919
FXAK68 PAFC 180028
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
428 PM AKDT Sun Aug 17 2025

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA
Days 1 to 3: (Sunday afternoon through Wednesday afternoon)...

Mostly sunny skies and decreasing wind gusts remain in place
through late tomorrow evening as high pressure builds into
Southcentral. A short wave moves through Southcentral pushing the
high pressure into the Gulf of Alaska. Ahead of the shortwave
moving over SOuthcentral, southwesterly winds will bring up-Inlet
flow Monday evening through late Tuesday morning. Gusts as high
as 20 knots are expected during this time. Rain showers arrive in
the Mat-Su Valley overnight, in the Anchorage Bowl Tuesday morning
and the Copper River Basin and Prince William Sound Tuesday
afternoon. Currently, rainfall amounts in these areas range from a
quarter to an inch during the day Tuesday. Cooler temperatures
will accompany the rainfall with highs dropping from the 70s into
the lower 60s.


&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS
Days 1 to 3: (Sunday afternoon through Wednesday afternoon)...

The forecast remains on track, with few changes since the previous
forecast update. Overall forecast confidence is medium to high, with
lowest confidence regarding the extent and severity of fog.

A low in the southern Bering Sea brings light to moderate rain as
it moves across the Aleutian Islands through Monday evening. As
the low exits south towards the North Pacific, northerly gap
winds increase along the Eastern Aleutians and Southern Alaska
Peninsula through Monday. Also on Monday, a front enters the
Western Bering and moves northeastwards across the Bering Sea
through Wednesday afternoon, bringing southwesterly winds to 30 kt
and light rain.

For Southwest Alaska, upper level shortwave troughs will bring
a slight chance of showers to Kuskokwim Delta through Monday.
Then, a stronger trough will bring more widespread rain chances to
the Kuskokwim Valley for Tuesday. By Tuesday afternoon, skies will
begin to clear across Southwest Alaska as transient ridging moves
in. This will lead to cooler nighttime temperatures from Tuesday
night into Wednesday morning, with overnight lows dipping into the
low 40s and perhaps even into the high 30s for Kuskokwim Valley.
Clearer skies will be short-lived, however, as cloud cover begins
to build back in with the approaching Bering Sea front on
Wednesday.

-ER/KC

&&

.LONG TERM FORECAST (Days 4 through 7/Thursday through
Sunday)...

The main weather feature for Southcentral will be a persistent
deep Arctic upper level low-pressure system. Shortwave energy from
this system will begin to sweep across the area, leading to a
period of active precipitation that will continue through the
weekend. High temperatures will remain seasonally average but
widespread cloud coverage will likely keep overnight lows warmer
than normal.

For the Bering Sea and Aleutian Islands, the weather pattern will
undergo a significant change late in the week. A high-pressure
ridge that has been over the Bering Sea will weaken, allowing a
new deep low-pressure system to form. This system is anticipated
to bring a substantial plum of moisture from the Bering Sea into
the western part of the State. By the weekend, this could lead to
heavy rain over portions of the West coast and interior of Alaska.

The European model is favored early on with a transition to the
Ensemble blend towards the end of the forecast period.

-DD

&&

.AVIATION...

PANC...VFR conditions and light winds will persist through Monday
afternoon. Winds will switch to southerly late this evening.
Turnagain Arm winds expected to increase by Monday evening.


&&


$$

386
FXAK67 PAJK 172332
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
332 PM AKDT Sun Aug 17 2025

.SHORT TERM.../tonight through Monday night/...Light rain sticks
around for parts of the panhandle as wind speeds decrease.

Key Messages:
-Easterly wave will keep rain showers over the northern half of the
panhandle.
-Southern half will have diminishing showers with decreasing cloud
cover tonight.
-Wind speeds are expected to decrease as the low in the gulf
weakens and moves away from the panhandle.

Details: General area of low pressure in the gulf will weaken and
slide southward. As it does, the pressure gradient over the
panhandle will lighten up and allow wind speeds to decrease or
remain light/variable tonight with the lighter winds lasting
through Monday night. That being said, Eldred Rock has been
reporting 20 to 30 kt southerly winds today. Wind speeds should
drop below 20 kts later this evening with continued decreasing
winds overnight.

