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000
FXAK68 PAFC 141318
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
518 AM AKDT Sun Apr 14 2024

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
This morning through Tuesday)...

Overall, the current forecast remains on track, with slight
adjustments made to winds and temperatures through Tuesday. The
vertically stacked low in the northern gulf continues to move
southward, ending existing showery conditions around Prince
William Sound later this morning.

Conditions will continue to improve over the next few days as a
building ridge moves into Southcentral. Clearer skies for most of
the region will persist through Monday night, allowing for daytime
highs to reach into the mid to upper 40s for some locations. While
temperatures will be warmer in the afternoon, the clear skies will
allow overnight lows to drop down into the mid to low 20s. The
only concern for today is localized offshore gap winds near
Seward, Whittier, and the Kamishak Gap, with expected wind gusts
of 40 mph or greater. As the ridge centers over Southcentral this
afternoon/evening, the existing pressure gradient over the gulf
coast will subside, ending the period of stronger gap winds.

By Monday night, a North Pacific Low will move northward towards
Kodiak Island. The prevailing flow will switch southwesterly in
the process, returning cloud clover to most of the area by Tuesday
morning. This shift in wind direction will also support upslope
precipitation along the eastern Kenai Peninsula, Prince William
Sound, western Alaska Range, and the gulf coast side of Kodiak
Island. Heavier precipitation along Kodiak Island is expected
Tuesday afternoon/evening as the low`s front passes through. There
are some model differences in the arrival of the front, as the
timing of the ridge`s displacement over Southcentral is still
unclear.

-BS

&&


.SHORT TERM FORECAST SOUTHWEST ALASKA, BERING SEA, AND ALEUTIAN
ISLANDS (Days 1 through 3)...

Light snow showers will continue to wind down this
morning across the Kuskokwim Delta as broad ridging builds over
Southwest Alaska. Under this ridge, expansive cloud cover will
help to moderate temperatures this morning with most areas across
the Southwest and central Aleutians only dropping into the mid 20s
to lower 30s. Clearer skies over the AKPen have allowed
temperatures there to drop into the teens to lower 20s, but should
see cloud cover gradually increasing through the day today. The
ridge axis will shift east over the greater Bristol Bay area and
AKPen by this evening with the possibility of patchy fog
developing tonight; however, increasing cloud cover may limit fog
potential.

The weather feature of note in the near term is a potent North
Pacific low that is currently moving into the far western Aleutians
this morning. Over the past 24 hrs, the Canadian and ECMWF have
jumped on board with the GFS and NAM to track the low along the far
western Aleutians before lifting north near Amchitka into the Bering
and north towards St. Matthew Island. While models have come into
better agreement with the track, the GFS and NAM still have a much
stronger low developing and have continued to trend the forecast
towards this solution. As the low deepens today, storm-force winds
will develop along the central Aleutians and may reach as far as the
eastern Aleutians tonight into early Monday. Rain or a rain/snow mix
will be common as the front moves across the Aleutians. The
Pribilofs will likely see precipitation start out as snow with a
change-over to a rain/snow mix as warmer temperatures work in. As
the front lifts towards coastal Southwest Alaska, temperatures
should remain cold enough for all snow as the system will be fully
occluded by then. Strong winds will accompany this system as it
moves across the Bering towards Southwest Alaska, and the potential
for blowing snow will be high Monday afternoon for Nunivak
Island, the Kuskokwim Delta Coast, as well as for the Western
Capes of northwestern Bristol Bay.

&&


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

The long term period will begin with a deepening North Pacific
low south of the Eastern Aleutians on Wednesday. Strong northerly
flow across the Bering, associated with the passage of several
shortwave troughs, will promote gusty conditions, scattered snow
showers, and below normal temperatures across much of the Bering
and the Aleutians. At the same time, a front is forecast to lift
into the AKPEN and continue into the Gulf of Alaska and Kenai
Peninsula through Wednesday night. Southeast flow associated with
the front will bring warmer temperatures and precipitation from
the AKPEN and Kodiak Island to the Kenai Peninsula. Above normal
chances for a mix of rain and snow are forecast for Southwest
Alaska on Wednesday and Thursday. The North Pacific low is then
forecast to shift southward and further away from the region by
late Thursday, as each trough from the Bering digs the low further
and further south. Of note, potential exists for an atmospheric
river to be directed into the Kodiak Island region, with heavy
rain. Friday and Saturday will see precipitation begin to wane
as the low pivots even further away from the region. A weak front
moves into the Western Aleutians Friday night and Saturday but
dissipates by Saturday night.

-BL

$$



.AVIATION...

PANC...VFR conditions and light winds will persist through the TAF
period.

&&


$$