348
FXAK68 PAFC 140042
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
442 PM AKDT Thu Aug 13 2026

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

Currently, cloud cover is present over much of Southcentral this
is due to some moisture that flowed in despite strong ridging over
Southern Alaska. The ridge remains in place on Saturday and drier
conditions prevail. This will allow for temperatures to reach the
mid to upper 70s for inland areas. The Susitna Valley around
Talkeetna and the Talkeetna Mountains could see isolated
thunderstorms from elevated instability, but the region may be too
dry to see this realized. The rest of Southcentral will be mostly
sunny. By Sunday, the ridge will be pushed eastward from a
shortwave from the west and a shortwave dropping from the north.
The northern shortwave will provide instability and lift for
thunderstorm chances (30 to 50%) in the Copper River Basin. The
greatest chances for thunderstorms will be north of Glennallen.
There is also a slight chance of thunderstorms for the Susitna
Valley on Saturday. There is uncertainty on how far the shortwave
from the north will drop on Saturday. If it drops further south,
there will be better chances for thunderstorms.

Moving into Sunday, a pattern shift takes place as a strong low
moves over Bristol Bay, driving a strong front into Southcentral.
The front will bring rainfall into Kodiak Island and into Coastal
Southcentral. Depending on the orientation of the front, more or
less rainfall will make it into the mainland. The Copper River
Basin, however, will remain drier at this point. Gusty gap winds
around Kodiak Island will occur, with the possibility of gap
winds for inland areas such as the Turnagain wind.

-JAR

&&

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

Broad southerly flow continues across Southwest Alaska this
afternoon and evening as an upper-level low remains in the central
Bering Sea and slowly moves south towards the southwestern Bering
through Friday. There is also an upper-level low in the North
Pacific that is poised to lift to the Alaska Peninsula (AKPEN) by
Friday and across the Southwestern Mainland through Saturday.
Showers within the broad southerly flow will taper off across
Southwest through tonight.

The upper-level low in the North Pacific, previously mentioned,
will be the focal point for active weather across Southwest for
Friday and Saturday. High temperatures will warm into the middle
to upper 70s across the interior with 60s to near 70 for the coast
Friday and Saturday. The warm temperatures, along with moisture
at the surface with dew points in the upper 50s, will allow for
instability to build Friday and Saturday afternoons. This setup
will allow for showers and thunderstorms to develop across across
the Southwestern Mainland. The focus for showers and storms Friday
will be along Interior Bristol Bay and the Interior Kuskokwim
Delta. The focus for showers and storms move a little more inland
on Saturday with the Kuskokwim Valley and Lime Village joining
Interior Bristol Bay and Interior Kuskokwim Delta with increased
lightning activity. Due to the nature of this moist, unstable, and
somewhat tropical airmass overhead for Friday and Saturday, some
of the storms could persist into the overnight hours.

Looking farther out west, the upper-level low, in the currently
in the Bering, will bring showers at times for Adak/Atka Friday as
it moves to and over the Central Aleutian Chain. This upper-level
low will interact with a stronger shortwave lifting northward
through the North Pacific Saturday morning. This interaction will
produce a swath of steadier and heavier rain across Adak/Atka for
much of Saturday. The front associated with the surface low will
also bring moderate to heavy rain to the Eastern Aleutians and the
southern AKPEN through Saturday. Wind-wise, still expect a
corridor or easterly to southeasterly sustained gales across the
marine zones on the Pacific-side of the Eastern Aleutians and
southern AKPEN Saturday. Some southeasterly gales make it into the
southeastern Bering and Bristol Bay Saturday evening and Sunday.

The low center itself moves into the southern Bering by late
Saturday night to early Sunday morning. Rain and gusty
northeasterly winds move into the Pribilof Islands by Sunday
morning. Rain and southeast winds also move into the Southwestern
Mainland by early Sunday morning as well with Dillingham and King
Salmon the first to see the effects of the front. Rain advances
north to Interior Bristol Bay and the Kuskokwim Valley by mid to
late Sunday morning. The Kuskokwim Delta will be showery at times
Sunday, but downslope southeasterly flow will limit steadier rain
from making it into the area. Rain continues across Southwest, the
AKPEN, and the Pribilof Islands Sunday afternoon and through
Sunday evening. Stay tuned for forecast updates regarding the
thunderstorm forecast for Friday and Saturday across the Southwest
Mainland, and for updates to the evolution of the North Pacific
low poised to lift into the Bering for Saturday night and Sunday.

