Small Craft Advisory 990, NWS Anchorage, AK

237 
FZAK52 PAFC 111610
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage AK
710 AM AKST Sat Dec 11 2021

Coastal Waters Forecast for Southwest Alaska+Bristol Bay+The
Alaska Peninsula Waters and the Aleutian Islands up to 100 nm out.

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.

PKZ199-120415-
710 AM AKST Sat Dec 11 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 988 mb North Pacific low moves to 56N 165E at 971 mb by Mon 
morning. Its front tracks across the Aleutians through Mon 
morning.

$$

PKZ150-120415-
South of the AK Peninsula Sitkinak to Castle Cape-
710 AM AKST Sat Dec 11 2021

...STORM WARNING THROUGH SUNDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...

.TODAY...NW wind 55 kt with gusts to 75 kt out of bays and 
passes. Seas 23 ft. Heavy freezing spray. 
.TONIGHT...NW wind 55 kt with gusts to 65 kt out of bays and 
passes. Seas 20 ft. Heavy freezing spray. 
.SUN...NW wind 55 kt. Seas 18 ft. Heavy freezing spray. 
.SUN NIGHT...NW wind 45 kt. Seas 13 ft. 
.MON...E wind 30 kt. Seas 9 ft. 
.TUE...NW wind 20 kt. Seas 9 ft. 
.WED...S wind 25 kt. Seas 8 ft.

$$

PKZ155-120415-
South of the AK Peninsula Castle Cape to Cape Sarichef-
710 AM AKST Sat Dec 11 2021

...STORM WARNING THROUGH TONIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH TONIGHT...

.TODAY...NW wind 40 kt, except NW 50 kt from the Shumagin Islands
E. Gusts to 65 kt out of bays and passes E of the Shumagin
Islands. Seas 15 ft. Heavy freezing spray, mainly E of the 
Shumagin Islands.
.TONIGHT...NW wind 40 kt, except NW 50 kt from the Shumagin 
Islands E. Gusts to 65 kt out of bays and passes E of the 
Shumagin Islands. Seas 14 ft. Heavy freezing spray, mainly E of
the Shumagin Islands.
.SUN...NW wind 40 kt. Seas 12 ft. Freezing spray. 
.SUN NIGHT...NE wind 30 kt. Seas 8 ft. 
.MON...SE wind 35 kt. Seas 11 ft. 
.TUE THROUGH WED...S wind 25 kt. Seas 11 ft.

$$

PKZ160-120415-
Bristol Bay-
710 AM AKST Sat Dec 11 2021

...GALE WARNING THROUGH SUNDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...

.TODAY...NW wind 45 kt. Seas in ice free waters 12 ft. Heavy
freezing spray. 
.TONIGHT...NW wind 40 kt. Seas in ice free waters 10 ft. Heavy
freezing spray and blowing snow. 
.SUN...NW wind 35 kt diminishing to 25 kt in the afternoon. Seas
in ice free waters 9 ft. Heavy freezing spray. 
.SUN NIGHT...NE wind 20 kt. Seas in ice free waters 5 ft. 
.MON...NE wind 30 kt. Seas in ice free waters 5 ft. 
.TUE...NE wind 20 kt. Seas in ice free waters 4 ft. 
.WED...SE wind 20 kt. Seas in ice free waters 5 ft.

$$

PKZ165-120415-
Port Heiden to Cape Sarichef-
710 AM AKST Sat Dec 11 2021

...GALE WARNING THROUGH SUNDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...

.TODAY...NW wind 40 kt. Seas 16 ft. Heavy freezing spray. Snow 
showers. 
.TONIGHT...NW wind 40 kt. Seas 14 ft. Heavy freezing spray. 
.SUN...N wind 30 kt diminishing to 20 kt in the afternoon. From
Port Moller E, NW wind 35 kt. Seas 11 ft. Heavy freezing spray. 
.SUN NIGHT...NE wind 30 kt. Seas 7 ft. 
.MON...SE wind 35 kt. Seas 9 ft. 
.TUE...SE wind 25 kt. Seas 8 ft. 
.WED...S wind 25 kt. Seas 9 ft.

$$

PKZ170-120415-
Cape Sarichef to Nikolski Bering Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TODAY...

