Small Craft Advisory 999, NWS Anchorage, AK

072 
FZAK52 PAFC 150011
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
311 PM AKST Tue Dec 14 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.

PKZ199-151300-
311 PM AKST Tue Dec 14 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 962 mb Kamchatka low moves to 300 nm west of St Matthew Island 
at 975 mb Wed afternoon and moves to the Gulf of Anadyr Thu 
afternoon. Its front moves across the Bering through Wed night. A 
developing N Pacific low deepens to 975 mb while moving to 130 nm 
northeast of Shemya Thu afternoon.

$$

PKZ150-151300-
South of the AK Peninsula Sitkinak to Castle Cape-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 20 kt in the evening becoming variable 10 kt.
Seas 8 ft. Freezing spray near the coast before midnight.
.WED...S wind 15 kt. Seas 6 ft.
.WED NIGHT...SE wind 20 kt. Seas 7 ft. Rain and snow.
.THU AND THU NIGHT...W wind 25 kt. Seas 9 ft.
.FRI THROUGH SAT...W wind 30 kt. Seas 12 ft.
.SUN...W wind 25 kt. Seas 14 ft.

$$

PKZ155-151300-
South of the AK Peninsula Castle Cape to Cape Sarichef-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 15 kt increasing to 25 kt after midnight. From
the Shumagin Islands E, S wind 15 kt. Seas 8 ft.
.WED...S wind 20 kt. Seas 8 ft. Rain with snow.
.WED NIGHT...W wind 25 kt. Seas 9 ft. Rain.
.THU AND THU NIGHT...W wind 25 kt. Seas 10 ft.
.FRI THROUGH SAT...SW wind 35 kt. Seas 15 ft.
.SUN...SW wind 30 kt. Seas 18 ft.

$$

PKZ160-151300-
Bristol Bay-
311 PM AKST Tue Dec 14 2021

...BRISK WIND ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...E wind 25 kt.
.WED...E wind 25 kt.
.WED NIGHT...SE wind 25 kt. Snow with rain.
.THU AND THU NIGHT...SW wind 15 kt.
.FRI THROUGH SUN...SW wind 25 kt.

$$

PKZ165-151300-
Port Heiden to Cape Sarichef-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt except E 20 kt from Port Moller E. Seas
8 ft. Freezing spray from Port Moller E.
.WED...SE wind 25 kt. Seas 8 ft. Rain showers.
.WED NIGHT...S wind 25 kt becoming W 20 kt after midnight. Seas 7 
ft. Rain and snow.
.THU...W wind 20 kt. Seas 9 ft.
.THU NIGHT...SW wind 35 kt. Seas 9 ft.
.FRI...SW wind 40 kt. Seas 20 ft.
.SAT...SW wind 35 kt. Seas 20 ft.
.SUN...S wind 30 kt. Seas 18 ft.

$$

PKZ170-151300-
Cape Sarichef to Nikolski Bering Side-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt. Seas 11 ft. Rain showers.
.WED...S wind 25 kt. Seas 9 ft.
.WED NIGHT...SW wind 25 kt. Seas 10 ft.
.THU...W wind 25 kt. Seas 12 ft.
.THU NIGHT...S wind 40 kt. Seas 14 ft.
.FRI...W wind 35 kt. Seas 21 ft.
.SAT THROUGH SUN...S wind 40 kt. Seas 22 ft.

$$

PKZ171-151300-
Unalaska Bay-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 4 ft.
.WED...S wind 20 kt. Seas 3 ft. Rain showers.
.WED NIGHT...SW wind 15 kt. Seas 2 ft.
.THU...W wind 20 kt. Seas 3 ft.
.THU NIGHT...S wind 25 kt. Seas 4 ft.
.FRI THROUGH SAT...SW wind 30 kt. Seas 5 ft.
.SUN...S wind 25 kt. Seas 4 ft.

$$

PKZ172-151300-
Cape Sarichef to Nikolski Pacific Side-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 11 ft. Rain showers.
.WED...S wind 25 kt becoming W in the afternoon. Seas 11 ft.
.WED NIGHT...W wind 25 kt. Seas 12 ft.
.THU...W wind 25 kt. Seas 13 ft.
.THU NIGHT...SW wind 40 kt. Seas 14 ft.
.FRI...W wind 40 kt. Seas 14 ft.
.SAT THROUGH SUN...S wind 35 kt. Seas 22 ft.

$$

PKZ173-151300-
Nikolski to Seguam Island Bering Side-
311 PM AKST Tue Dec 14 2021

...GALE WARNING TONIGHT...