&&


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

By Monday morning, there is general agreement a ridge will be
over the Alcan border into the Alaska Panhandle while a vertically
stacked low will be over the Y-K Delta with its front over the
northern Gulf and southern Southcentral. By this point, rainfall
will likely be ongoing for much of Southwest/northern AKPen and
Southcentral west of the Chugach and Talkeetna Mountains/Prince
William Sound. This rainfall may be heavy for Southwest, the
Susitna Valley, and the northern Gulf Coast. The front, as well as
shortwaves rotating around the low, will push the ridge further
into Canada on Monday. Any remaining areas with warm temperatures
will begin a cooling trend on Monday. The Copper River Basin may
still see high temps in the 70s if frontal progression is slow
enough to keep the ridge close, but all other places will only top
out in the mid to upper 60s. Rainfall progresses eastward to
coastal locations east of Prince William Sound on Monday as the
front moves onshore. Winds offshore the northern Gulf Coast may be
up to gale- force Monday morning.

Though models diverge with progression of the low after Monday
(some maintain it as a low over the Seward Peninsula, others open
the low up into a trough), the general pattern looks to remain
wet through the week for both Southwest and Southcentral Alaska as
shortwaves continue to rotate around into southern Alaska. Heaviest
precip will likely be along the western Alaska Range into the
Susitna Valley on Tuesday and the northern Gulf Coast through
Wednesday. Temperatures will also continue to cool throughout the
week.

For the Bering, Aleutians, and southern AKPen, shortwaves rotating
around the low to the north will likely maintain overcast skies
with occasional showers through the week.

-PA

&&


.AVIATION...

PANC...VFR conditions and light winds will persist.

&&


$$

866
FXAK67 PAJK 132356
AFDAJK

Southeast Alaska Forecast Discussion
National Weather Service Juneau AK
356 PM AKDT Thu Aug 13 2026

.SYNOPSIS...

Key Messages:

- Suicide Basin has released. Major flood stage on Mendenhall
Lake and River was reached Thursday morning with a crest of 14.7
ft around 2:15pm Thursday afternoon.

- Very warm temperatures to end the work week with highs in the
mid 70s to lower 80s.

- The warm and dry conditions will bring elevated threat for fire
starts across much of SE AK. A few small fires have been
observed already over the past week.

&&

.SHORT TERM.../through Saturday night/...Warm temperatures,
mainly clear skies and mostly dry weather will dominate the short
term period. High pressure out of the Gulf has weakened slightly,
with weak surface troughing and offshore northerly and easterly
low-level flow, allowing for drier and warmer interior airmass to
build into the panhandle. High temperatures will max out on Friday
as 850mb temps up to 15C and full sun will allow for very warm
interior temps away from the coast to climb into the upper 70s to
possibly as high as the mid 80s. Heat Advisories are in effect
through Friday. Locations near the coast will likely climb into
the mid and possibly upper 70s before any sea breezes kick in by
the afternoon and bring cooler marine air back inland. Still warm
but slightly cooler for Saturday as ridging begins to builds back
towards the coast and 850mb temps drop a couple of degrees as
cooler marine air starts to build back inland. High temps are
still expected to reach the 70s to possibly low 80s with mostly
sunny skies. Additional Head Advisories may be needed. Each
afternoon/evening, convection will fire up east of the coastal
mountains in western BC and Yukon and drift west towards the
border. This afternoon, a few showers have fire near and east of
Hyder and could drift west through the evening towards Ketchikan,
but the threat is limited. No thunder expected we are lacking
significant moisture and lifting mechanism. Friday and Saturday
will see a slightly better potential for showers and thunderstorms
to drift into the southern panhandle, mainly for Hyder, Ketchikan
and Misty Fjords. Any rain amounts will be light as the warm and
drier low levels will bring high cloud bases and limit the
potential for a wetting rain. Dangerous cloud to ground lightning
and gusty winds are possible with any thunderstorms. Any marine
layer stratus development will likely be limited along and just
off the outer coast.

