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FXAK68 PAFC 071307
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
507 AM AKDT Mon Apr 7 2025

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

Discussion:

The next round of precipitation has slowly been rotating westward
across the Chugach Mountains and northern Kenai Peninsula during the
overnight hours with rain showers transitioning to a mix and/or all
snow for Portage, Turnagain Pass, Anchorage Bowl and up towards the
Mat-Su Valley. Anchorage up through the Mat Valley were slow to
saturate, but we are now seeing light to moderate snow spread across
these areas. Some heavier bands of snow are also pushing west, and
these bands will likely result in reduced visibility and some quick,
but minor, accumulations. The Anchorage Bowl up through the Mat-Su
Valley is still on track for up to 2 to 3 inches through Tuesday,
with higher amounts looking to be focused near Portage and Turnagain
Pass where up to 6 inches is possible (higher amounts at higher
elevations). Most lower elevation coastal locations along the Gulf
and Prince William Sound remain warm enough that precipitations has
remained all rain, but Whittier and Valdez may see enough cold air
work in to get a mix or period of light snow.

The overall pattern does not change much in the near term as an
upper low near the Seward Peninsula ejects several shortwave troughs
southward across Southwest Alaska and the AKPEN and into the Gulf.
These lows will dip south towards the central Gulf before swinging
back up towards the northern Gulf Coast. This will allow for
continued unsettled weather for much of Southcentral this workweek.
Persistent northerly flow on the west side of the trough will help
to draw cooler air into the region and mostly snow showers for
inland areas of Southcentral and rain or a rain/snow mix for many of
the coastal Gulf zones.

- PP

&&


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

Relatively mild conditions currently exist across Southwest AK
and the Aleutians. A broad upper level trough extends from the
Chukchi Sea to the Gulf of Alaska bringing cold and dry northerly
flow into Southwest Alaska. Cold air advection will enhance gap
winds along the Alaska Peninsula today and keep temperatures
cooler through the first half of the week.

A fast moving low pressure system originating near St. Lawrence
Island will bring light snow and enhanced winds as it tracks
southeastward across Nunivak Island and the Kuskokwim Delta today
before crossing the Eastern Aleutians and Alaska Peninsula Tuesday
morning. This should be a fairly low impact system, but expect
lower elevations of the Alaska Peninsula to receive 1 to 3 inches
and higher elevations up to 6 inches by midday Tuesday. The
combination of snowfall and wind gusts up to 40 mph will
significantly reduce visibilities Tuesday morning before the wave
moves into the North Pacific later in the day. A small shortwave
descends across the Bering and Pribilof Islands on Wednesday,
forming a band of increased snow shower activity as it moves
towards the southern Alaska Peninsula Wednesday night.

&&


.LONG TERM FORECAST (Days 4 through 7: Thursday through Sunday)...

The weather through the long-term will mostly be characterized by
a mostly quiet pattern for the Bering Sea, Aleutians, and
Southwest Alaska. In contrast, the Gulf of Alaska, Kodiak Island,
and the mainland Southcentral Alaska coast will remain active.

Generally cooler weather is expected across mainland Southwest
Alaska through through the long-term with the best chance of
precipitation being on Thursday as an upper-level low originating
near the Bering Strait region continues to drop southward across
the Bristol Bay area. Any precipitation associated with this
feature would be light and mostly in the form of snow across
Southwest and the Alaska Peninsula (AKPEN). As this low dives
down across the AKPEN and into the North Pacific through Thursday,
this will help to enhance northerly winds through the the favored
terrain, bays, and passes across the AKPEN Thursday afternoon and
potentially persisting into the weekend as cold northerly flow
continues across the eastern Bering and mainland Southwest. High
pressure across the western and central Bering Sea looks to
persist into the weekend as well. This high pressure also looks to
help keep a lifting North Pacific low to the south of the
Aleutians on Friday. Although easterly to southeasterly winds will
pick up and be gusty at times, especially across the marine areas,
most of the area is expected to remain dry. The one exception is
that the front could briefly clip the Western Aleutians Friday
before it weakens and the high pressure across the northern Bering
moves south towards the area.

Meanwhile, across Southcentral and the Gulf of Alaska, confidence
is relatively high that the weather pattern will remain active,
especially across the coast and the Gulf. However, confidence is
low on the exact tracks and timing of each Gulf low through the
period. There is also higher confidence that most precipitation
with the various Gulf systems will be along the coast with lighter
precipitation inland. There are also hints that cold air will be
present, even along the coast. Therefore, snow, especially during
the nighttime hours will be possible. During the day, it will
depend on how hard precipitation falls if snow is maintained as
the main precipitation-type or not. While confidence is low for
snow amounts this far out, there could be some surprisingly
heavier snow amounts given the active pattern. Winter is not quite
through yet.

&&

.AVIATION...

PANC...MVFR conditions will likely prevail this morning as snow
showers pass over the terminal accompanied by 5-10 kt northerly
winds. IFR conditions also cannot be ruled out during heavier
snowfall rates through the morning and afternoon. A low moving
into the Prince William Sound tomorrow afternoon brings light
southeasterly Turnagain Arm winds back into the picture, as well
as more snowfall potential.

-AM

&&


$$