.TONIGHT...S wind 35 kt becoming SW 20 kt after midnight. Seas
14 ft. Rain.
.WED...SW wind 25 kt. Seas 9 ft.
.WED NIGHT...W wind 25 kt. Seas 12 ft.
.THU AND THU NIGHT...SW wind 40 kt. Seas 14 ft.
.FRI...W wind 35 kt. Seas 21 ft.
.SAT THROUGH SUN...S wind 40 kt. Seas 23 ft.

$$

PKZ174-151300-
Nikolski to Seguam Island Pacific Side-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt. Seas 16 ft. Rain.
.WED...W wind 25 kt. Seas 12 ft.
.WED NIGHT...W wind 25 kt. Seas 16 ft.
.THU...SW wind 30 kt. Seas 15 ft.
.THU NIGHT...SW wind 45 kt. Seas 17 ft.
.FRI...W wind 30 kt. Seas 16 ft.
.SAT THROUGH SUN...S wind 40 kt. Seas 28 ft.

$$

PKZ175-151300-
Seguam Island to Adak Bering Side-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 10 ft. Rain.
.WED...W wind 30 kt. Seas 12 ft.
.WED NIGHT...W wind 30 kt. Seas 14 ft.
.THU...SW wind 45 kt. Seas 13 ft.
.THU NIGHT...SW wind 40 kt. Seas 20 ft.
.FRI...SW wind 35 kt. Seas 19 ft.
.SAT THROUGH SUN...S wind 40 kt. Seas 20 ft.

$$

PKZ176-151300-
Seguam Island to Adak Pacific Side-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 17 ft. Rain.
.WED...W wind 30 kt. Seas 19 ft.
.WED NIGHT...W wind 25 kt. Seas 18 ft.
.THU AND THU NIGHT...SW wind 45 kt. Seas 17 ft.
.FRI...SW wind 30 kt. Seas 17 ft.
.SAT THROUGH SUN...S wind 45 kt. Seas 33 ft.

$$

PKZ177-151300-
Adak to Kiska-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 14 ft Bering side... 21 ft Pacific 
side.
.WED...W wind 30 kt. Seas 21 ft.
.WED NIGHT...W wind 30 kt. Seas 20 ft.
.THU...S wind 50 kt. Seas 20 ft.
.THU NIGHT...W wind 45 kt. Seas 21 ft.
.FRI...S wind 40 kt. Seas 23 ft.
.SAT...S wind 45 kt. Seas 34 ft.
.SUN...S wind 40 kt. Seas 29 ft.

$$

PKZ178-151300-
Kiska to Attu-
311 PM AKST Tue Dec 14 2021

...GALE WARNING THROUGH WEDNESDAY NIGHT...

.TONIGHT...W wind 40 kt. Seas 24 ft.
.WED...W wind 35 kt. Seas 24 ft.
.WED NIGHT...W wind 35 kt becoming S 35 kt after midnight. Seas 19 
ft. Snow with rain.
.THU...SW wind 55 kt. Seas 25 ft.
.THU NIGHT...W wind 45 kt. Seas 23 ft.
.FRI THROUGH SAT...S wind 50 kt. Seas 32 ft.
.SUN...S wind 40 kt. Seas 33 ft.

$$

PKZ179-151300-
Pribilof Islands Near Shore Waters-
311 PM AKST Tue Dec 14 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...S wind 30 kt. Seas 15 ft. Rain showers.
.WED...S wind 20 kt. Seas 12 ft.
.WED NIGHT...SW wind 20 kt. Seas 12 ft.
.THU...SW wind 20 kt. Seas 12 ft.
.THU NIGHT...S wind 40 kt. Seas 15 ft.
.FRI...SW wind 50 kt. Seas 26 ft.
.SAT THROUGH SUN...S wind 40 kt. Seas 26 ft.

$$

PKZ180-151300-
Kuskokwim Delta and Etolin Strait-
311 PM AKST Tue Dec 14 2021

...GALE WARNING THROUGH WEDNESDAY...
...HEAVY FREEZING SPRAY WARNING TONIGHT...

.TONIGHT...SE wind 35 kt. Heavy freezing spray.
.WED...SE wind 35 kt. Snow.
.WED NIGHT...SE wind 30 kt becoming S 20 kt after midnight.  Snow.
.THU...SW wind 15 kt.
.THU NIGHT...S wind 35 kt.
.FRI...SW wind 35 kt.
.SAT THROUGH SUN...S wind 30 kt.

$$

PKZ181-151300-
North and West of Nunivak Island-
311 PM AKST Tue Dec 14 2021

...GALE WARNING THROUGH WEDNESDAY...

