Storm Warning 153, NWS Anchorage, AK

440 
FZAK62 PAFC 150100
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
400 PM AKST Thu Nov 14 2024

Offshore Waters Forecast for the Bering Sea

Wind forecasts reflect the predominant speed and direction
expected. Sea forecasts represent an average of the highest
one-third of the combined wind wave and swell height.

PKZ499-151345-
400 PM AKST Thu Nov 14 2024
.SYNOPSIS FOR CENTRAL BERING SEA...

A 966 mb low at 58N 164W moves inland by early Fri morning. 
Several troughs move across the Bering Sea through Saturday 
afternoon. 

$$

PKZ411-151345-
Bering Sea Offshore West of 180 and East of the International
Dateline-
400 PM AKST Thu Nov 14 2024

.TONIGHT...NW wind 10 to 20 kt. Seas 8 ft.
.FRI...W wind 10 to 25 kt. Seas 9 ft.
.FRI NIGHT...NW wind 15 to 30 kt. Seas 8 to 11 ft.
.SAT...W wind 10 to 25 kt. Seas 6 to 11 ft.
.SAT NIGHT...W wind up to 15 kt. Seas 4 to 8 ft.
.SUN...SW wind up to 20 kt. Seas 3 to 6 ft.
.MON...S wind 15 to 30 kt. Seas 9 to 17 ft.
.TUE...SW wind 25 to 40 kt. Seas 19 to 27 ft.

$$

PKZ412-151345-
Bering Sea Offshore 171W to 180 and North of 56N-
400 PM AKST Thu Nov 14 2024

.TONIGHT...N wind 10 to 25 kt. Seas 9 to 13 ft.
.FRI...NW wind up to 15 kt. Seas 8 ft.
.FRI NIGHT...W wind 10 to 20 kt. Seas 7 ft.
.SAT...NW wind 15 to 25 kt. Seas 7 to 10 ft.
.SAT NIGHT...W wind 10 to 25 kt. Seas 6 to 10 ft.
.SUN...NW wind 10 to 25 kt. Seas 4 to 9 ft.
.MON...SW wind up to 20 kt. Seas 5 to 10 ft.
.TUE...S wind 20 to 30 kt. Seas 12 to 20 ft.

$$

PKZ413-151345-
Bering Sea Offshore 171W to 180 and South of 56N-
400 PM AKST Thu Nov 14 2024

.TONIGHT...NW wind 10 to 20 kt. Seas 8 to 11 ft.
.FRI...NW wind 10 to 20 kt. Seas 9 ft.
.FRI NIGHT...W wind 10 to 25 kt increasing to 20 to 30 kt after
midnight. Seas 7 to 10 ft. Rain showers and snow showers.
.SAT...W wind 15 to 30 kt. Seas 8 to 11 ft.
.SAT NIGHT...W wind 10 to 20 kt. Seas 6 to 10 ft.
.SUN...NW wind 10 to 25 kt. Seas 4 to 7 ft.
.MON...SW wind 10 to 20 kt. Seas 5 to 10 ft.
.TUE...S wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ414-151345-
Bering Sea Offshore East of 171W-
400 PM AKST Thu Nov 14 2024

.TONIGHT...NW wind 15 to 30 kt. Seas 10 to 16 ft.
.FRI...NW wind 10 to 25 kt. Seas 8 to 12 ft.
.FRI NIGHT...NW wind 10 to 20 kt. Seas 8 ft.
.SAT...W wind 15 to 30 kt. Seas 6 to 10 ft.
.SAT NIGHT...NW wind 20 to 30 kt. Seas 9 to 13 ft.
.SUN THROUGH MON...NW wind 15 to 30 kt. Seas 6 to 11 ft.
.TUE...SW wind up to 20 kt. Seas 4 to 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
446 PM AKST Wed Nov 13 2024

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

The majority of Southcentral remains in a lull in-between two
troughs and ridging built in to the north. The clear skies have
allowed for temperatures to drop further than previously expected
for even coastal areas this past morning. That said, a similar
pattern is expected for much of Southcentral again Thursday
morning, including the potential for areas of freezing fog to
develop along portions of the northern Cook Inlet. Temperatures
tonight and early Thursday morning likely to dip into the single
digits for most of Southcentral except coastal areas, with areas
of the Susitna Valley and Copper River Basin likely to reach low
temperatures in the negatives. The tight pressure gradient and
cold air advection will allow for gusty winds to remain in
Resurrection Bay, Passage Canal, Valdez Narrows, and Thompson Pass
through Thursday morning.

