937
FXAK68 PAFC 091430
AFDAFC

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
530 AM AKST Sat Nov 9 2024

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

The low in the Gulf of Alaska that has brought unsettled weather to
the northern Gulf waters and coastal communities over the last few
days continues to weaken, with latest surface analysis showing the
pressure dropping to 996mb as of this writing. Shower activity
associated with the low continues to push onshore along much of the
Gulf of Alaska Coast from Cordova to portions of the eastern Kenai
Peninsula. Observations note precipitation hasn`t been able to
penetrate as far east overnight, largely remaining to the east of
the Seward Highway and away from the passes. Still, wouldn`t rule
out a few showers making it to Turnagain Pass or Summit Lake this
morning as the low drifts north, dissipating as it does so. Near-
surface temperatures along the road system are once again just
marginally conducive for snow, so thinking any accumulation will be
minimal this morning should snow fall.

VIIRS Nighttime Microphysics imagery shows a largely clear sky
across a significant portion of the Copper River Basin eastwards
to the eastern Susitna Valley, with partly cloudy to broken skies
south and west. The clear skies over the Copper Basin have allowed
temperatures at various sheltered/valley sites to occasionally
drop to near or below 0 early this morning thanks to excellent
radiational cooling. The only instance of fog development really
showing itself at this time on satellite is the area along the
Glenn near Eureka, confirmed by PAZK ob recording FZFG at 1/2 mi
vis.

As we progress into the day, mostly quiet weather for southcentral
will prevail. The aforementioned northern Gulf low will dissipate as
it attempts to drift north, with a ridge axis extending out of Yukon
and through the Copper Basin and Susitna Valley that will yield
mostly sunny skies w/ seasonable temperatures.

The next low pressure system will be quick on the heels of the
departing low. A large upper-level low quickly moving on the south
side of the AK Peninsula, with multiple vort centers readily
visible on satellite imagery, will enter the Gulf of Alaska later
today. Models have been trended a smidge deeper/stronger with
this low as it moves south of Kodiak Island, with several of the
latest model runs suggesting it deepening to the mid 960s. The
result of the stronger model runs manifests itself in the forecast
wind field, where we`ve increased wind speeds across the Gulf of
Alaska to Storm Force (>48kts) for Saturday night into Sunday
morning. The biggest land impact will be that of Kodiak Island
once again where 1-2 inches of rainfall and strong easterly winds
will impact Kodiak City and the nearby area. Elsewhere, consensus
remains strong that precipitation will remain confined to the Gulf
coast, with some light precipitation getting into the Seward
Highway portion of the Kenai Peninsula again.

The low will progress southward on Sunday, with wind speeds
abating and precipitation gradually diminishing through the day
for the Gulf and Kodiak Island. By Monday, quiet weather will
prevail again for just about the entirety of southcentral Alaska.
A low-amplitude shortwave trough lifting from Southwest Alaska
towards Southcentral and then Yukon may generate some light
snowfall for Paxson and perhaps Mentasta Lake, though accumulation
is expected to be light at most.

-Brown

&&


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

Windy and wet as a North Pacific low skirts south of the Alaska
Peninsula tonight. The Central and Western Aleutians will continue
to see unsettled weather as two more storm systems approach. For
the remainder of Southwest Alaska and the Eastern Aleutians,
expect quieter and colder weather for Sunday and Monday. No major
hazards are anticipated, though gusts as high as 50-60 mph are
forecast for the Eastern Aleutians and Alaska Peninsula from this
afternoon through tomorrow morning in the wake of the departing
low.

Diving into the details... few major changes from the previous
forecast, though a minor southward shift in the track of a low
currently south of the Alaska Peninsula has led to updates in
winds and precipitation totals. One surprise this morning has been
the development of a fog bank across parts of Bristol Bay
(including Dillingham, New Stuyahok, and Igiugig) due to calm
winds, clear skies, and a low-level inversion. Area weather
stations show light snow precipitating out of this fog bank, but
expect any accumulations to be minimal.

For Southwest Alaska and the Eastern Aleutians, expect winds to
peak this afternoon through tomorrow morning, then gradually
decline through the remainder of Sunday. As the low departs and a
ridge builds in, much calmer weather will be in store for this
area. Northerly flow ahead of the ridge axis will help usher in
cooler air, dropping overnight minimum temperatures into above-
zero single digits and teens from about Naknek north. Areas south
(and the Pribilof Islands) will see low temperatures ranging from
the low 20s through high 30s. With drier air moving in, clearer
skies are also expected.

For the Central and Western Aleutians, expect a continuation of
unsettled weather. The weather looks to be pretty benign through
early Monday morning as a North Pacific low tracks several hundred
miles south of the Aleutians. This track will bring the low near
enough to influence weather (including bringing some light
rain/snow mix) but far enough south that winds are not
anticipated to be stronger than small craft speed. However, this
could change if the track of the low changes. By Monday, a
Kamchatka low pushes its front across the Western and Central
Aleutians, bringing winds to gale force and moderate to heavy
rain.

-Chen

&&


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

Starting Tuesday the low over the Gulf will continue to exit to
the south and ridging will build into most of the state. This
quiet weather will continue across southcentral through the week.
This prevailing high pressure system will bring cooler
temperatures to much of the state into the upcoming week.

Later in the week, a strong area of low pressure is expected to
develop in the North Pacific and cross into the Bering, reaching
the west coast of Alaska by late in the week. This system could
bring some gale-force wind gusts to the west, possibly around the
Kuskokwim Delta at this time. The models have not been consistent
with the placement of this low and attention will be needed to
monitor how this system progresses in the coming days.

-MB

&&.AVIATION...

PANC...VFR conditions and light northerly winds will persist, with
occasional gusts up to 15 kts through Sunday morning.

&&


$$