Small Craft Advisory 9, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
509 PM AKST Tue Jan 2 2024

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

The dominant feature across the region is a large 940 mb low just
south of the central Aleutians this afternoon will cross into the
Bering Sea overnight into Wednesday morning. This low will linger
for most of the remainder of the week in the eastern Bering Sea
before dissipating on Friday. This pattern will maintain mild,
southeasterly flow moving into Southcentral Alaska.

A strong front associated with this Aleutian low will move across
Kodiak tonight and then weaken some as it moves to the north Gulf
coast Wednesday. There will be a mix of rain and snow with this
front for the Kenai Peninsula and north Gulf coast on Wednesday.
Upslope areas on the windward side of the mountains will see the
vast majority of the precipitation with less for inland areas on
the lee side of the mountains. By Wednesday night, colder air
aloft will trickle into the area due to the occluding low and
should begin to shift the dominant precipitation type back to snow
for most of the area. Light and scattered showers may linger into
Thursday.

&&

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

The forecast is remains on track with a large, strong, deep low
slowly moving north towards the Aleutian Chain. The low bottomed
out around 937 mb late this morning and early this afternoon. The
front attached to this behemoth moved over the Central and
Eastern Aleutians this morning, and the wrap around front
continues to approach the Central Aleutians this afternoon. The
front out ahead of the low continues to tracks up the Alaska
Peninsula towards the Southwest coast this afternoon and evening.
Storm force winds and high end gales are impacting the the
Aleutians currently. The Winter Storm Warning for the area has
been allow to expire as mostly locations have turned to rain or a
rain snow mixture. Winds for this area will come down below storm
force, but will remain in higher end gales.

A High Wind Warning is in effect for Interior Bristol Bay, including
Iliamna, Koliganek, and New Stuyahok. Most locations will not
experience warning level winds, however, wind gusts reaching 60
mph are possible, namely along the Alaska Peninsula south of King
Salmon, as well as along the higher elevations. BUT! Areas
particularly vulnerable to the strong easterly winds racing out of
Kamishak Gap may see warning criteria wind gusts to 75 mph, this
includes Iliamna, Koliganek, and New Stuyahok.

Along the coast, a Blizzard Warning has been issued for the
Kuskokwim Delta coast and Nunivak Island tonight. Wind gusts to 50
mph are possible and areas of blowing snow will bring
visibilities down to a quarter mile at times with snow
accumulations between 1 to 3 inches possible.

The Pribilof's continue to see high end winds with gusts to 55
mph continuing into this evening. Winds switch to northeasterly
overnight and will begin to weaken.

This low pressure system lumbers into the southeast Bering Sea and
slowly weakens into Friday.

&&

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

Active weather continues for the long-term forecast, with high
confidence that yet another strong low will move into the Bering
Sea on Friday. Model agreement is about typical for this
timeframe. We continue to monitor the following hazards for this
strong and moist system:

* High Winds: Western and Central Aleutians, Saturday Jan 6
* Heavy Precipitation: Eastern Kenai Peninsula and Prince William Sound,
  Saturday Jan 6 through Sunday Jan 7

Of lower confidence are the potential for blowing snow/blizzard
conditions ahead of the low and its front. While strong winds make
blowing snow more favorable, rising temperatures with the arrival
of the front will lead to denser snow and decrease the likelihood
of major reductions in visibility for the Aleutians and Southwest
Alaska. There is also increasing confidence that, based on the
current forecast low track, temperatures will warm enough to
transition snow to rain for the Eastern Aleutians and Alaska
Peninsula. Blowing snow is also a concern for Southcentral;
temperatures should be cooler away from the low center, but winds
will also be weaker. Overall, we'll have a clearer idea once
models come into better agreement on the low track and the timing
of warm air versus precipitation onset.

Cold air wrapping in behind the low should lead to cooler
temperatures across the Bering Sea/Aleutian Islands/Southwest
Alaska for Sunday into Monday. By Monday evening, a North Pacific
low makes its way towards the Bering Sea. There remain some
differences with the track of this low, primarily relating to the
strength of a ridge building in the Gulf of Alaska. A stronger
ridge will keep this low further west, bringing the potential for
fairer weather in Southcentral Alaska.

- KC

&&

.AVIATION...

PANC...VFR conditions and northerly winds will persist. There will
be some gradual lowering of ceilings Wednesday afternoon as a
strong front moves onshore along the north Gulf coast. However,
strong downslope flow and low level dry air will ensure ceilings
remain well into the VFR category.

&&