Gale Warning 771, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
509 PM AKST Tue Dec 26 2023

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

A low pressure system continues to move northward bringing gusty
winds and snow to Cook Inlet, Anchorage Bowl, and the Matanuska
and Susitna Valleys. Snowfall in these areas will range from 1 to
2 inches through the late evening hours. Elsewhere, snowfall will
continue in the Kenai Peninsula with another 1 to 2 inches
expected through later this evening. Wind gusts in the western
Kenai Peninsula will diminish overnight. The evening's snowfall
across all of Southcentral Alaska will remain and light dry
resulting in a greater chance of it blowing around and reducing
visibility. Temperatures tonight will range from the low single
digits to teens below zero in the Copper River Basin to the lower
20s along the coast of the in the Kenai Peninsula and Prince
William Sound. Elsewhere, temperatures will remain steady until
after the snow has ended before dropping into the lower teens to
upper single digits.

A weak ridge of high pressure will build into Southwest Alaska
this evening and signal a continued period of drier weather
through the next few days. High temperatures in the twenties and
teens and lows in the single digits. The exception is the Copper
River Basin where daytime highs will remain below zero and
overnight lows to 20 below zero for the next few days.

A warm storm system could reach the Prince William Sound coastal
areas late Thursday/Friday bringing a chance for rain and
continued warming temperatures.

&&

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

Multiple upper level and surface features will continue to bring
active weather to Bristol Bay over the next 12 to 24 hours. The
main features this evening are an upper level low over the
northern Bering Sea and its attendant surface low over Nunivak
Island.

Overnight, the upper low will consolidate and move over the Gulf
of Anadyr and north across the Chukchi Peninsula. To it's south, a
narrow band of ocean effect snow showers are expected to train
somewhere between Togiak and Dillingham through Wednesday
afternoon. Should these showers linger over any single area,
snowfall rates of 1-2 inches per hour are possible with
accumulations up to one foot.

Over the Bering, cold temperatures will persist with scattered to
numerous snow showers into Wednesday afternoon when a moderate to
strong front reaches the western Aleutians. This feature will
spread across the Bering through Friday, bringing slightly warmer
temperatures and a mix of rain and snow along the occluded front
with gale to storm force winds.

&&

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

The beginning of the long-term period is defined mostly by a
large, complex low pressure system over the central Bering Sea and
a weak trough swinging into the northern Gulf of Alaska. In the
Gulf, the weak trough is expected to enter Prince William Sound
and interior Southcentral Alaska by Friday afternoon/evening. This
will result in likely showers along the coastline with some
moisture pushing into interior Southcentral possible. In the
Bering, the complex low pressure system is suffering from a large
spread in model solutions. This makes tracking where individual
cells, and the progression of the entire system difficult. It does
appear that a frontal boundary will be over the central/eastern
Aleutians and will be advancing eastward, moving into Southwest
Alaska for the weekend. The Pribilof Islands will likely see an
extended period of snowfall from Friday into the next work week.
The remainder of the Aleutian Chain will likely see showers
through the weekend. Details on where low centers establish within
the complex will become more clear as we approach the end of the
week so stay tuned for updates.

&&

.AVIATION...

PANC...Strengthening northerly winds this afternoon ahead of a
low crossing the western Gulf should be enough to dissipate any
remaining fog/stratus in Anchorage and northern Cook Inlet.
Snow showers with the low and upper level short-wave trough
will track up Cook Inlet and the western Kenai into the Anchorage
area late this afternoon. Strong low level southeast flow along
with a fairly dry airmass means snow may not initially reach the
ground. The best chance for snow showers with reduced vis/ceiling
looks to be from around 06Z onward as the southeast flow weakens
and veers around to the south. Any showers that do fall will be
brief in nature, with potential for IFR conditions in showers,
then popping back up to MVFR or VFR.

Forecast confidence drops behind the upper trough late tonight
through Wednesday morning. With a weakened low level inversion,
VFR conditions could prevail. However, radiational cooling and
the remaining inversion could be enough to reform low ceilings.
For now have indicated a MVFR ceiling, though it could be lower.

&&

Preliminary Local Storm Report
National Weather Service Anchorage AK
950 PM AKST Tue Dec 26 2023

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0800 PM     Snow             Seward                  60.11N 149.44W
12/26/2023  E9.0 inch        Kenai Peninsula    AK   Public

            Snow total from the afternoon through 8 PM.

&&

KC