.TODAY...NW wind 35 kt. Seas 14 ft. 
.TONIGHT...NW wind 30 kt becoming N 20 kt after midnight. Seas
13 ft. Freezing spray. 
.SUN...NE wind 20 kt becoming E 30 kt in the afternoon. Seas
8 ft. 
.SUN NIGHT...SE wind 45 kt. Seas 13 ft. 
.MON...SW wind 40 kt. Seas 12 ft. 
.TUE THROUGH WED...SW wind 30 kt. Seas 12 ft.

$$

PKZ171-120415-
Unalaska Bay-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TODAY...

.TODAY...NW wind 35 kt. Gusts to 45 kt. Seas 10 ft. Widespread 
snow showers.
.TONIGHT...NW wind 30 kt diminishing to 20 kt after midnight.
Seas 9 ft. 
.SUN...N wind 10 kt becoming E 20 kt in the afternoon. 
Seas 5 ft. Snow. 
.SUN NIGHT...SE wind 35 kt. Seas 4 ft. 
.MON...W wind 30 kt. Seas 4 ft. 
.TUE THROUGH WED...SW wind 20 kt. Seas 3 ft.

$$

PKZ172-120415-
Cape Sarichef to Nikolski Pacific Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TODAY...

.TODAY...NW wind 35 kt. Seas 11 ft. 
.TONIGHT...NW wind 30 kt. Seas 10 ft. 
.SUN...E wind 25 kt. Seas 5 ft.  and rain. 
.SUN NIGHT...SE wind 40 kt. Seas 11 ft. 
.MON...W wind 35 kt. Seas 11 ft. 
.TUE THROUGH WED...SW wind 30 kt. Seas 14 ft.

$$

PKZ173-120415-
Nikolski to Seguam Island Bering Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING SUNDAY...

.TODAY...W wind 25 kt. Seas 13 ft. 
.TONIGHT...W wind 15 kt becoming SE after midnight. Seas 8 ft.
Rain showers. 
.SUN...SE wind 30 kt increasing to 40 kt in the afternoon. Seas
7 ft building to 12 ft in the afternoon. Rain and snow. 
.SUN NIGHT...SE wind 45 kt. Seas 15 ft. 
.MON...SW wind 30 kt. Seas 12 ft. 
.TUE...S wind 35 kt. Seas 13 ft. 
.WED...SW wind 30 kt. Seas 13 ft.

$$

PKZ174-120415-
Nikolski to Seguam Island Pacific Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING SUNDAY...

.TODAY...W wind 25 kt. Seas 11 ft. 
.TONIGHT...W wind 15 kt. Seas 7 ft. 
.SUN...SE wind 30 kt increasing to 40 kt in the afternoon.  Seas
8 ft building to 13 ft in the afternoon. Rain and snow. 
.SUN NIGHT...S wind 45 kt. Seas 13 ft. 
.MON...W wind 30 kt. Seas 15 ft. 
.TUE...S wind 30 kt. Seas 16 ft. 
.WED...SW wind 30 kt. Seas 16 ft.

$$

PKZ175-120415-
Seguam Island to Adak Bering Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...SW wind 20 kt. Seas 10 ft. 
.TONIGHT...S wind 25 kt becoming SE 35 kt after midnight.  Seas
8 ft. Rain and snow. 
.SUN...SE wind 45 kt. Seas 13 ft. Rain. 
.SUN NIGHT...S wind 45 kt. Seas 12 ft. 
.MON THROUGH WED...SW wind 35 kt. Seas 14 ft.

$$

PKZ176-120415-
Seguam Island to Adak Pacific Side-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...SW wind 15 kt. Seas 7 ft. 
.TONIGHT...S wind 25 kt becoming SE 35 kt after midnight.  Seas
6 ft building to 12 ft after midnight. Rain. 
.SUN...SE wind 40 kt. Seas 15 ft. Rain. 
.SUN NIGHT...S wind 35 kt. Seas 14 ft. 
.MON THROUGH TUE...S wind 35 kt. Seas 19 ft. 
.WED...SW wind 30 kt. Seas 20 ft.

