Heavy Freezing Spray Warning 129, NWS Anchorage, AK

836 
FZAK52 PAFC 231916 AAA
CWFALU

Coastal Waters Forecast...UPDATED
National Weather Service Anchorage Alaska
1116 AM AKDT Tue Mar 23 2021

Updated the Synopsis to include new information about Veniaminof
Volcano

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.

PKZ199-240830-
1116 AM AKDT Tue Mar 23 2021

.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA PENINSULA 
WATERS AND THE ALEUTIAN ISLANDS...

The Veniaminof Volcano is active today and located 20 miles north
of Perryville.

A front crosses the Aleutians and Bering Mon through Wed morning.
The front then becomes nearly stationary over the Southern Bering
as it weakens through Thu morning. Another front approaches the
Western Bering by Thu morning.

$$

PKZ150-240830-
South of the AK Peninsula Sitkinak to Castle Cape-
1116 AM AKDT Tue Mar 23 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...N wind 30 kt. Seas 11 ft. Freezing spray.
.TONIGHT...W wind 20 kt becoming SW 30 kt after midnight. Seas 9 ft. 
Freezing spray.
.WED...SW wind 30 kt. Seas 8 ft.
.WED NIGHT...SW wind 30 kt. Seas 9 ft.
.THU THROUGH FRI...W wind 25 kt. Seas 9 ft.
.SAT...W wind 30 kt. Seas 11 ft.

$$

PKZ155-240830-
South of the AK Peninsula Castle Cape to Cape Sarichef-
1116 AM AKDT Tue Mar 23 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...N wind 30 kt becoming W 15 kt in the afternoon. Seas 12
ft. Freezing spray.
.TONIGHT...SW wind 30 kt. Seas 7 ft.
.WED...SW wind 25 kt. Seas 8 ft.
.WED NIGHT...SW wind 25 kt. Seas 9 ft.
.THU...W wind 20 kt. Seas 9 ft.
.FRI THROUGH SAT...W wind 25 kt. Seas 10 ft.

$$

PKZ160-240830-
Bristol Bay-
1116 AM AKDT Tue Mar 23 2021

...HEAVY FREEZING SPRAY WARNING THROUGH WEDNESDAY...
...SMALL CRAFT ADVISORY TONIGHT AND WEDNESDAY...

.TODAY...N wind 20 kt becoming W 10 kt in the afternoon. Seas in
ice free waters 4 ft. Heavy freezing spray.
.TONIGHT...SW wind 30 kt. Seas in ice free waters 6 ft. Heavy
freezing spray. Snow.
.WED...SW wind 30 kt. Seas in ice free waters 7 ft. Heavy freezing
spray. Snow with rain.
.WED NIGHT...SW wind 25 kt. Seas in ice free waters 7 ft.
.THU...W wind 25 kt. Seas in ice free waters 6 ft.
.FRI...SW wind 20 kt. Seas in ice free waters 6 ft.
.SAT...W wind 25 kt. Seas in ice free waters 8 ft.

$$

PKZ165-240830-
Port Heiden to Cape Sarichef-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING TONIGHT...

.TODAY...N wind 25 kt becoming SW in the afternoon. Seas 9 ft.
Freezing spray through the day.
.TONIGHT...SW wind 35 kt. Seas 10 ft. Freezing spray. Snow and
rain.
.WED...SW wind 30 kt. Seas 14 ft. Freezing spray.  and snow.
.WED NIGHT...SW wind 30 kt. Seas 13 ft.
.THU THROUGH SAT...W wind 25 kt. Seas 12 ft.

$$

PKZ170-240830-
Cape Sarichef to Nikolski Bering Side-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...N wind 20 kt becoming SW 35 kt in the afternoon. Seas 9
ft. Freezing spray early.
.TONIGHT...SW wind 35 kt. Seas 10 ft building to 15 ft after
midnight. 
.WED...SW wind 30 kt. Seas 15 ft.
.WED NIGHT...SW wind 30 kt. Seas 14 ft.
.THU THROUGH FRI...W wind 25 kt. Seas 12 ft.
.SAT...SW wind 30 kt. Seas 13 ft.

$$

PKZ171-240830-
Unalaska Bay-
1116 AM AKDT Tue Mar 23 2021

...SMALL CRAFT ADVISORY TONIGHT AND WEDNESDAY...

