797
FXAK68 PAFC 160033
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
433 PM AKDT Sat Aug 15 2026

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

The first of several shortwaves works its way north up Cook Inlet
this evening and overnight, bringing with it widespread rainfall
across Kodiak Island, the Kenai Peninsula and Anchorage and then
inland into the MatSu Valley. Additionally, Prince William Sound
will see persistent rainfall through the end of the weekend and
into Monday. High pressure situated along the coast and Copper
River Basin will shift eastward towards Canada as the shortwaves
move through. This will produce a tighter pressure gradient
extending along the eastern Kenai Peninsula and eastern Turnagain
Arm Area. As a result, an uptick in winds is expected starting
tomorrow morning, with southeasterly winds becoming increasingly
gusty through the late morning and afternoon. Strongest winds are
expected tomorrow afternoon and evening. Areas along the Hillside
may see wind gusts up to 60-68mph Sunday evening. Gusty winds are
also expected for Palmer, with gusts to 40 mph possible Sunday
afternoon/evening. Rain may cut off as winds pick up, but is
expected to continue once winds subside.

On Monday, the upper level flow will turn more southwesterly due
to the main upper level low pushing into Southwest Alaska. This
will bring more rainfall especially to the Susitna and Matanuska
Valleys and probably Anchorage and the northern Kenai Peninsula
as well. The gusty gap winds will likely persist through Monday as
this pattern is favorable for Turnagain Arm, Knik River Valley an
along the Copper River.

KM

&&


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


An upper-level low lifts northward across the Alaska Peninsula
(AKPen) this afternoon. Rain sweeps north across the AKPen, as
the first of several shortwaves rotating around the low brings
widespread precipitation to the Southwest Mainland from Saturday
afternoon through Monday afternoon. This system will also bring
small craft advisory winds and areas of gales to Bristol bay from
tonight to Sunday morning. Winds subside briefly Sunday morning
before a second wave of wind moves through Sunday night into
Monday.

By Sunday night the upper low moves over the Southwest mainland
as rain showers continue sweeping around the circulation. Cooler
temperatures will accompany the system, marking a return to a more
typical cool and wet August pattern.

Across the Aleutian Island chain, unsettled conditions will
continue as a weak upper level low sweeps eastward across the
southern Bering on Monday. Rain and gusty winds spread eastward
behind the system, reaching the AKPen by Tuesday afternoon.

&&


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

By Wednesday morning, broad troughing is anticipated across
mainland Alaska with an upper level low sitting at the base of the
trough over the AKPen. This low looks to move across the Gulf
Wednesday and into the Alaska Panhandle on Thursday. There is
general agreement at least a weak surface low will develop in the
southwestern Gulf by Wednesday morning ahead of the upper low and
move into the northern Gulf Coast around Prince William Sound
Wednesday night into Thursday. This will bring more precipitation
(possibly heavy) for the northern Gulf Coast and eastern Kodiak
Island. Depending on the strength of the coastal ridge, offshore
winds in the Gulf and southeasterly gap winds in Southcentral
(Turnagain, Knik, Copper River) may also increase on Wednesday.
Some light precipitation may spill over into interior locations of
Southcentral and Southwest, with highest chances around higher
terrain. Otherwise, mostly overcast skies and cooler temperatures
persist on Wednesday. By Thursday morning, after the low reaches
shore, winds should weaken and precipitation should become
lighter.

Behind the low, troughing persists as shortwaves continue to move
through Southwest and the northern AKPen into Southcentral and
the Gulf. Though details are still uncertain, this general pattern
looks to maintain cooler temperatures and mostly cloudy skies
with occasional rain through the end of the week. Depending on
wave positioning, rainfall is possible across the Bering and
Aleutians into the AKPen and Kodiak Island as well. One other
detail that will be watched is how models continue to resolve a
potential stronger low from Siberia moving into the Seward
Peninsula next Friday-Saturday, which could bring another round
of heavier rainfall for Southwest and stronger winds across the
Bering. Details will become more clear in the coming days.

-PA

&&


.AVIATION...

PANC...VFR conditions will persist through the period, though
ceilings may lower to under 5000 ft starting this afternoon with
an approaching frontal system. This system will bring rain to the
area overnight, though there is a question as to how much will
make it to the terminal in the cross-barrier flow over the Chugach
Mountains. The best chance for rain and a MVFR ceiling will be
late tonight into early Sunday morning. LLWS will also become more
of a concern as cross-barrier flow increases and winds near the
terminal remain light Sunday morning.

Winds should remain southerly to westerly today into tonight but
remain at or under 10 kt through Sunday morning. A stronger
Turnagain wind will come in towards the end of the TAF period.

&&


$$