$$

PKZ177-120415-
Adak to Kiska-
710 AM AKST Sat Dec 11 2021

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...S wind 20 kt becoming SE 30 kt in the afternoon.  Seas
7 ft. Rain. 
.TONIGHT...SE wind 40 kt. Seas 17 ft. Rain and snow. 
.SUN...SE wind 40 kt. Seas 17 ft. Rain. 
.SUN NIGHT...SW wind 35 kt. Seas 20 ft. 
.MON THROUGH TUE...S wind 40 kt. Seas 21 ft. 
.WED...SW wind 35 kt. Seas 23 ft.

$$

PKZ178-120415-
Kiska to Attu-
710 AM AKST Sat Dec 11 2021

...STORM WARNING TONIGHT...

.TODAY...SE wind 30 kt becoming E 45 kt in the afternoon. Bering
side, seas 8 ft. Pac side, seas 7 ft building to 16 ft in the
afternoon. Rain and snow. 
.TONIGHT...SE wind 50 kt. Seas 18 ft. Rain and snow. 
.SUN...SE wind 40 kt. Seas 18 ft. Rain. 
.SUN NIGHT...SW wind 40 kt. Seas 23 ft. 
.MON...S wind 45 kt. Seas 23 ft. 
.TUE THROUGH WED...SW wind 40 kt. Seas 26 ft.

$$

PKZ179-120415-
Pribilof Islands Near Shore Waters-
710 AM AKST Sat Dec 11 2021

...SMALL CRAFT ADVISORY THROUGH SUNDAY...

.TODAY...NW wind 30 kt. Seas 11 ft. Freezing spray. 
.TONIGHT...N wind 25 kt diminishing to 15 kt after midnight. Seas
9 ft. Freezing spray. 
.SUN...E wind 20 kt increasing to 30 kt in the afternoon.  Seas
6 ft. Freezing spray. Snow showers. 
.SUN NIGHT...E wind 45 kt. Seas 17 ft. 
.MON...SW wind 40 kt. Seas 16 ft. 
.TUE THROUGH WED...S wind 30 kt. Seas 15 ft.

$$

PKZ180-120415-
Kuskokwim Delta and Etolin Strait-
710 AM AKST Sat Dec 11 2021

...GALE WARNING THROUGH SUNDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...

.TODAY...NW wind 40 kt. Seas in ice free waters 9 ft. Heavy
freezing spray. Snow showers. 
.TONIGHT...N wind 40 kt. Seas in ice free waters 9 ft. Heavy
freezing spray. 
.SUN...N wind 35 kt diminishing to 25 kt in the afternoon. Seas
in ice free waters 7 ft. Heavy freezing spray. 
.SUN NIGHT...NE wind 30 kt. Seas in ice free waters 4 ft. 
.MON...E wind 40 kt. Seas in ice free waters 11 ft. 
.TUE...E wind 30 kt. Seas in ice free waters 7 ft. 
.WED...S wind 30 kt. Seas in ice free waters 9 ft.

$$

PKZ181-120415-
North and West of Nunivak Island-
710 AM AKST Sat Dec 11 2021

...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...
...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...N wind 25 kt. Seas in ice free waters 8 ft. Heavy
freezing spray. Snow showers. 
.TONIGHT...N wind 25 kt. Seas in ice free waters 8 ft. Heavy
freezing spray. 
.SUN...N wind 20 kt. Seas in ice free waters 5 ft. Heavy freezing
spray. 
.SUN NIGHT...E wind 35 kt. Seas in ice free waters 7 ft. 
.MON...E wind 40 kt. Seas in ice free waters 9 ft. 
.TUE...E wind 35 kt. Seas in ice free waters 10 ft. 
.WED...SE wind 30 kt. Seas in ice free waters 11 ft.

$$

PKZ185-120415-
Saint Matthew Island Waters-
710 AM AKST Sat Dec 11 2021

...GALE WARNING SUNDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SUNDAY...

