Gale Warning 653, NWS Anchorage, AK

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
503 AM AKDT Wed Oct 9 2024

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

A cold upper level low in the Interior of the state has a trough
extending over the Alaska/Aleutian Range and meeting up with a
weak surface low in the Gulf of Alaska. This set up is conducive
for the development of shower activity along the north Gulf coast
and eastern Kenai Peninsula this morning with that activity
spreading northward as the day progresses and into tomorrow.
While that is the big picture, the challenge comes in the details,
and especially precipitation type for tonight into Thursday. With
little temperature advection to bring in colder air, the airmass
may not be cold enough to bring snow down to sea level for
Anchorage and the Matanuska Valley. However, temperatures will be
close and the late night and early morning hours could cool things
enough to mix some snow in with rain showers for these areas.
At this time, we are looking for snow levels to be in the 500 to
1000 ft range along the Kenai and Chugach Mountains. This means
that any precipitation overnight for areas from around Hillside
drive or higher in Anchorage should see snow. Turnagain Pass is
also likely to see some snow with these showers, and maybe even
during the day today. Chickaloon Pass may also see snow tonight
into Thursday morning. Amounts in any of these places are not
expected to be very high, but it may be the first snowfall of the
season for a number of areas, especially ones with just a little
bit of elevation.

The upper level trough moves through Southcentral and into the
Copper River Basin Thursday. This could bring in some snow showers
to the Copper Basin with it, but it is looking doubtful that
enough moisture will make it across the mountains to do much.

The next system is a very strong one that will move quickly
through the Bering Sea and send a strong front into the
southwestern Gulf Thursday night and the rest of the Gulf through
Friday. This will hit Kodiak especially hard with strong winds
and heavy rain on Friday. There is the possibility for Hurricane
Force winds along the north Gulf coast depending on the strength
of the barrier jet that sets up with this front on Friday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA AND THE BERING
SEA/ALEUTIANS (Today Through Saturday morning)...

A weak frontal system continues pushing inland of the Kuskokwim
Delta and Bristol Bay this morning. The greatest moisture
associated with this system is over the Kuskokwim Delta this
morning where interior places like Bethel look to see their first
snow flakes of the season this morning. Little to no accumulation
is expected. Farther south, moisture and lift are weaker across
Bristol Bay, although places like Togiak and Dillingham could
still see a few flurries this morning. As temperatures warm
through the day, any precipitation should turn to rain by late
morning.

This system will fizzle out over the southwestern mainland
through the afternoon and evening. Our attention then turns to the
west where a low pressure looks to enter and strengthen in the
western Bering Sea today. The western Aleutians will feel the
first signs of the system this morning with light rain moving in.
As the day goes on, winds look to pick up to 34 to 45 mph and seas
look to build to around 15 ft. The storm will continue to move
eastward to just southwest of the Pribilof Islands by Thursday as
it deepens. The main core of strong winds will continue to be to
west on the backside of the storm as cold air wraps into it from
Russia. Another aiding factor in the strong winds is an amplifying
ridge building over Kamchatka which helps to enhance the northerly
cold air advection from Russia. Sustained winds across the western
and central Aleutians look to be in the strong gale-force
category, while marine zones around those areas could experience
sustained storm-force winds.

The system then looks to moves southeastward to near the eastern
Aleutians and southern Alaska Peninsula (AKPEN) by Thursday
evening. Energy will then transfer from the Bering Sea over the
AKPEN into the North Pacific as triple point occurs Thursday night
and early Friday morning. The storm then looks to meander around
the southern AKPEN through Friday while continuing to strengthen.
A reinforcing shot of cold air looks to once again drop southward
out of Russia and into the western and central Bering for Friday.
With the amplified ridge remaining across Kamchatka and the strong
low just south the AKPEN, the dynamics are favorable for a long
duration wind event, similar to the October 3rd-4th strong low,
over the eastern Aleutians, and perhaps the southern AKPEN.
Synoptic winds also look to be strong through Kamishak Gap and
into Bristol Friday into Saturday. In general, wind gusts from 50
to 75 mph area possible for Bristol Bay, the southern AKPEN, and
the eastern Aleutians Friday. The system drops further south into
the North Pacific for Saturday as strong gusty winds persist
across the eastern Aleutians due to the persistent amplified
Kamchatka ridge and good cold air advection from Russia and the
Arctic.

