598
FXAK68 PAFC 110018
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
418 PM AKDT Mon Aug 10 2026

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

Key Messages:

- The Heat Advisory for the Lower Mat Valley including Wasilla,
  Palmer, and Big Lake has ended, with marginally cooler
  temperatures returning to the Mat Valley through Tuesday.


- Warm temperatures continue today before cooler conditions arrive
  Tuesday. A warming trend then develops Wednesday and continues
  into Thursday as upper-level ridging rebuilds across
  Southcentral


Discussion:

Satellite imagery shows areas of marine fog and low stratus across
portions of Cook Inlet and adjacent coastal areas, with high
clouds also moving across portions of Southcentral. High
temperatures will gradually reach the 60s along the coast and the
70s farther inland. Afternoon and evening showers will remain
largely confined to higher terrain as weak shortwave energy moves
southward from the Interior. While thunderstorm potential remains
low, an isolated lightning strike or two can not be ruled out
across the Copper River Basin and portions of the Southcentral
Interior. Otherwise, stable conditions along the coast and in the
valleys will favor mostly dry weather.

On Tuesday, the upper-level ridge shifts father west as weak
shortwave energy moves across Southcentral. Low-level flow will
become more southerly, allowing a stronger push of marine air into
Cook Inlet and adjacent areas. Marine fog and low stratus may
extend inland during the morning, particularly across the western
Kenai Peninsula, Anchorage, and portions of the Mat-Su Valleys.

By Wednesday, shortwave energy becomes more diffuse as upper-
level heights begin to rise across Southcentral. Southerly low-
level flow may continue to support areas of morning marine fog and
low stratus around Cook Inlet and the western Kenai Peninsula.
However, clouds should gradually diminish through the day, with
increasing sunshine and rising heights allowing temperatures to
rebound from Tuesday`s cooler readings. Meanwhile, a North Pacific
low approaching the Alaska Peninsula and Kodiak Island will
increase precipitation chances and breezier conditions around
Kodiak Island.

The warming trend continues Thursday as upper-level ridging
becomes more established across Southcentral while the more
active trough and North Pacific low remain primarily to the
southwest. Rising heights and increasing sunshine will support
another increase in temperatures, especially across inland
locations. Coastal areas may remain somewhat cooler where marine
influence persists, with additional overnight and morning fog or
low stratus possible near Cook Inlet. Moisture associated with the
North Pacific system may approach the southern Kenai Peninsula,
but the building ridge should limit its northward progression,
keeping most of Southcentral dry through Thursday.

LM

&&


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

Low stratus from last night and early this morning continues to
erode this afternoon across Southwest Alaska. Looking at satellite
imagery, there is a mesoscale shortwave lifting over the
Kuskokwim Delta with a trailing shortwave behind it over Bristol
Bay. These two features are moving around the western periphery of
the upper-level ridge that is situated over the interior. With
low stratus continuing to erode along the Kilbuck/Kuskokwim
Mountains and instability beginning to build with afternoon
heating, showers are likely (60% chance) to fire up along those
mountain ranges. Some short-range hi-res guidance depict a few
stronger and more robust showers developing by early evening. Any
lightning that occurs with these showers should remain mostly
confined to the mountain ranges (Kilbuck/Kuskokwim Mountains).

Tuesday will feature a better day for instability to build and
warmer temperatures across Southwest. For high temperatures
Tuesday, expect low to middle 70s inland with 60s along the coast.
In conjunction with afternoon heating on Tuesday, another
shortwave will lift over the Southwestern Mainland and will help
to kick off another round of showers and thunderstorms. The
Kilbuck and Kuskokwim Mountains will have the best shot for
lightning with this round as well. Some of these showers and
storms may also advect off the terrain and to in and around the
Bethel area with southerly to south-southeasterly steering flow.
However, instability could be strong enough in the valleys of
Interior Bristol Bay (Koliganek/New Stuyahok) for some showers and
isolated storms to form (30% chance). Lightning activity will
taper off during the evening hours as heating is lost and with the
days becoming shorter.

