Big Lake, Alaska 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

658
FXAK68 PAFC 090629
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
1029 PM AKDT Tue Apr 8 2025

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

A trough will continue to dig into the Gulf of Alaska the next 72
hours resulting in a continued series of lows moving through
Southcentral and Prince William Sound. Precipitation will range
from rain to snow during this time.

A low in the Gulf of Alaska moved onshore and through the Kenai
Peninsula today. Southeast winds through coastal areas of Prince
William Sound kept precipitation as rain from Cordova to Valdez.
Persistent easterly winds and low level pooling of cold air resulted
in a heavy and wet snowfall for Whittier and Portage into late
this afternoon. A changeover to a mix of rain and snow showers
briefly occurred earlier this afternoon keeping snow accumultions
below yesterday`s totals. At higher elevations of the Chugach and
at Thompson Pass, the precipitation remained as snow with 8 to 12
inches of new snow by 4:00pm. The steady snow will taper off this
evening to light snow.

As the low continues to move over the the Kenai Peninsula
overnight, pushed westward by weak ridging over the Anchorage Bowl
and Mat- Su Valley, it will continue to bring accumulating
snowfall to Western Kenai. Tomorrow morning, a period of
southwesterly winds into the Homer / Kachemak Bay will result in
a brief period of increased snowfall intensity for Homer and the
Homer Bluffs leading to an additional snowfall accumulation of 3
to 6 inches. A Winter Weather Advisory has been issued for SW
Kenai Peninsula and Southern Kachemak Bay through 1:00 pm
tomorrow. In Seward north to MOose Pass, northelry winds will
remain through early tomorrow morning causing continued
accumulating snowfall.

-DJ


&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: This afternoon through Friday afternoon)...

Unsettled and lower impact weather is forecast through the next 3
days as weaker systems move across or linger on the periphery of
the Bering Sea. The most impactful weather will persist through
tonight, as a robust upper level low, cold air advection, and a
tight surface pressure gradient are contributing to gusty winds
along the Alaska Peninsula. The strongest gusts in the past 12
hours have been observed at King Cove Airport, where winds
channeling through the terrain have led to gusts up to 66 mph.
We`ll continue to closely monitor conditions at King Cove, where
gusty winds in combination with snow showers have led to
visibilities as low as one-quarter to one-half mile at times.
While conditions seem to have improved with showers beginning to
taper off, it`s possible that visibilities may once again drop
below 1 mile through tonight.

By tomorrow morning, conditions will gradually improve as the low
exits into the Gulf and weakens. For Wednesday, the main focus
will be on a fairly weak low that moves across the Eastern Bering
Sea and Pribilof Islands towards the Alaska Peninsula. This low
will bring another round of light snow to the Pribilof Islands,
Eastern Aleutians, and Alaska Peninsula, with the potential for
rain to mix with snow as temperatures rise above freezing in the
afternoon. Parts of Nunivak Island, Kuskokwim Delta, and Kuskokwim
Valley will likely also see some light snow as a weak upper level
shortwave moves through. Otherwise, expect clearer skies, lighter
winds, and cool temperatures for Southwest Alaska.

By Thursday, forecast confidence diminishes as a shortwave trough
dives into the Bering Sea from Russia. There`s uncertainty with
how this trough will interact with an upper low near the Seward
Peninsula and, therefore, the positioning of the resultant surface
low. The overall impact of this uncertainty is fairly small,
mostly affecting the forecast for the Northern to Central Bering
Sea, Pribilof Islands, and Kuskokwim Delta. As of the writing of
this discussion, the latest model runs have trended the surface
low closer to Saint Matthew Island, suggesting quieter weather for
Kuskokwim Delta.

Further south, a North Pacific low and its front slowly edge
towards the Aleutian Islands by Friday, gradually pushing out the
ridge of high pressure that sits across the Western and Central
Aleutians through Thursday. There are some positional differences
with this low pressure system, which will affect forecast winds
and precipitation chances along the Aleutian Chain.

-Chen

&&


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

A well developed closed upper low over the Northern Bering begins
its sweep across the Alaska Peninsula into the Gulf of Alaska and
Eastern North Pacific by Tuesday. This center runs through an
elongated negatively tilted trough and slowly weakens through the
period. It is also dragging considerable colder air with it. Throw
in a number of shortwaves passing over the Aleutians and
generally unstable conditions will be spreading from the Central
Bering across Southwest Alaska. A generalized blend of forecast
models covers the larger scale features, but uncertainty remains
high in the unsettled pattern and smaller details.

A developing surface low to the South of the AKPEN spread areas
of moderate snow and gusty winds from the Eastern Aleutians and
AKPEN into the Central Bering on Saturday. The snow will change to
moderate rain over the AKPEN and Bristol Bay, spreading over
Kodiak Island and along the Southcentral coastal zones as the low
gets stronger across Bristol Bay. Winds increase to gale force
late Saturday over the Eastern Bering, and through the Barren
Islands into Kamishak Bay late Saturday and extend along the
Southcentral Coast through Sunday. A weak surface and front push
across the Western Aleutians Sunday. Locally moderate snow extends
along the West Coast and over the Eastern Bering. As this surface
low slips back across the AKPEN, mostly snow remains and slowly
dissipates in the West by Tuesday. Moderate to heavy rains move
from Kodiak Island into the Eastern Kenai Peninsula, and Western
Prince William Sound, diminishing Tuesday.

- Kutz

&&

.AVIATION...

PANC...Expect mainly MVFR conditions and light northerly winds
through the afternoon hours as light snow develops over the
terminal. IFR of LIFR conditions cannot be ruled out at times
this evening as the band of snow moves through, by around 03z.
Southeasterly Turnagain Arm winds will develop overnight into
early Wednesday morning. Bands of snow showers will likely develop
as these winds increase and colder air moves in. There is still
uncertainty in the exact placement of these snow bands; however,
any snow that does develop over the terminal early Wednesday
morning could be heavy and reduce cigs and vis back to LIFR for a
time. Again, forecast snowfall amounts are less certain but
consensus in guidance suggests another 1 to 3 inches possible
through Wednesday morning.

-TM

&&
$$