.TODAY...NW wind 25 kt. Seas 8 ft. Heavy freezing spray. 
.TONIGHT...N wind 20 kt. Seas 7 ft. Heavy freezing spray. 
.SUN...E of Saint Matthew Island, NE wind 15 kt becoming E 25 kt
in the afternoon. W of Saint Matthew Island, E wind 30 kt
increasing to 45 kt in the afternoon. Seas 5 ft building to 10 ft
in the  afternoon. Heavy freezing spray. 
.SUN NIGHT...E wind 55 kt. Seas 25 ft. 
.MON...E wind 50 kt. Seas 25 ft. 
.TUE...E wind 45 kt. Seas 20 ft. 
.WED...SE wind 25 kt. Seas 15 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
453 PM AKST Fri Dec 10 2021

.ANALYSIS AND UPPER LEVELS...
A deep vertically stacked low over the northern Gulf is beginning
to slowly exit off to the south and east. The bulk of snow
associated with the low center has moved offshore. Areas of
flurries or light snow linger over interior Southcentral as weak
upper level short-waves travel southward and low level cold air
advection begins. Pressure gradients along with the cold air
advection are leading to strengthening gap winds along the Gulf
and Prince William Sound coasts. The core of strongest cold air
advection is on the back side of the upper trough, from Southwest
Alaska southward to the Alaska Peninsula. This is leading to
widespread gusty winds across the region, with the strongest
winds out of bays and passes along the south side of the Alaska
Peninsula. Cold air advection across the eastern Bering Sea is
producing snow showers and gusty winds, with intermittent low
visibilities in snow and blowing snow from the Pribilof Islands
to Eastern Aleutians and Alaska Peninsula. Conditions are quiet
for the moment across the western Bering and Aleutians as a strong
upper level ridge builds in from the south and west.

&&

.MODEL DISCUSSION...
Models remain in good agreement with the large scale pattern over
the next few days. The forecast challenge will be the details of
winds and temperatures this weekend.

&&

.AVIATION...
PANC...VFR conditions will persist. The challenge for the forecast
will be winds. Low level cold air advection will increase low
level northerly winds tonight. However, not sure there is enough
forcing to mix these down to the surface. Gusty northerly winds
seem most likely during the day Saturday as the cold air advection
continues and likely overwhelms any low level inversion, resulting
in more vertical mixing of the wind.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 to 3: Tonight
through Monday morning)...

The low responsible for the most recent winter weather over the
Kenai Peninsula and much of the Prince William Sound area has now
migrated out into the northern Gulf, with snowfall now ended over
land for all but a few spots along the North Gulf Coast. Light
snow showers are also persisting over parts of the eastern Kenai
Peninsula, with snow also making it into Anchorage earlier in the
day with a weak northerly shortwave moving through. Another weak
wave aloft will drop across the Mat-Su Valleys from the Talkeetna
Mountains this evening, perhaps leading to renewed areas of light
snow or flurries that will result in little to no accumulation.

With the snow now ending area-wide, attention now turns more to
the major cold air outflow/gap wind event expected to unfold for
favored locations along the North Gulf Coast (Copper River Delta,
Valdez Arm, Passage Canal and Resurrection Bay) and more notably
along the northern Alaska Peninsula and around Kodiak. An Arctic
airmass will begin to make greater headway southward into much of
Southcentral and Southwest, increasing cold air advection along
the Alaska Peninsula and North Gulf Coast through Saturday. The
deep area of low pressure will remain situated over the Gulf
through the weekend as a northwest to southeast oriented upper jet
approaches the northern Alaska Peninsula and Kodiak, keeping the
pressure gradient along the coast exceptionally strong and aiding
forcing/subsidence associated with the intruding cold air mass.
This will produce extremely strong winds along bays and passes out
along the Alaska Peninsula, with Hurricane force winds developing
through parts of Shelikof Strait and near the Barren Islands
tonight. Winds will not be quite as strong around Kodiak Island,
but peak gusts are again expected to reach near 80 mph beginning
late tonight and lasting throughout the day Saturday. See the High
Wind Warning that has been issued with this package for further
details. The extremely strong winds coupled with temperatures
cooling into the 10s and 20s will cause areas of very heavy
freezing spray, again most notably near the Barren Islands and
Shelikof Strait. Mariners in the area should use extreme caution
as long as these conditions persist, with the more significant
winds and heavy freezing spray expected to continue well into
Sunday.