.TODAY...N wind 20 kt becoming S in the afternoon. Seas 7 ft
subsiding to 2 ft in the afternoon. Freezing spray through the
day.
.TONIGHT...SW wind 30 kt. Seas 4 ft.
.WED...SW wind 25 kt. Seas 3 ft.
.WED NIGHT...SW wind 25 kt. Seas 3 ft.
.THU THROUGH SAT...SW wind 20 kt. Seas 3 ft.

$$

PKZ172-240830-
Cape Sarichef to Nikolski Pacific Side-
1116 AM AKDT Tue Mar 23 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...N wind 30 kt becoming SW in the afternoon. Seas 10 ft
subsiding to 6 ft in the afternoon.
.TONIGHT...SW wind 30 kt. Seas 8 ft.
.WED...SW wind 30 kt. Seas 10 ft.
.WED NIGHT...SW wind 30 kt. Seas 11 ft.
.THU...W wind 20 kt. Seas 10 ft.
.FRI...W wind 25 kt. Seas 10 ft.
.SAT...SW wind 30 kt. Seas 13 ft.

$$

PKZ173-240830-
Nikolski to Seguam Island Bering Side-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...Variable wind 10 kt becoming SW 40 kt. Seas 10 ft.
.TONIGHT...SW wind 35 kt. Seas 15 ft.
.WED...SW wind 30 kt. Seas 15 ft. Rain.
.WED NIGHT...W wind 25 kt. Seas 12 ft.
.THU THROUGH FRI...W wind 25 kt. Seas 11 ft.
.SAT...S wind 30 kt. Seas 16 ft.

$$

PKZ174-240830-
Nikolski to Seguam Island Pacific Side-
1116 AM AKDT Tue Mar 23 2021

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TODAY...N wind 15 kt becoming W in the morning, then becoming SW
30 kt in the afternoon. Seas 8 ft.
.TONIGHT...SW wind 30 kt. Seas 10 ft.
.WED...SW wind 30 kt. Seas 14 ft.
.WED NIGHT...W wind 30 kt. Seas 14 ft.
.THU...W wind 20 kt. Seas 10 ft.
.FRI...W wind 25 kt. Seas 10 ft.
.SAT...S wind 30 kt. Seas 20 ft.

$$

PKZ175-240830-
Seguam Island to Adak Bering Side-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...S wind 30 kt increasing to 40 kt. Seas 9 ft building to
14 ft in the afternoon.
.TONIGHT...SW wind 35 kt. Seas 15 ft. Rain.
.WED...SW wind 30 kt. Seas 11 ft. Rain.
.WED NIGHT...W wind 20 kt. Seas 8 ft.
.THU THROUGH FRI...SW wind 25 kt. Seas 11 ft.
.SAT...SE wind 30 kt. Seas 20 ft.

$$

PKZ176-240830-
Seguam Island to Adak Pacific Side-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING TODAY...

.TODAY...SW wind 20 kt increasing to 35 kt. Seas 10 ft.
.TONIGHT...SW wind 30 kt. Seas 15 ft.
.WED...S wind 30 kt. Seas 16 ft. Rain.
.WED NIGHT...W wind 20 kt. Seas 13 ft.
.THU THROUGH FRI...SW wind 20 kt. Seas 10 ft.
.SAT...S wind 30 kt. Seas 29 ft.

$$

PKZ177-240830-
Adak to Kiska-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...S wind 45 kt. Seas 12 ft building to 18 ft. Rain through
the day.
.TONIGHT...SW wind 35 kt. Seas 17 ft. Rain and snow.
.WED...NW wind 25 kt. Seas 13 ft.
.WED NIGHT...W wind 30 kt. Seas 12 ft.
.THU...W wind 25 kt. Seas 12 ft.
.FRI...SW wind 25 kt. Seas 12 ft.
.SAT...SE wind 35 kt. Seas 32 ft.

$$

PKZ178-240830-
Kiska to Attu-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING TODAY...

.TODAY...SW wind 45 kt becoming W 25 kt in the afternoon. Seas
22 ft. Rain and snow through the day.
.TONIGHT...W wind 20 kt. Seas 15 ft. Snow.
.WED...W wind 20 kt becoming SW 30 kt in the afternoon. Seas 12 ft. 
.WED NIGHT...W wind 30 kt. Seas 15 ft.
.THU...SW wind 30 kt. Seas 14 ft.
.FRI...S wind 30 kt. Seas 14 ft.
.SAT...SE wind 30 kt. Seas 26 ft.

$$

PKZ179-240830-
Pribilof Islands Near Shore Waters-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...S wind 15 kt increasing to 45 kt. Seas 7 ft building to
13 ft in the afternoon.  and freezing spray.
.TONIGHT...SW wind 35 kt diminishing to 25 kt after midnight. Seas
18 ft. Rain and snow.
.WED...SW wind 15 kt. Seas 14 ft. Snow.
.WED NIGHT...NW wind 15 kt. Seas 11 ft.
.THU...W wind 25 kt. Seas 9 ft.
.FRI...W wind 25 kt. Seas 15 ft.
.SAT...S wind 25 kt. Seas 15 ft.

