800
FXAK68 PAFC 142331
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
331 PM AKDT Fri Aug 14 2026

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

Ridging remains over Southcentral Alaska today, leading to warm
temperatures into the mid 70s over inland areas, light winds, and
mostly sunny skies to prevail. There is sufficient moisture for
low chances (~10%) for isolated thunderstorms over the Susitna
Valley this afternoon, but the lack of lift due to the ridging
will make it difficult for storms to form. Most thunderstorms, if
they form, will be relegated to the mountain ranges and the
slopes.

The ridge will be forced eastward on Saturday due to troughing
pushing in from the west. Compared to yesterday, this is moving in
faster and will prevent a shortwave from the interior from
dropping down as much as previously thought. This means that
chances for thunderstorms over the Copper River Basin are markedly
decreased from yesterday for both their extent and number. Most
thunderstorms will develop over higher elevations of the Alaska
Range and the Talkeetna Mountains. The Susitna Valley could also
see a few isolated thunderstorms before the next front moves in.

Saturday night into Sunday, a pattern shift will take place as a
strong low moves over Bristol Bay, driving a front into
Southcentral. The front will bring rainfall into Kodiak Island and
Coastal Southcentral Saturday night with the rain spreading into
more protected areas such as Anchorage and the Susitna Valley on
Sunday. The Copper River Basin, however, will remain drier at this
point. This front will also increase the gap winds on Sunday for
the usual suspects: Turnagain Arm, the Knik River Valley and along
the Copper River. By Monday, rainfall and gusty winds will begin
tapering off, but southwest flow will allow for continued chances
for rainfall for the Kenai Peninsula, Anchorage, and the Mat-Su.

-JAR/EZ

&&

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

The Southwestern Mainland experienced another warm and muggy day
today with temperatures in the 60s and 70s and dew points in the
upper 50s and 60s. Showers and thunderstorms will continue the
rest of today and into tonight as a series of upper-level
vorticity maxima lift over the area from the North Pacific and
eastern Bering. The atmosphere is a little more stable near King
Salmon and Dillingham with showers moving over the area this
afternoon. This showery activity will taper off through tonight.

The main upper-level disturbance, which is currently over the
Alaska Peninsula (AKPEN), will move to Dillingham and Bristol Bay
by early Saturday morning. This progression is a little faster
than yesterday`s forecast. The result of the faster northward
progression of this system is that the atmosphere will be a little
more stable Saturday afternoon and evening contrary to the rest
of today and tonight. Thus, there will be less storm coverage and
less lightning activity. However, isolated thunderstorms are still
likely along the Kuskokwim Delta, Kuskokwim Valley, Interior
Bristol Bay, and along the Western Alaska Range.

The upper-level shortwave responsible for Saturday`s showers and
isolated thunderstorms will move off to the north across the Yukon
Delta by Saturday evening. This will mark the beginning of a
pattern change to more of what August is about; cool and wet.
Middle to upper-level flow turns southwesterly Saturday night
through Sunday morning as a low in the North Pacific moves into
the eastern Bering by late Sunday morning.

Numerous shortwaves associated with this system will lift from
the North Pacific and eastern Bering will move across the AKPEN
starting Saturday afternoon and across the Southwestern Mainland
starting Saturday night to early Sunday morning. The result will
be steady rainfall across those areas. Rain will pick up in
intensity across Southwest and become moderate to heavy at times
by Sunday afternoon and evening as the surface low moves to the
vicinity of Kuskokwim Bay. Steady rain continues across Southwest
for Monday as the low moves to around Norton Sound by Monday
afternoon to evening.

Meanwhile, steady rain becomes more showery across the AKPEN by
Sunday night as the main synoptic forcing moves to Southwest.
After a bout of rain for Adak/Atka and Nikolski/Unalaska/Akutan
Saturday and into Sunday, a drying trend begins Sunday afternoon
across the Central Aleutians and extends to the Eastern Aleutians
by Sunday evening and night. Another weak system dropping down
from Kamchatka may deliver another round of showers to Adak/Atka
Monday. Rain is expected to be light with this system. Shortwaves
rotating on the backside of the low responsible for all the rain
across Southwest Saturday night through Monday will also bring
rain to the Pribilof Islands by Monday afternoon and evening. Stay
tuned to forecast updates we transition from a thunderstorm
pattern across Southwest to the more classical August pattern of
cooler and wet.

&&


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

By Tuesday morning, there is general agreement of a vertically
stacked low being over the Lower Yukon Valley. Troughing extends
down through the Aleutians, with the most significant shortwave
outside of the low being over the western Aleutian Chain. Models
hint at shortwaves continuing to rotate around the low as it
continues northward into the Interior. This will maintain chances
for precipitation for much of the southern Mainland Tuesday.
Specific timing of these waves is unknown, but the heaviest
precipitation is expected to fall along coastal regions of the
Northern Gulf Coast/Prince William Sound and along the Alaska
Range in the western Susitna Valley. Out west, the Aleutians and
Bering likely see showers Tuesday as the shortwave moves east.
The shortwave over the western Aleutians becomes a closed low over
the eastern Aleutians by Tuesday evening. This looks to pull
additional moisture in and bring another round of rain for the
eastern Aleutians, Southern AKPen, and Kodiak Island Tuesday night
through Wednesday. This low crosses the southern AKPen into the
Gulf Wednesday morning and moves into the Alaska Panhandle on
Thursday. As the low moves through the Gulf on Wednesday,
rainfall will likely shift to the northern Gulf Coast east of
Prince William Sound with some spilling over into interior
locations of Southcentral. Models diverge with resolving certain
surface features (mainly whether or not a surface low develops in
the Gulf on Wednesday). If a surface low develops in the Gulf
Wednesday, rainfall may be enhanced along the northern Gulf coast.
Some southeast gap winds (Turnagain, Knik, and Copper River
winds) may be enhanced as well on Wednesday. These details will
become more clear in the coming days.

To the west of the lows, models diverge on solutions between
zonal flow and attempts at a ridge building in the Bering with
additional shortwaves traversing into the southern Mainland.
Either pattern would support cooler temperatures and mostly overcast
skies across much of southern Alaska and the Bering with
continued chances for precipitation across the southern Mainland.

-PA

&&


.AVIATION...

PANC...VFR conditions and light winds will persist through much of
the period. By Saturday morning, a frontal system pushes into the
area which will increase cloud coverage and lower ceilings.

&&


$$