Gale Warning 215, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
537 AM AKST Sun Feb 25 2024

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

A compact surface low and upper-level short wave continue to move
southeast into the eastern Gulf this morning. Strong cold air
advection in the wake of both features is allowing gusty
northerly gap winds to continue along the Southcentral coast this
morning. Gusts to 40+ mph are possible from Seward to Whittier
and Thompson Pass through Sunday. With the recent snowfall, this
wind will likely produce areas of blowing snow during this time,
with these areas likely to see significantly reduced visibilities
at times.

Following this system a weak ridge will build ahead of a robust
upper level low over southwest Alaska. The associated parent low
in Bristol Bay will push its front over Kodiak Island into the
western Gulf Sunday night into Monday. With warm air advection
along the front, precipitation will likely change from snow to
rain quickly for much of southern Kodiak Island. For Kodiak City,
several hours of snow and gusty easterly winds are likely Monday
morning before temperatures climb into the lower to mid 30s,
allowing for a rain/snow mix and likely changeover to all rain. 1
to 3 inches of snow is possible for Kodiak City before a
changeover to rain.

Models remain in good agreement on a triple point low developing
near Kodiak and the Barren Islands Monday afternoon, but diverge
in its track thereafter. The exact track of this low and its
associated front will likely determine the inland extend of
snow along the Southcentral coast through Tuesday afternoon. The
position, strength, and track of the low will also determine
precipitation type and potential for blowing snow in northern
Kodiak for late Monday into early Tuesday morning and the
potential for snow and blowing snow for Homer and along the
Sterling Highway south of Kenai. Regardless, areas of moderate
snow are expected to make a return to much of the immediate
Southcentral coast Monday afternoon through Monday night. Gusty
winds are also expected to return to the Mat Valley Monday morning
into Tuesday afternoon as the flow turns northeasterly as the
triple point low develops.

Northerly gap winds along the coast along with a reinforcing shot
of colder air will return to Southcentral late Tuesday through
the end of the as this system moves southeast and exits the
region.

-TM/ME

&&

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

Mid to upper level ridging is promoting drier conditions across
the eastern Bering and Southwest Alaska. Most of the Kuskokwim
Delta and Lower Kuskokwim Valley are seeing overcast skies this
morning while the Greater Bristol Bay remains mostly clear. Cloud
cover will increase from the west across all of Southwest today as
a Bering system approaches. The low is currently centered over
the western Aleutians as its front lifts across the Bering and
eastern Aleutians. The front will pass over the Pribilof Islands
today, bringing periods of heavy snow and southeasterly winds
gusting up to 45 mph at times. Gusty winds combined with heavy
snowfall may reduce visibility down to one mile or less at times.
The worst conditions will likely last a few hours this afternoon
into the evening. This system is expected to bring 3-5 inches of
new snowfall to the Pribilofs today. Low visibilities should start
to recover late this evening as the front passes, precipitation
lightens, winds diminish, and temperatures raise near freezing.

By Monday morning, the low center will track over the Pribilofs
and its front will reach the Southwest coast. Deteriorating
conditions across Southwest Alaska will begin Sunday night and
continue into the beginning of the week. Moderate to heavy snow is
forecast for the Greater Bristol Bay area along with winds
gusting as high as 45 mph in some locations. This will result in a
threat for blowing snow and reduced visibility down to one half
mile in addition to total snow accumulations of 5 to 10 inches. A
Winter Weather Advisory is in effect for Bristol Bay from Sunday
night through noon Monday. A second Winter Weather Advisory is in
effect for the Kuskokwim Delta Coast from Sunday night into Monday
afternoon. Lesser snow accumulations of 4 to 7 inches will occur
coincident with northeasterly winds gusting from 30 to 45 mph.
Snow and blowing snow, with visibility reduced to one half mile,
is anticipated along the Kuskokwim Delta Coast from Kwigillingok
up into Toksook Bay and Mekoryuk. A third Winter Weather Advisory
for snow across the Lower Kuskokwim Valley will be in effect early
Monday morning through Monday evening. Highest snowfall totals of
6-8 inches are expected for Stony River and Sleetmute, with
decreasing amounts of 4-6 inches west towards and including
Aniak. The heaviest snowfall is expected Monday morning. Overall,
conditions become less across the domain on Tuesday as the
aforementioned system exits and another system approaches the
western Aleutians.

-AF/BL

&&

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

The mid to long range forecast looks to remain rather unsettled from
early to midweek with broad occluded low moving inland near Bristol
Bay and a more compact Kamchatka low that will begin to move into
the western Bering. A new triple-point low will develop near the
southern end of the Kenai Peninsula as the associated frontal
boundary lifts up across the Gulf. Models have this low rapidly
deepening before tracking it up the eastern side of the Kenai.
Strong gap flow winds will develop along the eastern Kenai and
Chugach Mountains in response. Easterly storm force winds also look
to develop along the northern Gulf coastal areas as pressure
gradient tightens along the the coastal mountains allowing barrier
jet to develop. Models and ensemble consensus also hint at modest
ridging building into the Bering by late in the week. The upcoming
week will also feature much colder temperatures as upper jet shifts
south and cold northerly flow dominates much of the Alaska mainland
and central Aleutians.

- PP

&&

.AVIATION...

PANC...Fog in the vicinity could move over the airport for a
brief period through Sunday morning. Otherwise, VFR conditions and
light winds are expected.

rux

&&