$$

PKZ180-240830-
Kuskokwim Delta and Etolin Strait-
1116 AM AKDT Tue Mar 23 2021

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

.TODAY...N wind 25 kt becoming S 40 kt in the afternoon. Seas in
ice free waters 4 ft. and heavy freezing spray through the day.
.TONIGHT...SW wind 40 kt diminishing to 30 kt after midnight. Seas
in ice free waters 7 ft. Freezing spray. Snow.
.WED...SW wind 25 kt. Seas in ice free waters 8 ft. Heavy freezing
spray. Snow.
.WED NIGHT...W wind 25 kt. Seas in ice free waters 8 ft.
.THU THROUGH FRI...SW wind 20 kt. Seas in ice free waters 8 ft.
.SAT...W wind 20 kt. Seas in ice free waters 8 ft.

$$

PKZ181-240830-
North and West of Nunivak Island-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...S wind 15 kt increasing to 40 kt.
.TONIGHT...SW wind 35 kt diminishing to 25 kt after midnight.
.WED...SW wind 25 kt.
.WED NIGHT...W wind 15 kt.
.THU...Variable wind 10 kt.
.FRI...SW wind 15 kt.
.SAT...NW wind 20 kt.

$$

PKZ185-240830-
Saint Matthew Island Waters-
1116 AM AKDT Tue Mar 23 2021

...GALE WARNING TODAY...
...HEAVY FREEZING SPRAY WARNING TODAY...

.TODAY...E of Saint Matthew Island, S wind 30 kt increasing to
45 kt. W of Saint Matthew Island, S wind 45 kt becoming SW 35 kt
in the afternoon. Seas in ice free waters 13 ft building to 21 ft. 
Heavy freezing spray. Snow.
.TONIGHT...SW wind 30 kt. Seas in ice free waters 20 ft.
.WED...W wind 25 kt. Seas in ice free waters 16 ft.
.WED NIGHT...SW wind 20 kt. Seas in ice free waters 10 ft.
.THU...SW wind 25 kt. Seas in ice free waters 12 ft.
.FRI...W wind 25 kt. Seas in ice free waters 14 ft.
.SAT...NE wind 25 kt. Seas in ice free waters 17 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
504 PM AKDT Mon Mar 22 2021

.ANALYSIS AND UPPER LEVELS...

The weak ridge axis continues to move eastward and now stretches
north across eastern Prince William Sound and the eastern
interior. Under the ridge, conditions are generally clear with
light winds and cold temps.

Farther west, low pressure well south of the eastern Aleutians is
moving northeast toward Kodiak Island. A front associated with
this system is extending into the western Gulf. A secondary trough
is moving east over Southwest Alaska with light snow falling from
interior Bristol Bay into the Kuskokwim Valley.

For the Bering, an amplified ridge of high pressure is keeping
conditions rather tranquil for the western half of the Bering and
the Aleutian Chain. A northerly flow ahead of the ridge is
producing gusty winds and snow showers from the Pribilofs south to
Unalaska and Cold Bay. To the west of the ridge, another strong
low pressure system with an attendant trough is near the
Kamchatka Peninsula and moving east toward the western Bering.

&&

.MODEL DISCUSSION...

Models continue to be in excellent agreement overall for the next
several days. The surface low moving northeast toward the eastern
Aleutians and Kodiak Island will get caught up in the western
Alaska trough as it moves across south central Alaska and PWS
tomorrow. Kodiak and favored portions of eastern Chugach and
wester PWS will see mainly light snow accumulation.

Models also show good agreement for the next front to move quickly
onshore by Tuesday night over the Y-K Delta where there is good
confidence for snow and blowing snow with the frontal passage.
Ahead of the front, this strong storm system will bring Gale to
Storm Force winds to the western Bering overnight tonight.

That front will continue to quickly move east but begin to slow,
affecting the South Central region mainly Wednesday night through
Thursday, bringing another round of snow to the Anchorage area.

&&

.AVIATION...

PANC...Expect predominantly VFR conditions and light north winds
to continue through tonight. A disturbance moving in from the
west may bring a period of very light snow Tuesday morning,
potentially leading to MVFR conditions towards the end of the
period.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:Tonight
through Thursday afternoon)...

An upper level trough over the eastern Bering is in the process
of phasing with a trough and elongated surface low south of the
AKPen. Northeast flow of cold air aloft will help keep
precipitation over Kodiak Island as snow as the low moves into
the central Gulf Tuesday morning. Some light snow is possible
over the western Prince William Sound, western Kenai, Anchorage
Bowl and Mat-Su early Tuesday morning as the trough moves east and
through the area. Weak outflow winds and partly cloudy skies are
expected Tuesday afternoon and into Wednesday as mostly zonal flow
sets up aloft.