&&

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

A large storm-force low centered south of the Alaska Peninsula on
Saturday will dominate the weather pattern across southern Alaska
through next week. The large low will have a broad wind field,
with a storm force front (and potential hurricane-force gusts)
lifting across the north Gulf coast on Saturday while cold,
Arctic air streaming south across the Bering Sea leads to a large
area of gale and storm force winds blowing across the Pribilofs,
central and eastern Aleutians, and Alaska Peninsula. While the
front in the Gulf lifts quickly north and weakens rapidly as it
pushes inland over Southcentral Alaska, gusty winds in the Bering
Sea will diminish much more slowly as Arctic air continues to
surge southward through Monday. High seas can be anticipated in
association with this low, likely up to 25 feet particularly in
the area between the Pribilof Islands and the eastern Aleutians
for much of the day Saturday and along the front in the Gulf
Saturday morning before it moves inland.

A band of precipitation also lifts across southern mainland
Alaska on Saturday along with the front, primarily falling as rain
as the low draws warm, moist air up from the subtropical Pacific.
The heaviest rain falls along the coastline, focusing along the
eastern Kenai Peninsula, especially on Saturday. After the front
lifts into the Interior, precipitation will mainly focus along the
coast of the Gulf of Alaska and the north side of the Alaska
Peninsula and eastern Aleutians in the form of upslope shower
activity. Arctic air streaming southward will contribute to
unstable conditions that also produce bands of showers across the
eastern Bering Sea through Monday.

Along the far western portions of the domain, the extratropical
remnants of what is currently Tropical Depression 21W in the
western Pacific have the potential to bring gale force winds
through the western Aleutians beginning Sunday. This low tracks
south of the Aleutians, bringing a band of light to moderate rain
as far as the eastern Aleutians by Tuesday, though winds likely
weaken below gale force east of Kiska. This low has some
potential (low, <30% chance) to strengthen as it tracks toward
the Gulf of Alaska later in the week.

&&

.AVIATION...

PANC...VFR conditions persist with 10 to 15 kt winds during the
day. Ceilings may descend into the MVFR range Wednesday night to
Thursday morning as chances increase for periods of light rain and
snow.

&&

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
352 PM AKDT Wed Oct 9 2024

AKZ121-101400-
Western Kenai Peninsula-
Including the cities of Kenai, Soldotna, Homer,
and Cooper Landing
352 PM AKDT Wed Oct 9 2024

...STRONG AND GUSTY WINDS FRIDAY FOR COASTAL COMMUNITIES ALONG
THE WESTERN KENAI PENINSULA COAST AND KACHEMAK BAY...

Strong northeasterly winds will develop across Cook Inlet and
Kachemak Bay Friday morning through early Saturday morning as a
strong frontal system approaches the region. Winds will be focused
along the western Kenai Peninsula coast as well as across Kachemak
Bay.

For communities along the western Kenai Peninsula coast, from
Nikiski to Anchor Point, expect sustained winds 20 to 35 mph with
gusts 45 to 55 mph. The strongest winds and gusts associated with
this system are expected between 10 am AKDT Friday and 4am AKDT
Saturday. Winds are expected to diminish through Saturday morning.

For communities along Kachemak Bay, from Homer to Seldovia,
expect sustained winds of 25 to 40 mph with gusts 50 to 65 mph.
The strongest winds and gusts associated with this system are
expected between 8 am AKDT Friday and 1am AKDT Saturday. Winds are
expected to quickly diminish Saturday morning.

Sustained winds over Kachemak Bay are expected to approach 35
mph, with gusts near 60 mph. Waves in Kachemak Bay will be
highest in the outer bay, with waves potentially reaching as high
as 8 to 12 ft. Waves closer to the Spit will be smaller, reaching
around 4 to 8 ft.

Strong winds may move loose debris, damage property, and cause
power outages. Travel may be difficult, especially for high
profile vehicles.

For the latest forecast information visit https://weather.gov/afc

SPECIAL WEATHER STATEMENT
National Weather Service ANCHORAGE AK
414 PM AKDT Wed Oct 9 2024

AKZ161-101500-
Bristol Bay-
Including the cities of King Salmon, Dillingham, Naknek,
and Pilot Point
414 PM AKDT Wed Oct 9 2024

...STRONG AND PERSISTENT WINDS THROUGHOUT THE GREATER BRISTOL BAY
AREA FRIDAY...

A deep low pressure system is expected to develop near Sand Point
on Friday, with its front pushing through Kamishak Gap and into
the greater Bristol Bay area and northern Alaska Peninsula.
Sustained winds are expected to be in the 35 to 50 mph range out
of the east and northeast, starting early Friday morning and
persisting into early Saturday. Gusts up to 65 mph are possible,
especially over higher terrain. Light rain will accompany the
winds. Please take time to secure loose items.