finally begins to progress
eastward.

&&

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

The forecast, albeit active, still looks to be on track. Radar
returns this afternoon show rain trying to fill in from west to
east across Bristol Bay and the Alaska Peninsula, with more
showery weather across the Southwest Interior. There have been
more convective showers firing this afternoon across the central
Yukon-Kuskokwim Delta where a few rumbles of thunder cannot be
ruled out this evening, though instability is quite limited.

Once again, another cycle of relatively "warm" overnight lows in
the mid to upper 40s is in store for Southwest Alaska and the
Alaska Peninsula due to rainfall and cloud cover. The large,
amplified upper level trough remains anchored over western Alaska
and the eastern Bering Sea. At the surface, a gale force low is
moving across the Pribilof Islands, while its front brings gales
to the Pacific side of the Central and Eastern Aleutians. This low
is near occlusion or is in the process of occluding as it becomes
more vertically stacked, which will cause the cyclone to fill as
it continues to move southeastward towards the Alaska Peninsula
through tonight. As cold air continues to work in behind the
system, a corridor of northerly to northwesterly high end small
craft to gale force winds have developed to the west and southwest
of the Pribilof Islands this afternoon, which are on track to
last into Saturday.

The Bering low, now in the southeast Bering by Saturday morning,
slows its progression and remains in the southeast Bering through
early Sunday morning before it lifts towards Kuskokwim Bay late
Sunday morning. With little progression and numerous shortwaves
rotating around the upper-level low portion of the system, most of
Southwest continues to see rain through Saturday and Sunday. In
addition to the rain across Southwest for Saturday, expect gusty
easterly to southeasterly winds to pick up through Kamishak Gap
and into Interior Bristol Bay and Iliamna as the pressure gradient
tightens. The gustiest winds, around 35 to 40 mph will be felt
across Iliamna Saturday evening with gusts up to 25 to 30 mph
across Koliganek and New Stuyahok. These winds will slowly
diminish through Sunday as the pressure gradient weakens. However,
southeast winds out of Kamishak Gap will remain through Sunday
with the low in Kuskokwim Bay. As the low moves towards Kuskokwim
Bay Sunday, it will be in its weakening phase with small-craft
southerly to southeasterlies left over across Bristol Bay. Rain
continues into Monday as the main 500 mb trough remains draped
across Southwest and shortwaves move across the area from the
Bering and North Pacific.

Aside from the rain that the Bering low`s front brings the
Aleutian Chain today, Adak/Atka dry out for Saturday as a
shortwave ridge builds in. Nikolski/Unalaska/Akutan still contend
with showers at times Saturday with northerly flow off of the
Bering and shortwaves moving over the area from the north on the
backside of the low. Meanwhile, showers across Shemya taper off
this afternoon as the ridge builds in. Any break in rain will be
short lived as a series of shortwaves move over the area from
Kamchatka starting tonight through Sunday. Another shortwave ridge
develops across the Western Aleutians for Monday. Stay tuned for
forecast updates as the active pattern across the Bering,
Aleutians, and Southwestern Mainland continues to unfold.


&&


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

Forecast models continue to favor a longwave trough over the
Bering, which keeps both Southwest Alaska and Southcentral Alaska
within southwesterly flow for the foreseeable future. This will
promote numerous opportunities for additional rainfall as each new
low pressure system or trough lifts through the interior. As
such, expect below normal temperatures to continue and above
normal precipitation chances through the end of next week.

-BL

&&


.AVIATION...

PANC...Widespread rain showers will continue to move across
west Anchorage, including ANC, today in response to an upper-level
trough lifting through the region. Some duration of break in
precipitation is expected this evening/overnight before returning
tomorrow morning with the next wave rotating northward. Winds will
generally be on the light side, under 10 kts, through the first
half of the period before gusty SE winds out of the Turnagain Arm
pick up on Saturday afternoon. Flight CATs from CIGs and VIS
likely to remain VFR though much of the period, but can`t rule out
short periods of MVFR during bouts of heavier rain.

-Brown

&&



$$