By Thursday there is a considerable amount of uncertainty as a
shortwave trough over the eastern Bering interacts with a ridge
over the north Pacific. Model guidance differs in whether or not
flow will remain zonal or become more amplified as the trough
moves towards Southcentral. This will dictate how much moisture
can be advected into the region from the southwest. If the flow
were to remain zonal, most of the moisture would be consumed by
the western Alaska Range before it makes it into the Cook Inlet
Region. If the flow shifts to the southwest, upslope areas of the
western Chugach and Talkeetna Mountains could receive a
considerable amount of snow. This forecast package reflects a
middle ground approach with snow totals ranging from 2 to 7 inches
from Anchorage north to the Mat-Su. Temperatures aloft should
remain cold enough for snow for the mainland, although the snow is
expected to be heavy with surface temperatures hovering around or
slightly above freezing.

&&

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

A blizzard warning for the Kuskokwim Delta coast remains
headlined in the forecast effective Tuesday afternoon at 4 PM
through 1 AM Wednesday. The heaviest snow amount lies in the path
of Y-K coast/delta until the front passes the warned area by
Wednesday morning. Increasing southwesterly winds are also
expected to reduce visibility mainly for Kuskokwim Delta and its
coast until the front passes. This front will also cause low
stratus clouds and fog to linger over Bristol Bay through at least
Wednesday afternoon. The amount of snow will continue to increase
as the front advances eastward the next couple days. Although
warmer westerlies will develop for Bristol Bay and AKPEN through
Thursday morning, precipitation is still expected to fall as snow
across the interior west of the Alaska Range with a rain/snow mix
over Bristol Bay and AKPEN between Wednesday and Thursday. Warm
temperatures will trend upward on Thursday, reaching into the
upper 30s which is also a reflection of the next mid to upper
ridge moving into Southwest AK beginning Thursday morning.

&&

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

A broad frontal system west of Shemya will usher storm force
winds for the western Aleutians tonight. This same frontal system
will elevate seas and wind conditions across the northern Bering
and the Aleutians until it reaches mainland Southwest AK late
Tuesday afternoon. Its trailing front merges to an emerging North
Pacific low, which will shift north past Amchitka Wednesday
morning into the central Bering Sea. Solutions are keeping this
low alive until it enters Bristol Bay area through Wednesday
night. Other interesting features to look out for are the west to
east motion of a couple of shortwaves from the western Bering,
which could bring additional snow over Pribilof and the Bering Sea
on Thursday and Thursday night. Overall, rain/snow mix will
persist over much of the Aleutians and near Pribilof Islands in
the next couple days.

&&

.MARINE (Days 3 through 5: Thursday through Saturday)...

Gulf of Alaska: There is a dome of high pressure south of the
Aleutian chain and a glimmer of a ridge axis over the GOA
Thursday. Friday the ridge will get pushed to the south and a
trough will bring a line of showers through the GOA. Saturday a
new organized low will move into the eastern Gulf but this storm
will predominately impact Southeast Alaska.

Bering: There are two weak fronts in the Bering Thursday. One is
between the Y-K Delta to the Pribilof Island to Dutch Harbor.The
other is near Kamchatka with the south edge of the boundary
clipping Attu and Shemya. Both of these boundaries push
southeastward with the leading system rapidly decaying.

&&

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

There is a noticeable amount of model divergence from the Being
to the Gulf Of Alaska. This section of the forecast package
reflects a blend of several models. There are a few items to
gleam past 96 hrs. At the onset of the forecast period, a
relatively amplified pattern on with a trough over the Eastern
Bering and ridge over the Eastern Pacific and the Gulf Of Alaska.
There is a weak frontal boundary over the Western Alaska Range and
portions of Southcentral. The Canadian, GFS and ECMWF have honed
in on another low near Kamchatka and the associated front will
another batch of precipitation from the Western Bering eastward
reaching Bethel by Saturday. The GFS and ECMWF are spinning up a
storm force low in the NW Pacific Saturday. However the past
several model runs the placement of the surface lows are more
than 300 miles apart and the ECMWF is 15 mb deeper with the
surface low by 18z Saturday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard Warning 155.
MARINE...Storm Warning 178.
		 Gale Warning 130 155 170 172 173 175-177 179-181 185
					  411-414.
		 Heavy Freezing Spray Warning 160 180 185 412 414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...NR
SOUTHCENTRAL ALASKA...CJ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
MARINE/LONG TERM...PJS