For the rain showers, there are two weather patterns happening over
the area - diurnal pop-up showers in the south and an easterly wave
in the north. The showers in the south will, for the most part,
decrease in number once the sun goes down. Any exceptions to this
will be caused by a rogue shower that drifts in from south of the
panhandle but they wouldn`t last long. Otherwise, skies will be
clearer and an overall quiet night with the quiet weather lasting
into Monday.

For the northern showers, these are coming from an easterly wave
that is bringing the moisture in from Canada. A reinforcing 500mb
vort max will keep high the PoPS in place until around 10AM to Noon
Monday. That`s when the showers look to really decrease with the
drier weather lasting through Tuesday morning. A few showers are
possible mainly along the coast on Tuesday, before those chances
move inland later in the day.

.LONG TERM.../Into next weekend/...Overall drying trend late this
week with warmer temps likely for the later half of the week.

Key Messages:
-Lingering low pressure passing to the south will give some rain and
rain shower chances mid-week. 24 hour rain amounts will be light.

-A building ridge of high pressure afterwards will bring drier
weather and warmer temps for the later part of the week into next
weekend.

-Marine wind speeds look to be on the lighter side next week at
around 5 to 10 knots with some isolated trouble spots getting up
to 15 knots due to afternoon sea breeze enhancement.

Discussion: A passing area of low pressure will keep at least some
rain chances over the panhandle mid-week. Greatest PoPS are in the
south with lower PoPS in the central and northern panhandle. Rain
amounts look to be light due to the spotty nature of the showers.

After the lingering low finally moves on and out of the area mid-
week, a potential ridge of high pressure looks to move in. This
would bring decreasing rain chances and decreasing cloud cover. So
sunnier skies are looking likely later next week. With sunnier skies
comes warmer temps, with highs warming to the upper 60s to the near
70 for Thursday into next weekend.

&&

.AVIATION...The northern panhandle will continue to see light to
moderate rain through Sunday night before more breaks breaks
between showers show up late Sunday night into Monday. The primary
circulation in the gulf continues to slide westward, with surface
winds across the inner channels gradually falling as a result.
Last holdouts through the afternoon hours will be the far northern
inner channels. Still no LLWS concerns for the TAF period going
forward. Far northern inner channels as well as Yakutat will
likely see IFR conditions through the period, particularly near
Taiya Inlet due to low CIGs. Otherwise a majority of the panhandle
have improved to VFR conditions, with MVFR conditions primarily
due to any convective showers.

While just outside the current TAF window, the southern panhandle
can expect deteriorating conditions late Monday night into Tuesday
morning from a system moving up from Haida Gwaii.

&&

.MARINE...
Outside: Wind directions over the outside waters look to start off
out of the SE, then steadily back to the east as low pressure
shifts to near Haida Gwaii. This low looks to cause some enhanced
winds to around 15kt out of Dixon Entrance. The northern gulf
coast is expected to keep 10kt or less winds for much of the
coming week, variable at times with directions shifting due to sea
breeze influences. As high pressure builds over the central eastern
gulf early Tuesday, NWLY winds increase along the southern outer
coast to around 15kt. A new low pressure moves into the central
gulf Wednesday through Friday. Winds have been increased 20-25kt
as result, but some models show winds with this low up to 35kt
with this system, so will need to monitor.

Inside: Wind directions through the inside waters will be
diurnally influence by sunshine most of the week, meaning light
drainage winds in the morning, shifting to a sea breeze 10-15kt in
the late afternoon. Biggest challenge today was enhanced winds
near Eldred Rock reporting 20-25kt. The M/V Hubbard confirmed this
on their way to Haines/Skagway and the forecast was adjusted up
to keep the small craft advisory going into the early evening. As
low press moves over the southern gulf this week, winds through
the inner channels will want to turn out of the north.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Small Craft Advisory for PKZ012.

&&

$$

SHORT TERM...GJS
LONG TERM...Ferrin/GJS
AVIATION...STJ
MARINE...Ferrin

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