For Wednesday, the upper-level ridge will re-orient in a north-
south fashion and be placed over the eastern Copper River Basin of
Southcentral Alaska. This will allow for southerly flow to be
introduced across Southwest. The airmass advecting in from the
North Pacific will be cooler and more stable. Therefore, any
showers that occur Wednesday afternoon will have little to no
lightning threat (less than 10% chance of lightning).

Farther to the west, a weak surface low currently moving off of
the Kamchatka Peninsula will make its way into the western Bering
Sea by Tuesday morning. Winds associated with this low will remain
small-craft with some gale-force southeasterly gusts along the
Western and Central Aleutians. This low will also spread rain from
the Western Aleutians to the Central Aleutians Tuesday and
Wednesday. Nikolski/Unalaska/Akutan will see scattered showers
Wednesday and less in the way of steady rain like the Western and
Central Aleutians due to surface high pressure lingering in the
eastern Bering.

A North Pacific low looks to send its front northward into the
Pacific-side of the Alaska Peninsula (AKPEN) through Wednesday.
Coupled with southerly to southeasterly flow aloft, rain will be
enhanced at times for locations such as Chignik and Perryville.
Rain will be more showery and scattered for the Bering side of
the AKPEN due to the downslope southerly to southeasterly flow.
Rain from this system makes it into Mainland Southwest (Bristol
Bay/Kuskokwim Delta) by early Wednesday evening. Rain continues
for Bristol Bay and the Kuskokwim Delta through much of Thursday
before slowly tapering off to scattered showers Thursday evening.
Showers will continue across the Pacific side of the AKPEN with
southerly to southeasterly flow persisting through Thursday. By
Thursday afternoon and evening Upper-level energy from Kamchatka
and Siberia move into the Bering and consolidate which will form a
new Bering low in the west-central Bering with showers and low
stratus likely for the Pribilofs by then.

&&


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

The general pattern starting Friday will have an upper level low
reside over the central Bering with a ridge over Mainland Alaska.
A surface front lingering from Southwest Alaska to the Gulf may
maintain some showers through the day across the Bristol Bay coast
to areas along the northern Gulf Coast. Kodiak Island and the
Pacific side of the AKPen will also see rainfall continue with
upsloping winds. Most of Southcentral and parts of Southwest,
especially north of the Cook Inlet/Chugach Mountains, and the
Kuskokwim Valley will be warm and dry Friday. Out west, a surface
low occludes in the western Bering on Friday, maintaining
scattered showers and up to small craft winds for much of the
Bering.

By Saturday, the upper low begins to move to the eastern Bering
and makes an attempt to push the ridge northeastward into the
Interior/Yukon down through the Alaska Panhandle. Temperatures
across the region will begin to cool as cloud coverage increases
from west to east. Temperatures in the Copper River Basin will
still be warm Saturday with the ridge still overhead keeping
clouds away.

A surface low from the North Pacific will move through the
Aleutians/AKPen into Southwest Alaska Saturday and Sunday. This
will be conducive for rainfall throughout the weekend, which may
be heavy at times. There are model differences with both the
strength of the low and whether the low takes a more northerly
track through the eastern Bering into the Southwest Coast or a
southerly track starting south of the AKPen before moving into
Bristol Bay. Depending on the strength and track, southeast winds
through particular gaps and bays like Cold Bay could also be
strong Saturday through Sunday. Either way, this low also looks to
send a front into the Gulf Saturday evening through Sunday. This
will likely also promote rainfall (possibly heavy) and potentially
strong winds for Kodiak Island and the southern Kenai Peninsula.
As the front continues northward on Sunday, precipitation looks to
spill over into the rest of Southcentral and Southwest and linger
into Monday. Details about this weekends system will become more
clear in the coming days.

-PA

&&


.AVIATION...

PANC...While the marine layer has burned away for this afternoon,
lower ceilings and areas of fog will likely return later tonight.
Visibilities could decline as early as about 08Z tonight, though
confidence is lower with the likelihood and timing of fog.
Confidence is higher that low clouds will move up Cook Inlet and
over the terminal by around 12-15Z early tomorrow morning,
dropping ceilings to low MVFR for much of the morning. Winds will
remain light and variable throughout the TAF period.

&&


$$