The main story away from marine areas will be the very cold
temperatures filtering in with the return of the Arctic air. Winds
will initially be strong enough to hold temperatures above 0F for
most areas through Saturday, but the cold will eventually win out
as skies begin to clear out and winds calm, helping lows to drop
in the -0s to -10s for lows on Sunday morning and again on Monday
for most of the interior. Low wind chills are possible where
winds remain higher, especially through Isabel and Broad Passes.

&&

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

A break in the active weather is expected for Southwest Alaska
over the next couple of days as upper level ridging slowly moves
in from the west. This will allow for a gradual easing of the
brisk northwesterly winds over the next couple of days. Cold
temperatures are also expected with inland portions remaining
subzero. The likelihood for snowfall will continue to decrease
across Southwest Alaska, except for areas along the Alaska
Peninsula as convective snow showers will continue to move
southeastward across the Alaska Peninsula.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...

An active weather pattern remains across the Bering/Aleutians over
the next few days. Strong northwesterly winds will allow for this
cold air advection pattern to continue producing ocean-effect
snow showers across the central to eastern Bering/Aleutians. The
strongest winds will be across the coastal waters south of the
Alaska Peninsula and Eastern Aleutians Saturday and Sunday as
widespread storm force winds are expected with hurricane force
gusts in areas prone to funneling from the northwest. The next
front will enter the western Bering/Aleutians Saturday night and
gradually move eastward to the eastern Bering/Aleutians Monday
afternoon and then stalling out over the area. This front will
bring warmer temperatures for much of the Bering/Aleutians due to
warm air advection in the wake of the front. This front will also
bring a mix of rain and snow to the Aleutians which will gradually
change from snow to rain from west to east.

&&

.MARINE (Days 3 through 5/Monday through Wednesday)...

Expect active weather across the Bering Sea, Aleutians, and
Southwest coast for the coming week, with fast moving storm
systems and rapidly changing conditions. Storms will generally
track from southwest to northeast across the Bering Sea.
Expect widespread gale force winds across the region, with
potential for smaller areas of storm force winds. The Gulf
of Alaska waters look much quieter, with some weaker systems
passing nearby.

&&

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

It looks like a very stormy week across the Bering Sea, Aleutians,
and Southwest Alaska. The general storm track will be from
southwest to northeast across the Bering Sea. Progressive flow
aloft will lead to fast moving systems and rapidly changing
weather. The main threat to Southwest Alaska will be snow and
blowing snow, especially along the coast. For the Bering Sea and
Aleutians, warmer air accompanying these systems will generally
produce rain early in the week, while a shift in upper flow later
in the week could cause a change back to snow. Nonetheless,
expect periods of strong winds with each of these systems.

Southcentral Alaska will start out quiet, with perhaps a glancing
blow of light snow Monday night-Tuesday from a low crossing the
southern Gulf of Alaska. Weather will become more active for the
second half of the week as upper level flow shifts and storms
crossing the Bering continue eastward across mainland Alaska.
This will bring additional chances of snow. With the strength of
the upper level flow, each shot of snow would be brief. As for
temperatures, the week will start out in the deep freeze, but
would expect moderation of temperatures as we head through the
week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 171.
MARINE...Storm 131-137 150 155 178
		 Hurricane Force Wind 130 138
		 Heavy Freezing Spray 119-125 129-165 180-185
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...SEB
SOUTHCENTRAL ALASKA...AS
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...ED
MARINE/LONG TERM...SEB