FXAK68 PAFC 201357

AFDAFC



Southcentral and Southwest Alaska Forecast Discussion

National Weather Service Anchorage AK

557 AM AKDT Sat Jun 20 2026



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



Key Messages: 



* Showers and thunderstorms return this afternoon, primarily for

  the Matanuska-Susitna Valley and the Copper River Basin.

  Coverage of the thunderstorms are expected to be less than

  yesterday. If you hear thunder or see lightning, seek shelter.



* Convection decreases over the next few days. A low approaching

  Kodiak will bring rain today through Monday. There is low

  confidence with how far north the front will affect mainland

  Southcentral and when it would arrive.



Discussion:



An easterly wave is moving showers through the Copper River Basin

this morning. Some of those showers have moved through the lower

Matanuska Valley. A weak trough just south of the easterly wave is

across Prince William Sound with a few showers and low stratus

lifting northwestward. Showers will continue for the Copper River

Basin and midday heating will allow for isolated to widely

scattered thunderstorms. Confidence with this forecast is medium 

to high (70-80%). The highest potential for thunderstorms will be

through the Copper River, north of Chitina up to the Alaska Range. 



Meanwhile, a weak North Pacific low will lift a front northward 

across the western Gulf, bringing rain to Kodiak Island today and

lasting into early next week as the low hovers south of the

Island. The front will continue to lift to mainland Southcentral.

The ridge over that is currently over the Gulf will get pushed

along the Gulf coast Sunday. South to southeast gap winds will 

increase later on Sunday, including through Turnagain Arm, Knik

River, and Copper River.



Model agreement breaks down on Monday, a complex low appears to

form as the low dipping south across the eastern Bering Sea

interacts with the North Pacific low. This could allow some

movement of the low system south of Kodiak to hedge into the Gulf

of Alaska where broad troughing sets up. Rain showers is expected

to lift north across the Gulf this weekend through Monday, though

with poor model consensus, confidence is low with the timing and 

northward extent of the rain coming from the parent low to

Southcentral. At this time, it appears that there is a weak wave

that reaches the coast Sunday morning and a more wet wave for

Monday morning. 



&&





.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS 

(Days 1 through 3: Today through Tuesday morning)...



Afternoon/evening thunderstorms across interior Southwest Alaska

will continue through the weekend. Meanwhile, for coastal 

Southwest, Alaska Peninsula, and Bering Sea/Aleutian Islands, 

areas of dense fog and low stratus remain likely as a ridge of 

high pressure lingers in the Bering Sea through Monday morning. 



Thunderstorms today will be more widely scattered compared to 

Friday's storms as the line of instability is pulled apart between

the southward moving low in the eastern Bering and southerly flow

into the Alaskan interior. The low crosses the Alaska Peninsula 

by Sunday morning to join another low southeast of Kodiak. This 

will orient the upper level flow from southeast to northwest 

across the interior and bring additional shortwaves into 

Southwest, however, reduced surface heating will inhibit, but not 

completely shut down, thunderstorm formation.



Further west, the front will likely bring winds 25 to 35 kt along

the Aleutians. Steady, light rain will lift across Shemya on 

Sunday morning, and Atka by Monday morning before weakening 

Tuesday morning.



&&

.LONG TERM FORECAST (Days 4 through 7: Tuesday through 

Friday)...



Next week will see unsettled weather for Southcentral Alaska and

the Aleutians. Low pressure over the Gulf will allow for increased

cloud cover over much of Southcentral with showers throughout the

week. A Bering Sea low will slowly track eastward bringing 

periods of rain and gusty winds for the Aleutians before crossing 

the island chain and getting swept into more dominant westerly 

flow aloft.



High pressure system over the central Bering Sea will result in  

generally fair weather for the Alaska Peninsula and Southwest 

Alaska, but these areas could still see afternoon showers

developing along the western slopes of the higher terrain. 



The track of the Bering low becomes more uncertain late in the 

next week. Model consensus remains fairly high as the Bering Sea 

low moves towards the Aleutians midweek, but confidences lowers 

with the position of the upper low as it begins to cross the 

Aleutians by late in the week.



-SS/PP



&&

.AVIATION...



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



&&





$$