National Weather Service Raw Text Product

833 
FXAK68 PAFC 220054
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
454 PM AKDT Sat Jun 21 2025

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

Discussion:

Hot, dry, windy conditions continue this afternoon in the Copper 
River Basin, where a red flag warning remains in effect until 10
PM AKST this evening. A pattern change is on the horizon as an 
upper level ridge continues to move east into Canada, allowing a 
large low in the southern Bering to increase southerly flow into 
Southcentral. This will bring several shortwave troughs up 
through the Gulf. Model agreement remains poor to moderate 
concerning the timing and strength of these waves, however, 
southerly flow will increase cloud cover, lower temperatures 
slightly, raise the relative humidity, and improve air quality by 
evacuating residual haze of the past several days.

The NAM and ECMWF are most in agreement that Light rain will 
start this afternoon across the eastern Kenai Peninsula and 
continue through Sunday. By early Monday morning, southeasterly 
flow brings rain into Cordova, Valdez, and potentially the Copper
River Basin with lower chances (due to downsloping) for the 
Anchorage bowl and MatSu regions by the afternoon. A second wave 
also sweeps across Kodiak late Monday, which intensifies and moves
north into Cook Inlet by Tuesday morning. 

&&

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

An upper level low spinning just north of the Central Aleutians 
is becoming vertically stacked with a nearby 996 mb surface low. 
Although the surface low has reached maturity and has begun to 
occlude, foggy and misty conditions will continue through the 
weekend for the Pribilof Islands. 

Onshore flow for coastal and parts of the mainland Southwest is 
causing areas of light rain for the Kuskokwim Delta. Fire danger 
levels are trending down for the short term due to light rain and 
cloud cover, although chances for wetting rain (0.1 inches in a 12
hour period) remain low. Temperatures will remain on the cooler 
side across Southwest due to the southerly flow off of the Bering 
Sea. Southeast winds through Kamishak Gap into Interior Bristol 
Bay and the Kuskokwim Valley will begin to diminish early this 
evening into the overnight hours. A warming trend will begin into 
the new work week as low-level to mid-level flow becomes more 
southeasterly Monday and into Tuesday. Clouds and showers will 
linger with upper level shortwaves lifting across the area from 
the North Pacific and Bering Sea.

Farther west, gusty southeast winds continue across the southern 
Alaska Peninsula (AKPEN), especially through Cold Bay, through 
Sunday evening before winds slowly begin to relax. Gusts should 
peak up to 45 mph this afternoon and evening. Showery conditions 
will also persist through the weekend and into the new work week 
across the southern AKPEN with low cloud ceilings and off and on 
showers across the Eastern Aleutians. Another front works eastward
from Kamchatka Sunday morning to over the western Bering and 
Western Aleutians by Sunday evening. Southerly gale-force winds 
are expected to accompany this front across the Western Aleutians 
before it quickly begins to fall apart and its winds weaken to 
small craft as it reaches the Central Aleutians Monday and the 
Eastern Aleutians, Pribilof Islands, and southern AKPEN Tuesday.
The heaviest rain is expected to be confined across the western 
Bering and Western Aleutians Sunday evening with light to moderate
rain across the Central Aleutians Monday and light rain across 
the Eastern Aleutians, Pribilofs Islands, and southern AKPEN for 
Tuesday. What is left of the front will merge with the remnants of
the aforementioned occluded low/trough heading into Tuesday.

-DN/AM

&&


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

We are beginning to get a little more motion in the weather 
systems across the Alaska region through the forecast period. A 
closed upper level low over the Central Bering begins its trek 
across the Alaska Peninsula into the Gulf of Alaska by the 
weekend. Several shortwaves rotating through the pattern help 
accelerate its movement, and help set up some Easterly wave 
conditions across Southcentral Alaska. The upper level ridge 
across the Northern portions of Mainland Alaska drift into the 
Arctic through Saturday. Forecast guidance begins with a 
deterministic blend of GFS / ECMWF and Canadian models that 
diverge early in the period, so a change to ensemble means will 
carry the large scale features through the rest of the forecasts.

Diminishing warmer temperatures over Interior Alaska helps draw 
down the possibilities of convective activity across the Central 
Alaska, with the last of the showers and thunderstorms occurring 
in the Eastern border zones. A slowly weakening surface low near 
the Pribilofs slips across the AKPEN into the Central Gulf of 
Alaska by the weekend. Windy conditions close to gale force slips 
over the Western and Central Aleutians for Wednesday. Gusty winds 
cross the Central Aleutians late Thursday into early Friday. 
Widespread rain over the Eastern Bering moves over Southwest 
Alaska, AKPEN and Kodiak Island through Friday and spread along 
the Southcentral coast through Saturday. Gusty Easterly winds set 
up over the Northern Gulf of Alaska late Friday into Saturday. A 
moderately strong North Pacific low approaches the Western 
Aleutians with rain for Friday before heading back into the North 
Pacific for Saturday.

- Kutz

&&

.AVIATION...

PANC...VFR conditions will persist. Southeast winds developing 
along the Turnagain Arm may bend into the terminal this evening, 
with occasional gusts up to 25 kts. However, there is still a
chance these Turnagain Arm winds don;t bend toward the north
enough to move over the terminal which would keep westerly winds
prevalent as they are the result of the eddy shearing off the 
core of stronger Turnagain winds. Either way, the winds will 
slowly diminish and become more southerly overnight into early 
Sunday morning.

&&


$$