736
FXAK68 PAFC 070039
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
439 PM AKDT Thu Jun 6 2024

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

An upper-level trough centered over the southern Bering Sea today
continues to serve as the main driver for weather across Southern
Alaska, spinning shortwaves through our area. This afternoon saw
the development of continued rainfall across Prince William Sound
coastline, as well as several thunderstorms develop in the Susitna
Valley. Going into tonight, thunderstorm activity will begin to
diminish beginning in the early evening, coming to an end tonight.
Similarly, the trough pushing rainfall and gusty winds into
Prince William Sound and through it`s gaps will begin to weaken
and diminish by Friday morning, coming to an end by Friday
afternoon.

Mainland Southcentral will see a general shift towards warmer and
calmer weather. By Friday afternoon, mainland Southcentral is
expected to seeing some clear skies, and by Saturday afternoon,
the highest temperatures of the season so far are possible, with
much reaching 70 degrees in the afternoon. Coastal Southcentral
however, near Prince William Sound and the southern Kenai
Peninsula, are expected to see a return to cloudier and rainy
conditions as early as Saturday evening due to a shortwave pushing
up from the central Gulf of Alaska. Saturday will also likely not
be as sunny as Friday due to clouds spilling over across the area
from our system to the South.

A focus of the forecast for the next few days will be for Kodiak
Island as a series of shortwaves approach and sit over the area
bringing continued moderate rainfall with periods of heavy
rainfall beginning Friday afternoon. This system has the potential
for to create a prolonged rainy pattern for Kodiak Island,
continuing at least through the weekend, potentially into early
next week. For Kodiak City, 2 to 4 inches of rainfall is possible
over the course of Friday afternoon until Sunday afternoon.

-CL

&&


SHORT TERM FORECAST SOUTHWEST ALASKA, THE BERING SEA AND THE
ALEUTIANS (Days 1 through 3: This afternoon through Sunday
afternoon)...

Unsettled weather continues through the weekend. A broad, upper
low currently near the Eastern Aleutians will serve as a focal
point, with upper level shortwaves rotating around it and driving
weather across the region through Saturday. By Saturday afternoon,
it merges with an approaching low from the North Pacific and
moves southeastwards towards the Gulf of Alaska. Some minor
uncertainty persists with the timing and magnitude of winds and
precipitation as models attempt to hone in on weaker surface lows
associated with this upper low. Here are the hazards/notable
weather currently being monitored:

* Slight chance for thunderstorms in the Lower to Middle
 Kuskokwim Valley (near Lime Village, Stony River, and Sleetmute)
 through this evening.

* Periods of moderate to heavy rain (with storm totals hovering
 around 0.5 to 1 inch) likely on the Pacific side of the Alaska
 Peninsula as several waves of precipitation move in through the
 weekend.

* Several rounds of gusty east-to-southeast winds, with gusts as
  high as 40-50 mph, for interior Bristol Bay through the weekend.

* Daytime highs climb into the high 60s and low 70s this weekend for
  communities along Kuskokwim River.

-KC

&&

.LONG TERM FORECAST (Days 4 through 7) Monday through Thursday...

A couple of significant changes over the Alaska Weather Map
through Thursday. A Rex block builds from the Arctic into Mainland
Alaska through the period. This continues to support surface
thermal troughs over the Eastern Interior. One closed low wobbles
over the Gulf of Alaska and the Eastern North Pacific as it
weakens. A low center entering the Western Bering slips along the
Aleutians and merges with the Gulf low for Wednesday. With a ridge
forming over the Kamchatka and Chukotsk Peninsula, a third center
from the North Pacific with its front enters the pattern over the
Central Aleutians on Thursday. A blend of Canadian/ECMWF/GFS and
UKMET carries good confidence for the first half of the forecast,
with the EC and GFS straying from the group by the end of the
forecast.

The Gulf low aloft links up with a well developed surface system
for Monday and Tuesday. Locally heavy rainfall is expected across
coastal Southcentral Alaska, with the highest amounts along the
Eastern Kenai, Kodiak Island and parts of the Alaska Peninsula for
the beginning of the week. Gusty winds less than gale force will
occur along the North Gulf Coast, with gale force winds through
the Barren Islands and Shelikof Strait for Monday, diminishing
early Tuesday. Lesser amounts of rainfall moves inland to the
Alaska Range, and along the West Coast down to Bristol Bay. The
Aleutians and Bering will continue rain showers, with locally
gusty winds across the Central Aleutians through Tuesday. Another
area of gusty winds moves across the Pribilofs through Wednesday.
Another area of locally heavy rainfall comes in over the Western
and Central Aleutians with a low and its front late Wednesday into
Thursday, spreading East through the week.

-Kutz

&&

.AVIATION...

PANC...VFR conditions will persist throughout the TAF period.
A surface trough will continue to move northwest across the Kenai
Peninsula and into the Susitna Valley through this evening.
Turnagain Arm winds bending back over the terminal will continue
to increase into the evening with peak gusts approaching 30 kts.
These winds will diminish quickly by late evening, becoming light
and variable overnight. An isolated shower is still possible
through late afternoon; however, any reduction to ceiling and
visibility with is not anticipated. Turnagain Arm winds are
expected to bend back over the terminal by around noon again
tomorrow. Wind gusts tomorrow afternoon are not expected to be
nearly as strong as today, though.

&&

$$