.LONG TERM.../Sunday through Wednesday/...The upper level ridge
is expected to begin to dissipate Sunday as a weak trough builds
over the gulf, shifting the region toward zonal flow that will
bring cooler, more saturated air onshore. Temperatures are
expected to follow a cooling trend, due to 850mb level temps
dropping, and leading to daily highs in the mid 60s by next week,
though inland and southern areas may remain warmer in the low 70s
due to the residual influence of a weakening surface ridge. As
surface high pressure also weakens, a series of weak frontal bands
originating from a surface trough dropping into the gulf from the
Alaska Peninsula will move across the panhandle, resulting in
widespread overcast skies and moisture advection in the low to mid
levels. The northeast gulf coast, particularly near Yakutat, will
be the primary focus for precipitation, with the most significant
activity expected between Monday and Tuesday. While deterministic
models show some spread still, the highest forecaster confidence
results in 24 hour rainfall accumulations of 0.75 to 1.25 with
this disturbance. The remainder of the week is expected to stay
showery with lighter, intermittent rain and cooler temperatures
across the panhandle, offering relief from the recent dry spell.

&&

.AVIATION.../ Through Friday afternoon/...

VFR conditions dominate SEAK for the next 24 hour TAF valid
period. Offshore flow will keep most marine layer clouds out to
sea, leaving cigs either non-existent or very high, in the case
that clouds form during peak heating Friday afternoon. A dry
atmosphere should also serve to limit cloud formation. Winds are
generally light and should remain under 10kts.

&&

.MARINE...
Outside: High pressure over the Gulf keeps a tighter gradient
over the eastern waters. Moderate to fresh breezes for the outer
coastal waters through tonight. Winds will gradually diminish on
Friday, becoming a gentle to moderate breeze that will remain
into the weekend as the high weakens and gradient relaxes. Wave
heights of 4 to 6 ft will diminish slightly through the weekend.
Seas will diminish about a foot by Friday and continue into the
weekend. Main marine concern for outer and coastal waters will be
nightly return of marine layer, with fog and low stratus offshore.
Winds and seas look to trend back upward by early next week as a
change in weather pattern brings a low and front into the Gulf.

Inside: Weakening high pressure out in the Gulf will allow for
moderate to fresh N to NWly to trend downward as the gradient
weakens across the panhandle. Winds will become light to gentle
and more N to NEly by Friday low pressure sitting south of the
panhandle and troughing drifting west. Lynn Canal will likely see
moderate to fresh northernly with the tightened N-S gradient
remaining. Light to gentle winds should continue into the weekend
with occasional moderate winds for Lynn Canal. Winds will become
more onshore through the weekend as the high pressure builds east
towards the panhandle. Slight chances remain for isolated
thunderstorm development from Canada moving into the southern
panhandle this evening, but especially on Friday and Saturday
Friday afternoon/evening, primarily near Misty Fjords and Clarence
Strait. Gusty winds and lightning would be possible if any
thunderstorms make it into the area.

&&

.FIRE WEATHER...High pressure out the the Gulf continues to bring
mostly dry and warm weather across the panhandle. Warm
temperatures with daytime highs reaching the 70s to mid 80s and
dry weather are expected to continue through the end of the week
and into the weekend. More inland areas are expected to continue
reaching relative humidities down to the 30s to 40s during the
daytime hours with rebounding during the overnight hours into the
80s to 90s. With the continued lack of rain, fine fuels such as
grasses will continue to dry.

Models continue to suggest the potential for isolated
thunderstorms along the Panhandle border with Canada as well as
the SE panhandle on Friday and Saturday during the
afternoon/evening.However, due to the lack of low level moisture
each day the chance of thunderstorms is still only around 15% or
less.

Overall, expecting the dry and warm trend to continue through the
end of the week with fire weather conditions looking to last into
the weekend as well, however the main variable to watch for will
be daytime winds. As of now, expecting the worst fire weather
conditions to be Thursday and Friday afternoon, however given the
persistent pattern can`t rule out this extending further into the
weekend. The dry conditions are looking to last through the
weekend, with the next chance of rain not being until Monday.

.HYDROLOGY...The Mendenhall River crested around 2:15pm this
afternoon with a height of 14.7 ft. The river will continue to
drop through the afternoon and evening tonight before exiting
flood stage during the overnight. Levels in Suicide Basin could
still continue to fall somewhat even though the release has
stopped but should come to a steady here eventually. The water in
the Mendenhall river basin will continue to drain out but will
take some time to move from the lake down to below Brotherhood
bridge.

&&

.AJK WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Heat Advisory until 7 PM AKDT Friday for AKZ318-319-321-325-328-
330>332.
MARINE...None.

&&

$$

SHORT TERM...DS
LONG TERM...BAS
AVIATION...VFJ
MARINE...DS
FIRE WEATHER...AP/DS
HYDROLOGY...SF

Visit us at http://www.weather.gov/Juneau