Storm Warning 47, NWS Anchorage, AK

652 
FZAK52 PAFC 140033
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
333 PM AKST Mon Feb 13 2023

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.

PKZ199-141330-
333 PM AKST Mon Feb 13 2023
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 970 mb low at 100 nm south of Atka moves into the North Pacific
at 990 mb Tue morning. A 935 mb North Pacific low and front 
approaches the western Aleutians Tue morning.

$$

PKZ150-141330-
South of the AK Peninsula Sitkinak to Castle Cape-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING TUESDAY NIGHT...

.TONIGHT...SE wind 35 kt. Seas 14 ft. Rain and snow.
.TUE...S wind 25 kt. Seas 17 ft. Rain and snow showers.
.TUE NIGHT...NW wind 30 kt. Gusts to 45 kt out of bays and passes.
Seas 18 ft. Heavy freezing spray near the coast.
.WED...NW wind 30 kt. Seas 16 ft.
.WED NIGHT...SW wind 25 kt. Seas 10 ft.
.THU...SW wind 30 kt. Seas 13 ft.
.FRI...SW wind 30 kt. Seas 17 ft.
.SAT...W wind 25 kt. Seas 16 ft.

$$

PKZ155-141330-
South of the AK Peninsula Castle Cape to Cape Sarichef-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TONIGHT...

.TONIGHT...S wind 35 kt. Seas 14 ft building to 19 ft after
midnight. Rain and snow showers.
.TUE...S wind 30 kt shifting to N 35 kt in the afternoon. 
From the Shumagin Islands E, wind becoming NW 25 kt in the 
afternoon. Seas 22 ft. Rain showers.
.TUE NIGHT...NW wind 30 kt. Seas 20 ft. Freezing spray.
.WED AND WED NIGHT...SW wind 30 kt. Seas 11 ft.
.THU THROUGH FRI...SW wind 30 kt. Seas 22 ft.
.SAT...SW wind 25 kt. Seas 15 ft.

$$

PKZ160-141330-
Bristol Bay-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...NE wind 40 kt. Seas in ice free waters 6 ft. 
Heavy freezing spray. Snow.
.TUE...NE wind 30 kt diminishing to 20 kt in the afternoon. 
Seas in ice free waters 5 ft. Heavy freezing spray.
.TUE NIGHT...NW wind 30 kt. Seas in ice free waters 7 ft. 
Heavy freezing spray.
.WED...NW wind 25 kt. Seas in ice free waters 7 ft.
.WED NIGHT...E wind 25 kt. Seas in ice free waters 3 ft.
.THU...SE wind 25 kt. Seas in ice free waters 4 ft.
.FRI THROUGH SAT...SW wind 25 kt. Seas in ice free waters 11 ft.

$$

PKZ165-141330-
Port Heiden to Cape Sarichef-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING TUESDAY NIGHT...

.TONIGHT...SE wind 40 kt becoming S 25 kt after midnight. 
From Port Moller E, E wind 40 kt. Seas 11 ft. Snow and rain.
.TUE...NE wind 30 kt. Seas 11 ft. Freezing spray.
.TUE NIGHT...NW wind 30 kt. Seas 9 ft. Heavy freezing spray.
.WED...E wind 30 kt. Seas 6 ft.
.WED NIGHT...SW wind 30 kt. Seas 6 ft.
.THU...S wind 35 kt. Seas 16 ft.
.FRI...SW wind 30 kt. Seas 21 ft.
.SAT...SW wind 25 kt. Seas 15 ft.

$$

PKZ170-141330-
Cape Sarichef to Nikolski Bering Side-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TUESDAY...

.TONIGHT...S wind 25 kt becoming NE after midnight. Seas 11 ft.
.TUE...N wind 40 kt diminishing to 30 kt in the afternoon. 
Seas 18 ft.
.TUE NIGHT...NW wind 25 kt. Seas 11 ft. Freezing spray.
.WED...SE wind 40 kt. Seas 9 ft.
.WED NIGHT...SW wind 30 kt. Seas 9 ft.
.THU...S wind 40 kt. Seas 24 ft.
.FRI...SW wind 30 kt. Seas 24 ft.
.SAT...SW wind 25 kt. Seas 15 ft.

$$

PKZ171-141330-
Unalaska Bay-
333 PM AKST Mon Feb 13 2023

...SMALL CRAFT ADVISORY TUESDAY AND TUESDAY NIGHT...

