Gale Warning 877, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
508 AM AKST Mon Dec 16 2024

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

The upper level low that brought mixed precipitation to the Cook
Inlet areas and Mat-Su, and snow to the eastern Sound and Copper
Basin will lift north today as a sharp high pressure ridge builds
in from the Panhandle. This will lead to quiet weather for the
vast majority of the region as the high prevents moisture from
streaming north and keeps the storm track to the south and west.
For today, expect seasonal temperatures with light precip
lingering over the eastern Sound and western Susitna Valley,
though this will taper off throughout the day. By tomorrow, a
steady light to moderate rain will set up over Kodiak Island,
where it will persist through at least Wednesday as easterly flow
is enhanced by a series of systems moving south of the Island and
into the Bering Sea. For the mainland, light rain and snow will
linger for the southern Kenai Peninsula, making it north to
Whittier at times. With little to no upper level forcing,
precipitation will be very light and confined to the coast. For
the rest of the region, expected mild temperatures and a mixture
of sun and clouds over the coming days.

&&

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

A weakening low pressure system in the Bering Sea will generally
moderate conditions in Western Alaska in the coming days. Before
this occurs, a shortwave trough lifting northward this morning is
expected to bring light snow and easterly winds with gusts to 35
mph to the Kuskokwim Delta. Precipitation then dries out across
much of Southwest Alaska by this afternoon. Energy gets
transferred to a new system as a wave moving through the bottom of
the parent Bering low reforms its own center over the Central
Aleutians on Tuesday. This orientation will bring southeasterly
flow to Southwest Alaska, raising temperatures and allowing for
downsloping to keep the region mostly dry on Tuesday and
Wednesday. The southeastern side of the Alaska Peninsula however,
could see heavy precipitation with 2-4 inches of rain possible
from this morning through tomorrow morning.

As for the Aleutians/Bering Sea, expect generally gusty winds and
rain showers through the week. As our aforementioned parent
Bering low weakens, the gale-force winds that are currently
widespread will continue to decrease in coverage. A series of
compact surface lows rotating up into the Bering will locally
enhance winds and precipitation as they cross the Aleutians on
Tuesday and Wednesday. Models are beginning to come into better
agreement with the timing and location of these, giving the
Eastern Aleutians possible gale to storm-force gusts Tuesday night
before easing off Wednesday and Thursday.

&&

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

A trough spanning the Aleutian Chain to south of the Gulf of
Alaska maintains unsettled conditions with warm southeasterly
flow up from Gulf of Alaska, across the interior, and southwest
through the Bering Sea. This pattern peaks Saturday afternoon
with slightly above average temperatures through the weekend.
Terrain enhanced rain at low elevations and mountain snows are
possible for coastal regions, while downsloping should keep lee-
side locations drier. Unsettled weather will persist through the
weekend, transitioning from southeasterly to northeasterly flow
across the Bering Sea and Aleutians.

It is increasingly likely one or more shortwave features from the
North Pacific will enhance winds and precipitation for the Gulf
Coast Thursday into Friday and again on Sunday. There are hints of
especially strong easterly winds from Kodiak Island up to the
southern Kenai Peninsula, although this will depend on where the
smaller scale features set up. A shortwave track south of Kodiak
Island would signal stronger winds for Kodiak than a track to the
east of the Island.

&&

.AVIATION...

PANC...Expect light north winds and VFR conditions through the TAF
package. A few clouds could form below 1000 ft later this morning
and afternoon, but ceilings will remain above 5000 ft through the
package.

&&