Southcentral is looking at a pattern change however beginning
Thursday morning for Kodiak Island as a frontal system enters the
western Gulf of Alaska. Kodiak to see rainfall begin Friday
morning, however should come to an end by noon Thursday as the
front shifts northward. As the front begins to move over the Kenai
Peninsula, it is likely that it will spin-up a triple-point low
in the Northwestern Gulf of Alaska. This organization will likely
maintain the system as it pushes up into the Peninsula and Prince
William Sound. As the system overspreads Southcentral Thursday
afternoon, precipitation will fill in the region from Cook Inlet
and the Mat-Su valleys west into Prince William Sound. With
plenty of cold air in place ahead of the front, precipitation will
start as snow for most of Southcentral, with warmer air moving in
coastal locations, a shift from all snow to a rain/snow mix is
possible. With those exceptions, Southcentral will see generally
snowy weather overspread the region, with the highest
accumulations expected in the Prince William Sound region. The
initial surge of moisture will likely allow for a quick shot of
light snowfall for Anchorage late Thursday afternoon before the
winds orientate in a more downslope favored pattern. For Portage
Valley and Turnagain Pass, the combination of snow and wind, at
least initially, may produce a period of blowing snow. Several
inches of snow is also possible for Valdez and Thompson Pass with
this system.

Given that the system organizes and pulls into a low pressure
system, precipitation is expected to persist into the early
weekend. By Friday morning, the low is expected to shift the wind
field and allow for a band of snowfall to re-establish from Palmer
to Kenai including Anchorage. This band on the backside of the
low is currently expected to lack a substantial moisture content
but a favorable persistence. This could indicate a potentially
long- duration very light snow event for Anchorage and the
surrounding area from Friday morning into Saturday.

-CL

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA/BERING SEA/ALEUTIANS (Days
1 through 3: Today through Saturday afternoon)...

A storm system currently near Adak will bring a suite of hazards
as it moves into and across Southwest Alaska through Friday. There
have been quite a few updates to the previous forecast as
improving model agreement has led to increased forecast
confidence. The biggest changes have been the issuance of the
following statements, advisories, and warnings:

* Kuskokwim Delta: Blizzard Warning for parts of Kuskokwim Delta
  north and west of the Kuskokwim River, including Nunivak Island.
* Lower Kuskokwim Valley: Winter Weather Advisory for 6-10 inches
  of snow.
* Bristol Bay: High Surf Advisory for Togiak Bay coastline.
  Special Weather Statement for Greater Bristol Bay due to gusty
  winds, blowing snow, and snow transitioning to rain.

Diving into the details... the focus for the short term forecast
continues to be a strong low that is currently near Adak. As the
low moves across the Pribilof Islands and towards Southwest
Alaska tonight, the Aleutian Islands, Alaska Peninsula, and
Pribilof Islands can expect to see rain and gusty winds. An area
of storm force winds will accompany the low center, with a
broad area of gales around the system itself. The strongest gusts
in the Bering Sea region tonight will likely be around Dutch
Harbor, with gusts to 60 kt or about 70 mph.

From just after midnight tonight through early tomorrow morning,
conditions will begin to deteriorate across Southwest Alaska as
the front moves in. Resident cold air and excellent moisture
advection with this low will lead to widespread snow. Gusty winds
will lead to blowing snow and visibility reductions for most of
Kuskokwim Delta, with blizzard conditions expected to the north
and west of Kuskokwim River where temperatures will stay the
coolest. Bristol Bay could see some blowing snow early on as winds
blow through Kamishak Gap. However, by Thursday afternoon, strong
southerly flow will usher in warmer air and transition snow to
rain. In addition to changing over the precipitation type, this
strong southerly flow will also lead to high surf along the Togiak
Bay coastline. For Lower Kuskokwim Valley, the persistent stream
of moisture advection will lead to a long duration of snowfall
through Thursday, though no blowing snow is expected as the valley
will be sheltered from strong winds.

Forecast confidence decreases for Friday as models disagree on
the track of the low across Southwest Alaska. What this means is
that there will be uncertainty in how quickly conditions improve
as the low departs into the Gulf of Alaska. Accordingly, forecast
snow amounts could shift, especially for the Winter Weather
Advisory for the Lower Kuskokwim Valley. While the details remain
uncertain, the overall weather pattern looks to be more benign as
we head from Friday into the weekend. Broad longwave troughing
will keep unsettled weather in the forecast, though only weaker
disturbances are expected. With northerly flow, expect gusty (but
weaker) winds to persist and for temperatures to trend cooler.

-Chen

&&

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

Sunday, a low over the northern Gulf of Alaska weakens and moves
southeast, reducing the persistent shortwave precipitation over
the Kenai Peninsula. As it departs, gale force wind will be pulled
southeast across the Alaska Peninsula and out of Cook Inlet. This
drier northerly flow will cause clearing skies and colder
conditions. Single digit temperatures are expected for most of
Southcentral Sunday night through Wednesday, with below zero
temperatures across the Copper River Basin, where lows dip into
the negative teens Tuesday and Wednesday.

To the west, a shortwave low over the Aleutian Chain moves
eastward on Sunday, strengthening to push a front of gale force
winds into the southern Gulf by Tuesday morning. In its wake, a
ridge builds across the Bering Sea and Southwest Monday and
Tuesday, before a front of a northern Kamchatka low pushes across
the Aleutian Chain and Bering Sea Tuesday to Wednesday.

&&.AVIATION...

PANC...VFR conditions and light winds will persist. Fog and low
cigs may redevelop under high pressure Thursday morning.

&&