.TONIGHT...S wind 15 kt becoming E after midnight. Seas 3 ft. 
Snow showers.
.TUE...NW wind 30 kt. Seas 12 ft. Snow and rain showers.
.TUE NIGHT...NW wind 25 kt becoming W 15 kt after midnight. 
Seas 10 ft subsiding to 5 ft after midnight. Freezing spray 
in the evening.
.WED...SE wind 30 kt. Seas 5 ft.
.WED NIGHT...W wind 25 kt. Seas 4 ft.
.THU...S wind 35 kt. Seas 5 ft.
.FRI...SW wind 20 kt. Seas 3 ft.
.SAT...SW wind 15 kt. Seas 2 ft.

$$

PKZ172-141330-
Cape Sarichef to Nikolski Pacific Side-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TUESDAY...

.TONIGHT...S wind 30 kt. Seas 27 ft. Rain showers.
.TUE...N wind 40 kt. Seas 26 ft.
.TUE NIGHT...NW wind 30 kt. Seas 17 ft subsiding to 11 ft 
after midnight.
.WED...S wind 35 kt. Seas 13 ft.
.WED NIGHT...W wind 30 kt. Seas 16 ft.
.THU...S wind 40 kt. Seas 28 ft.
.FRI...SW wind 25 kt. Seas 26 ft.
.SAT...SW wind 25 kt. Seas 15 ft.

$$

PKZ173-141330-
Nikolski to Seguam Island Bering Side-
333 PM AKST Mon Feb 13 2023

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...E wind 25 kt becoming N 45 kt after midnight. 
Seas 24 ft.
.TUE...N wind 40 kt becoming NW 25 kt in the afternoon. 
Seas 22 ft subsiding to 16 ft in the afternoon.
.TUE NIGHT...N wind 15 kt becoming SE 40 kt after midnight. 
Seas 12 ft. Snow.
.WED...S wind 40 kt. Seas 13 ft.
.WED NIGHT...SW wind 30 kt. Seas 12 ft.
.THU...S wind 35 kt. Seas 26 ft.
.FRI...SW wind 30 kt. Seas 26 ft.
.SAT...S wind 25 kt. Seas 13 ft.

$$

PKZ174-141330-
Nikolski to Seguam Island Pacific Side-
333 PM AKST Mon Feb 13 2023

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...SE wind 30 kt becoming N 40 kt after midnight. 
Seas 29 ft.
.TUE...NW wind 45 kt diminishing to 30 kt in the afternoon. 
Seas 23 ft.
.TUE NIGHT...NW wind 20 kt becoming SE 35 kt after midnight. 
Seas 12 ft. Snow and rain.
.WED...SW wind 40 kt. Seas 16 ft.
.WED NIGHT...SW wind 25 kt. Seas 18 ft.
.THU...S wind 35 kt. Seas 32 ft.
.FRI...SW wind 25 kt. Seas 28 ft.
.SAT...SW wind 25 kt. Seas 16 ft.

$$

PKZ175-141330-
Seguam Island to Adak Bering Side-
333 PM AKST Mon Feb 13 2023

...STORM WARNING TONIGHT...

