Gale Warning 62, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion...UPDATED
National Weather Service Anchorage AK
Issued by NWS Alaska Aviation Weather Unit Anchorage AK
146 PM AKST Wed Jan 15 2025

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

Today's low pressure system moving across Southcentral is, as
expected, stalling out and weakening over the Kenai Peninsula as
both the upper level trough and surface low weaken as they move
eastward. Satellite imagery shows the tap of moisture feeding
into the front starting around 45N and heading straight into the
the Kenai Peninsula. One item of note with this system is that
the front is stalling a little bit farther south which had put
Homer in the cross-hairs for the snow since around midnight. With
temperatures just above freezing at the Homer airport, it has
been a heavy wet snow accumulating there, but there might be
significantly more on the Homer Bluff with temperatures just a
little colder. There will be more snow the next few hours in
Homer, but it should taper off by mid-morning as the front
finally creeps northward and weakens. There is a diminishing
chance for snowfall in Anchorage today as the aforementioned front
stalls out south of there.

By late this afternoon, this first system will have weakened
significantly and moved eastward as an upper level ridge begins to
build over Southcentral from the southwest. This should bring
clearing skies for tonight and Thursday for inland areas. However,
this ridge will amplify as it moves to the AlCan border in Friday
which will bring in southerly flow aloft and warming temperatures
for Friday and into the weekend.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA AND THE BERING
SEA/ALEUTIANS (Days 1 through 3 - Today through Friday night)...

Main Points:

1) Quick moving ridge arrives over the Alaska Peninsula and
Southwest Alaska.

2) Strong North Pacific Low brings snow, rain and southerly winds
to the Aleutians, Alaska Peninsula, and Southwest Alaska late
this week.

3) Coastal flooding is possible late this week.

The low that brought accumulating snowfall for most of the Alaska
Peninsula and Dillingham area continues to spin through the North
Pacific. Many locations received a trace to a few inches and wind
gusts ranging from 30 to 40 mph by midnight Wednesday. In its
wake, northwesterly winds across Bristol Bay ranging from 20 to 30
mph will bring strong gap winds through the Alaska Peninsula
ranging from 30 to 40 mph. Strong winds are also expected for
Iliamna and Koliganek through late this afternoon as the low moves
across the Kamishak Bay. Today's winds will decrease with the
arrival of a weak ridge. However, this fast moving ridge will be
replaced by an approaching front signaled by strong winds, rain,
snow, and very warm air for the Aleutians, Alaska Peninsula, and
Southwest Alaska.

A strong North Pacific low remains almost stationary south of Adak
through tomorrow morning before heading due north across the
Aleutians into the Bering Sea. Its front sweeping over the Central
Aleutians and Alaska Peninsula tomorrow morning through the
evening hours will result in gale to storm force winds, snow
changing to rain and wind gusts ranging from 50 to 60 mph in gaps
and passes. As the front moves northward, southeast winds could
bring another chance for flooding along the Kuskokwim Delta coast.
Despite the strong push of southwest air north of the Kuskokwim
Delta, cold air currently over the region stays in place through
Friday morning with 850mb temperatures ranging from -8 degrees
Celsius in the afternoon to -2 degrees Celsius in the late morning
hours. Therefore, precipitation from the arriving front beginning
tomorrow evening falls as snow west of Bethel, including Nunivak
Island, through the early Friday morning hours before changing to
a rain/snow mix and eventually all rain Friday afternoon. Wind
gusts in this area tomorrow evening into Friday morning ranging
from 25 mph to 35 mph are also expected, which could lead to
reductions in visibility due to blowing snow. Most models place a
second low in Bristol Bay Friday evening and while the exact
location varies, this would provide a resurgence of warm air and
strong wind gusts for the Alaska Peninsula and Southwest
coastline.

&&

.LONG TERM FORECAST (Days 4 through 7: Thursday through
Sunday)...

Starting Thursday, a high amplitude weather pattern will push in
across the state with upper level ridging extending from the Gulf
of Alaska through the interior and up to the Bering Straight. This
feature will slowly shift eastward through the long term forecast
period being pushed by a broad upper level trough moving from the
Aleutians to the Arctic through the Bering Sea. As the system
traverses northward, gale-force gusts and moderate snow
transitioning to rain are expected for Southwest Alaska from
Thursday through Saturday.

Southerly onshore flow will bring moderately strong wind and
precipitation to the Eastern Aleutians Thursday before progressing
eastward to the Alaska Peninsula on Friday and finally across the
Southcentral coast through the weekend. Shortwaves moving through
the flow will enhance rains along coastal locations, with locally
heavy snow over higher elevations from the Alaska Peninsula to
Prince William Sound. Areas of snow in leeward locations like the
Western Kenai, Anchorage, and Mat-Su are possible at the end of
the forecast period, but downsloping will likely limit significant
accumulation.

A new system from the North Pacific will bring another round of
increased winds and precipitation to the Western and Central
Aleutians beginning Sunday morning.

&&

.AVIATION...

PANC...VFR conditions with ceilings above 5000 ft are likely to
persist through the TAF period. Light northerly winds diminish and
may become variable this afternoon. There continues to be a slight
chance for light snow this afternoon as a band of snow pushes up
Cook Inlet and stalls just south of the terminal as it dissipates.
If there were to be light snow, accumulation would be minimal,
though intermittent MVFR ceilings and visibility would be
possible. The only other concern is a very slight chance for fog
development later tonight into early Thursday, though conditions
appear generally unfavorable for this.

Quesada

&&