.TONIGHT...E wind 40 kt.
.WED...SE wind 40 kt diminishing to 30 kt in the afternoon. Snow showers.
.WED NIGHT...S wind 25 kt diminishing to 15 kt after midnight.
.THU...SW wind 20 kt.
.THU NIGHT...S wind 35 kt.
.FRI THROUGH SAT...S wind 30 kt.
.SUN...S wind 35 kt.

$$

PKZ185-151300-
Saint Matthew Island Waters-
311 PM AKST Tue Dec 14 2021

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

.TONIGHT...E of Saint Matthew Island, SE wind 45 kt. W of Saint
Matthew Island, SE wind 50 kt becoming S 30 kt after midnight. Seas 
17 ft. Heavy freezing spray N of Saint Matthew Island in the evening.
Snow. Snow with rain from Saint Matthew Island S.
.WED...S wind 30 kt. Seas 16 ft.
.WED NIGHT...S wind 25 kt. Seas 17 ft.
.THU...SW wind 25 kt. Seas 13 ft.
.THU NIGHT...SE wind 30 kt. Seas 10 ft.
.FRI...W wind 30 kt. Seas 14 ft.
.SAT...SE wind 40 kt. Seas 24 ft.
.SUN...S wind 40 kt. Seas 35 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
544 PM AKST Mon Dec 13 2021

.ANALYSIS AND UPPER LEVELS...

A sprawling front extends from eastern Russia across the northern
and eastern Bering. A low is forming near Sand Point at the
southern end of the front. Arctic high pressure centered over the
northern part of the state is keeping temperatures as much as 20
to 30 degrees below normal across much of the mainland. Cloud
cover associated with the front has overspread all of Southwest
Alaska and much of Southcentral. A weak front is stalled over the
eastern Prince William Sound, resulting in light snow over
Cordova, and is slowly spreading north towards Valdez. Gap winds
continue through the Matanuska Valley and Thompson Pass.

The upper level pattern is very progressive this afternoon. A
pair of ridges are over the western Bering and the western Gulf,
respectively, with a shortwave trough in between. There's also a
large upper level trough over the northern half of the state.

&&

.MODEL DISCUSSION...

The models are in very good agreement on the large scale synoptic
features across southern Alaska this afternoon. However, there is
still a fair bit of inconsistency on the smaller features embedded
in the large scale pattern. The areas of lower confidence include
how much snow will fall over the next 2 days over eastern Prince
William Sound up through the Copper River Basin, how far north
impactful snow will get as the front moving into Southwest Alaska
reaches the Cook Inlet region this evening, and how impactful the
expected snow and blowing snow will be over Kodiak Island.
Forecast confidence is average.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist to start the
evening. Snow may develop around midnight, but if it develops at
all, it will be light. The snow will end around 3am. MVFR ceilings
are likely both during and following the snow, with visibilities
falling to MVFR during the snowfall. Ceilings will improve Tuesday
morning back to VFR. Confidence in snow is moderate, but is high
that any accumulations will be a half inch or less.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 to 3: tonight through
Thursday)...

Two main features in the Gulf are set to produce active weather
across Southcentral through Wednesday. The first is a surface low
passing south of Kodiak Island this evening, expected to transit
the southern Gulf and exit into the North Pacific by Tuesday
afternoon. From this system, Kodiak Island is expected to see 3
to 5 inches of snow through early Tuesday morning, with the
potential for some blowing snow to reduce visibilities at times.
Snow accumulations decrease further north, with the main impact
from the system being cloud cover and warmer temperatures. While
Anchorage is expected to see some precipitation, it is likely to
be in the form of flurries, with only minimal accumulations, as
dry air flowing in on the northern periphery of the system is
likely to evaporate much of the snow on its way down.

The second significant feature is a weak surface trough lingering
in the northern Gulf through Wednesday morning. Moist southerly
flow, aided by the low skirting the southern Gulf will bring
several inches of snow to the Eastern Prince William Sound area.
Most significant snowfall totals will occur along the coast near
Cordova, however, a Winter Weather Advisory was issued for
Thompson Pass, where 4 to 7 inches of snow is expected to combine
with gusty winds to produce blowing snow with low visibilities
dropping as low as one half mile. Tuesday night, a northwesterly
push of cold, dry air is expected to cut off the moisture and push
the trough off into the eastern Gulf, resulting in snow
diminishing through early Wednesday.

Gusty gap winds will also persist through Wednesday night as cold
air from the Interior continues to trickle out across the coastal
mountains. By Thursday, upper-level ridging and broad southerly
flow ahead of a low entering the western Gulf relaxes temperature
and pressure gradients, leading to diminishing gap flow.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Day 1 through 3...Tonight
through Thursday afternoon)...

