Gale Warning 253, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
434 AM AKDT Sun Mar 31 2024

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

The active pattern for Southcentral continues with satellite and
radar depicting a strong upper level low pressure system pushing
north and east along the Eastern Kenai Peninsula and into Western
PWS this morning as it moves north with a high amplitude longwave
trough centered over western Alaska. On the surface radar and
surface obs support a low pressure system that has effectively
split north of Kodiak Island with a weaken low now moving up Cook
Inlet and the stronger surface low continuing to track northeast
into PWS. This combination of upper level support and surface low
pressure systems continues to bring strong winds and precipitation
over much of South Central Alaska.

Ahead of the front, very strong winds have been observed last
night and this morning along Turnagain Arm, the Anchorage Hillside
and Palmer. Several bouy's in the Gulf of Alaska have recored
hurricane force wind gusts as this powerful system moved north
this morning. A strong surge of colder air with a rapid transition
from rain or rain and snow mix to all snow along with winds
gusting 40 to 60 mph has been noted as the front pushes north
through Cook Inlet this morning. Bands of wet and heavy snow
behind the front combined with strong winds will produce low
visibility at times this morning along the Western Kenai
Peninsula, Anchorage and the Mat-Su Valley with 1 to 3 inches of
snow expected. The heaviest snowfall will be along the front Range
of the Chugach, the Anchorage Hillside and north and east of
Palmer especially in Hatcher Pass. A High Wind Warning remains in
effect this late morning for Anchorage where the strong southerly
winds with gusts to 60 mph will continue into late morning. The
high winds combined with heavy snow showers will reduce visibility
at times in the Western Kenai, the Anchorage Bowl and Mat-Su
Valley.

The low moving north along the Eastern Kenai Peninsula continues
to bring snow and a rain snow mix at seal level and heavy snow to
Thompson Pass. Winter Weather Advisories remain in effect for
these areas through this late this morning for Eastern Kenai
Peninsula and Western Prince William Sound while snow will
continue into this afternoon with Winter Weather Advisories
continuing into the afternoon for the Susitna Valley north of
Talkeetna, Thompson Pass, as well as the Copper River Basin from
Tonsina south.

Another low moves northeast out of the upper level trough over
western Alaska into the Northwest Gulf of Alaska on a similar
track on Monday with another round of precipitation and strong
winds expected Monday and Monday night and again mid week as a
strong front wrapping around a low in the Bering Sea will likely
be the focal point for a weak low or trough to develop in the
northwest Gulf of Alaska.

-CC

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA, the BERING SEA and the
ALEUTIANS (Days 1 through 3)...

A Pacific low has moved inland and cyclonic flow will continue
over Southwest Alaska and the eastern Bering. The radars at King
Salmon and Bethel still have light precipitation on them early
this morning and models suggest more snow is expected which
justified extending the winter weather advisories for zone 161
(including Dillingham), zone 155 (which includes Nunivak Island
and the Kuskokwim Delta) and zone 152 (the Lower Kuskokwim
Valley). An Arctic trough will push into SWAK and temperatures
will plummet. By Monday morning low temperatures will get down to
the negative single digits for mainland Southwest while the AKPEN
sees mostly teens with singles digits for the northern AKPEN.
Further west, another front will push over the Western and Central
Aleutians. This system will just bring light showers and gusty
winds. The global models are pinging into a 953mb-965mb low 00z
Tuesday southwest of the chain. Stay turned for that the updates
on that cyclone.

&&

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

The upper air pattern increases its activity during the next week
as a deep shortwave extending from the Arctic through Interior
Alaska into the North Pacific moves into Canada by late Wednesday.
Most of the energy runs along the Southern portions of Alaska
through the week. A moderate ridge follows right behind and exits
Alaska for Friday. Another shortwave slips into Western Alaska by
the end of the forecast period. Further West, a more moderate
closed low pulls into the Central Bering. Greatest confidence in
the early forecast models is supported by deterministic model
combinations, but becomes more uncertain by the end of the week
between the stronger Western-Central Bering low and multiple
weaker shortwaves rotating across the state.

&&

.AVIATION...

PANC...A mix of VFR and MVFR conditions this morning will persist
with the arrival of a front into PANC this morning which will
introduce wind shear below 2000 ft. Gusty southerly winds up to 50
mph over the terminal to continue this morning. Into the early
afternoon, wind gusts may still reach 40 mph. MVFR conditions
continue today with snow chances during the morning hours. IFR
level visibility are possible with periods of heavier snow showers
this morning.

&&