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FXAK68 PAFC 291344
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
544 AM AKDT Sat Jun 29 2024

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

Discussion:

Not much change in the overall synoptic pattern through early next
week. Models are still in agreement will the Bering low dropping
south today before pivoting to the east this evening. Water vapor
imagery this morning indicates that the low is starting its dive
south with a shortwave trough on its eastern periphery lifting north
towards the Kuskokwim Bay. As the parent dives south, its attendant
front will push northward into the western Gulf...nearing Kodiak
Island by late tonight. Kodiak may see a slight improvement in
conditions before getting socked back in as the front nears.
Intermittent rain showers expected this afternoon before more steady
rainfall arrives by this evening. Models consensus on total rainfall
amounts differ quite a bit for Kodiak, but on the low end Kodiak
City could see a quarter inch through Monday and up to an inch on
the higher end.

The upper ridge will start to build back into the central interior
of Alaska with ridge axis positioning itself along to just north of
the eastern Alaska Range by Sunday. This will keep the highest
chances for thunderstorms north of the Alaska Range today and along
the slopes of the Alaska Range and Wrangell Mountains tomorrow,
though models are hinting that a low end instability axis might
extend over towards the Talkeetna Mountains and northern Susitna
Valley Sunday afternoon.

With the Bering low and front to the south and west, and the upper
ridge building back west to the north...Southcentral will see
increasing easterly flow resulting in a more unsettled pattern for
the latter half of the weekend into early next week. Rain showers
will become more widespread overnight tonight into Sunday morning
for the northern Gulf as remnant lows in the eastern Gulf become
easterly waves. More widely scattered showers expected for the
Copper River Basin and northern Susitna Valley. The eastern Kenai,
Prince William Sound, and northern Gulf coast will see the bulk of
precipitation as the western Kenai, Anchorage Bowl, and Mat-Su
Valley will likely see downsloping set-up with lesser chances for
any showers. Lastly, increasing pressure gradients along the Gulf
coast will result in gusty gap winds developing for the Turnagain
Arm and Copper Basin.

- PP

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA/ALEUTIANS
(Days 1 through 3: Saturday through Monday)...

Broad low pressure over the Bering continues to produce unsettled
weather for much of the Aleutian Islands and Southwest coast. For
the interior portions of Southwest, building high pressure will
result in mostly drier and warmer conditions through the weekend.
Afternoon showers will be possible in locations closer to the
western Alaska Range, but more stable air should help limit
thunderstorm activity through the forecast period.

A shortwave low passing along the Aleutians will move eastward
through the weekend before it becomes near-stationary around the
Alaska Peninsula late Sunday. In addition, the upper low in the
Bering will swing southward and merge with the shortwave by the
later portion of Sunday afternoon. The energy associated with this
merged system will continue to produce rounds of precipitation
for most of the eastern Bering/Aleutians, as well as the southwest
coast.

Beginning Sunday evening, a building ridge of high pressure will
enter the western Bering and push eastward through at least the
end of the forecast period. As the ridge moves eastward, most
precipitation behind the low will quickly taper off and become
more focused south of the Alaska Peninsula by Monday afternoon.
Expect a brief cool down over much of Southwest on Monday with
the presence of the low pressure system near the region.

-BS

&&
.LONG TERM FORECAST (Days 4 through 7)...

Low pressure in the Eastern Gulf of Alaska will slowly track to
the east producing unsettled weather across the Gulf. A ridge of
high pressure will continue to dominate South Central Alaska and
the Copper River Basin throughout the period bringing warmish
temperatures and dryer conditions over the region. Isolated to
scattered thunderstorms are possible along the Alaskan Range and
Copper River Basin through Friday afternoon.

-DD

&&



.AVIATION...

PANC...VFR conditions and light southwesterly winds will persist
through Saturday afternoon. Winds turn southeasterly early
Saturday evening and could see a brief period of 15 to 20 kt
gusts as the Turnagain Arm winds bend into the terminal before
bending back out towards Fire Island.

&&


$$