An area of low pressure that formed along a frontal boundary near
Sand Point will continue to bring near blizzard conditions to the
Bristol Bay coastline through this evening. Very cold temperatures
in the single digits below zero with gusty winds upwards of 35 mph
will make way for very cold wind chills as low as 35 below zero as
well while it is snowing. Therefore, a Blizzard Warning remains
in effect through 9 PM this evening due to the gusty winds and
reduced visibility. Additional snow accumulations of 2 to 4
inches are expected through this evening especially around the
Port Heiden to Pilot Point area with a general 1 to 2 inches of
additional snow accumulation for King Salmon to Dillingham and
points north and west. Conditions will gradually improve this
evening for the Bristol Bay area as the snow tapers off and
pressure gradient relaxes diminishing the winds.

Next, skies are expected to clear overnight as the front decays
over the area. The pressure gradient is expected to remain across
the Kuskokwim Delta keeping wind chills very cold around 35 below
zero. Therefore, with Arctic air being pulled back southward from
the interior of Alaska, expect another frigid morning on Tuesday
with lows in the teens to 20s below zero especially across the
interior Kusko Delta and Kuskokwim Valley. Where winds are light,
and sky clear, temperatures may approach 25 below zero in spots.
For Bristol Bay, temperatures will mainly be in the single digits
below zero with single numbers for around Pilot Point to Port
Heiden.

Tuesday and Tuesday night will remain quiet and dry for Southwest
but with Arctic cold once again in place. Temperatures expected
to be in the teens to single numbers below zero with near zero
for coastal areas during the day and then teens to 20s below zero
overnight with single digits below zero for coastal areas. Another
storm system is expected to approach the area for Wednesday
through Thursday with widespread snowfall, rising temperatures,
and gusty winds especially for the coast resulting in potential
blowing snow and visibility concerns. Stay tuned as we get closer
to the event and fine tune the forecast.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Day 1 through
3...Tonight through Thursday afternoon)...

Another Kamchatka low continues moving northward towards East
Russia tonight through Tuesday. As a result, expect an area of
storm force winds east of Shemya from now through this evening
with another area of storms in the marine waters west of Saint
Matthew Island for Tuesday morning through Tuesday evening as this
system reinvigorates the previous front. Expect widespread seas of
15 to 25 ft as well with the highest seas where the area of
strongest winds are. This system will have a great deal of warm
air with it resulting in mostly rain for the Aleutian Chain this
time around as places will be starting warmer with much less cold
air in place.

Then, on the backside of the low, much colder air will move back
across much of the Bering for Tuesday evening through Wednesday
night resulting in widespread rain and snow showers for the
Aleutian Island Chain.

Lastly, another compact but strong storm force low is expected to
move northward towards Shemya late Wednesday/early Thursday
bringing another round of warmer air, rain and snow, and strong
gusty winds.

&&

.MARINE (Days 3 through 5)...

Gulf of Alaska: Expect winds less than 35 kts and seas less than
20 ft for the Day 3 through 5 period.

Bering Sea: A series of lows track across the Bering Thursday
through Saturday. Widespread gales and seas approaching 20 ft are
likely with each system. Areas of northerly storm force winds or
wind gusts are possible on Thursday night behind the first low,
with 20-25 ft. The following Friday night is the front off a
Kamchatka low pushing into the western Bering. Another round of
storm force winds with seas 20-30 ft possible along the front.

&&

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

A pattern change is expected during the extended period as strong
upper level ridging builds across the area from the eastern Bering
Sea through Southcentral Alaska. There is a medium to high degree
of ensemble consistency the ridge-axis will remain over Southwest
Alaska during this time. The surface pattern is also expected to
change from an offshore to onshore flow pattern as the ridge over
the Alaska Interior will weaken while the ridging off shore
associated with the aforementioned upper level ridge will
strengthen. This will allow for warmer temperatures to enter the
region. This pattern change will also allow for a greater chance
of moisture entering the region due to the change from off shore
to onshore flow. There is currently a moderate degree of agreement
that a weakening low will move inland on Saturday and bring snow
to the Kuskokwim Delta and Bristol Bay. A warm front is expected
to move across Southwest Alaska on Sunday and Monday and bring a
mix of snow and rain throughout the region. Confidence is low with
the specifics of this front at this time due to differences
between guidance.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard Warning 161.
		 Winter Weather Advisory 131.
MARINE...Storm Warning 178 185.
		 Gale Warning 130 131 132 139 170 173-177 180 181.
		 Heavy Freezing Spray Warning 121 127 130 139 140 150 160
									  165 180 181 185.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...JW
SOUTHCENTRAL ALASKA...CQ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MV
MARINE/LONG TERM...ED/KM