Gale Warning 757, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
518 PM AKDT Fri Nov 1 2024

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

Conditions across Southcentral have improved substantially since
Thursday and early this morning for most locations, with snow
tapering off from the Western Kenai Peninsula up into the Mat-Su
Valleys. Generally drier weather is forecast from the Anchorage
Bowl into the Copper River Basin through the weekend while the
next incoming area of low pressure remains well south of the Gulf
Coast. In contrast to interior locations of Southcentral, coastal
areas will continue to see precipitation chances as southeast flow
pushes Gulf moisture into the eastern mountain faces, with
periods of continuous rain expected for Prince William Sound and
the Eastern Kenai Peninsula. Forecast models are indicating the
next round of potential precipitation for interior Southcentral
will arrive late Sunday into early Monday morning of next week.
While model agreement could be better, the good news is that,
regardless of preferred model solution, the next system appears to
be much weaker in comparison, with only 1 to 2 inches of snow
currently forecast to reach Anchorage.

If we take a look at afternoon satellite imagery a ~960 mb low is
tracking just south of the Alaska Peninsula this afternoon with a
gale force front currently lifting into Kodiak Island. ASCAT
passes reveal easterly to southeasterly gales along the front
with storm force winds approximately 115 nm S of the low's center.
The low is expected to move immediately southeast of Kodiak
Island through tonight with gales overspreading much of Kodiak
Island into early Saturday morning. There is some potential for
gusts closer to 50 knots through the bays and passes. Warm
southeast flow will keep any precipitation associated with the
front as all rain.

The low then continues northeastward through Saturday, eventually
becoming more stationary roughly 90 nm SE of Canoe Island late
Saturday evening. In the short term gusts to 50+ knots are
forecast through the Shelikof Strait and across the Barren Islands
through midnight tonight. Expect seas of 8 to 12 feet before
conditions diminish late tomorrow morning. With the low's eastward
movement on Saturday, the area of previously mentioned storm
force winds on the south side of the low will also expand
eastward, potentially resulting in 40 foot seas across the
offshore zone of 352.

BL

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 and 2: Today through Monday)...

A storm force low is currently passing just south of the Eastern
Aleutian Islands and the Alaska Peninsula. Gusty winds of 60 to
65 mph are impacting the Central and Eastern Aleutian Islands and
will continue until the low moves into the Gulf of Alaska on
Saturday. Moderate to heavy rainfall is also impacting these
locations as the low tracks east. Lingering small craft gap winds
will affect the Alaska Peninsula until Saturday evening. A small
low will bring localized small craft winds and rain to the western
Aleutian Islands. This small low will slowly move northeast and
will dissipate by Sunday.

Cold air advection will arrive in Southwestern Alaska behind
today's low. This will interact with lingering moisture in Bristol Bay
and the Kuskokwim Delta regions to allow for snowfall to develop
on Saturday. The south part of Bristol Bay will see either rain
mixed with snow or just rain. No freezing rain is expected due to
the colder air aloft. Snow accumulations through Sunday morning will
vary but will range from 2 to 5 inches with the greatest
accumulations occurring north of Dillingham.

Sunday will be relatively calm with a few shortwaves crossing the
Bering Sea. These shortwaves allow for 10-20mph winds and
rainfall to affect most of the Bering. The next weather event will
be a strong low that will sweep into the Bering by Monday
afternoon. This low is associated with the remnants of Typhoon
Kong-rey and will bring storm force winds and heavy rainfall as it
passes through the Central Aleutians. There is uncertainty on the
track of this low, but ensembles are hinting that it will take a
northeasterly track through the Bering Sea. Despite strong warm
air advection traveling with the low, the Aleutians and Alaska
Peninsula could see some mixed precipitation ahead of the low due
to the cold air mass that the low is moving into.

-JR

&&

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

Weather across Alaska continues an active pattern as a series of
strong lows and fronts work their way over the state through the
forecast period. A broad upper level low extends across the Bering
into Western Alaska, with the most active weather over Southern
Alaska. An ECMWF / GFS combination maintains good continuity in
the strengths and paths of the transitory systems. The first of
these lows is the remnants of the former tropical system Kong- Rey
crossing the Aleutians into Bristol Bay on Tuesday before
recurving over Southwest Alaska through Thursday. As the central
surface pressures remain around 950 mb, this system brings
widespread heavy rains from the Central Aleutians and Alaska
Peninsula into Southwest Alaska by Thursday. Gale force winds over
the Central and Eastern Bering begin to diminish late Tuesday,
with some coastal flooding possible through Wednesday. High end
gales remain over the Southern flank of the storm, affecting
Kodiak Island and the Southern end of the Kenai Peninsula, Barren
Island and Kamishak Bay before dropping off Wednesday. Storm focus
changes to Western Alaska after midweek, as winds diminish, but
rains continue to spread towards Nunivak Island through the week.
Heavier rains spread across Southcentral Alaska from the Eastern
slopes of the Alaska Range all the way to the Canadian border
through Friday. Beginning midweek, another well developed North
Pacific low and front slips Eastward just South of the Aleutians
before turning into the Western Gulf for Friday. This brings
another round of heavy rains and gusty winds along the AKPEN and
into Kodiak Island and Southcentral Alaska.

&&

.AVIATION...

PANC...IFR ceilings will linger this afternoon into early
evening. A front moving in from the southwest may help increase
vertical mixing and therefore lift some of the lower clouds to
MVFR overnight. This front may also lead to LLWS development this
evening through early Saturday morning.

&&

Preliminary Local Storm Report
National Weather Service Anchorage AK
1036 PM AKDT Fri Nov 1 2024

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

0300 PM     Snow             1 W Anchorage (Potter V 61.05N 149.78W
11/01/2024  M5.0 Inch        Anchorage          AK   Public

            0.38 SWE.

&&