.TONIGHT...N wind 50 kt. Seas 26 ft. Freezing spray. 
Rain and snow showers.
.TUE...N wind 35 kt becoming NE 20 kt in the afternoon. 
Seas 19 ft. Freezing spray.
.TUE NIGHT...E wind 35 kt becoming SE 45 kt after midnight. 
Seas 14 ft. Snow and rain.
.WED...SW wind 35 kt. Seas 13 ft.
.WED NIGHT...S wind 30 kt. Seas 12 ft.
.THU THROUGH FRI...S wind 30 kt. Seas 22 ft.
.SAT...S wind 25 kt. Seas 11 ft.

$$

PKZ176-141330-
Seguam Island to Adak Pacific Side-
333 PM AKST Mon Feb 13 2023

...GALE WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 45 kt. Seas 28 ft subsiding to 21 ft 
after midnight. Rain showers.
.TUE...NW wind 35 kt becoming N 20 kt in the afternoon. 
Seas 18 ft subsiding to 12 ft in the afternoon.
.TUE NIGHT...SE wind 45 kt. Seas 9 ft building to 16 ft 
after midnight. Rain and snow.
.WED...SW wind 40 kt. Seas 20 ft.
.WED NIGHT...S wind 25 kt. Seas 21 ft.
.THU...S wind 35 kt. Seas 31 ft.
.FRI...S wind 25 kt. Seas 26 ft.
.SAT...S wind 25 kt. Seas 15 ft.

$$

PKZ177-141330-
Adak to Kiska-
333 PM AKST Mon Feb 13 2023

...STORM WARNING TONIGHT AND TUESDAY NIGHT...

.TONIGHT...N wind 50 kt diminishing to 30 kt after midnight. 
Seas 25 ft.
.TUE...NE wind 25 kt becoming E 45 kt in the afternoon. 
Seas 16 ft. Snow.
.TUE NIGHT...SE wind 50 kt. Seas 19 ft. Rain and snow.
.WED AND WED NIGHT...S wind 35 kt. Seas 24 ft.
.THU THROUGH FRI...S wind 30 kt. Seas 23 ft.
.SAT...S wind 30 kt. Seas 16 ft.

$$

PKZ178-141330-
Kiska to Attu-
333 PM AKST Mon Feb 13 2023

...STORM WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...NE wind 30 kt. Seas 17 ft.
.TUE...E wind 50 kt increasing to 60 kt in the afternoon. 
Seas 16 ft building to 25 ft in the afternoon. Snow.
.TUE NIGHT...SE wind 60 kt becoming S 35 kt after midnight. 
Seas 25 ft. Snow and rain.
.WED AND WED NIGHT...S wind 45 kt. Seas 36 ft.
.THU...SW wind 35 kt. Seas 23 ft.
.FRI THROUGH SAT...S wind 30 kt. Seas 19 ft.

$$

PKZ179-141330-
Pribilof Islands Near Shore Waters-
333 PM AKST Mon Feb 13 2023

...GALE WARNING THROUGH TUESDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...NE wind 45 kt. Seas 17 ft. Extreme freezing spray at a rate 
of 4 cm per hour or greater may rapidly accumulate on vessels from
around Saint Paul Island northward. Snow.
.TUE...N wind 35 kt. Seas 15 ft. Heavy freezing spray.
.TUE NIGHT...N wind 20 kt in the evening becoming variable 10 kt.
Seas 8 ft. Heavy freezing spray early.
.WED...E wind 40 kt. Seas 11 ft.
.WED NIGHT...SW wind 35 kt. Seas 12 ft.
.THU...SE wind 30 kt. Seas 21 ft.
.FRI...SW wind 30 kt. Seas 29 ft.
.SAT...S wind 20 kt. Seas 14 ft.

$$

PKZ180-141330-
Kuskokwim Delta and Etolin Strait-
333 PM AKST Mon Feb 13 2023

...GALE WARNING TONIGHT...

.TONIGHT...NE wind 40 kt. 
.TUE...N wind 30 kt. 
.TUE NIGHT...NW wind 30 kt. 
.WED...N wind 20 kt.
.WED NIGHT...E wind 30 kt.
.THU...SE wind 20 kt.
.FRI...S wind 20 kt.
.SAT...SW wind 20 kt.

$$

PKZ181-141330-
North and West of Nunivak Island-
333 PM AKST Mon Feb 13 2023

...BRISK WIND ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 25 kt.
.TUE...N wind 25 kt.
.TUE NIGHT...NW wind 25 kt.
.WED...NE wind 20 kt.
.WED NIGHT...E wind 30 kt.
.THU THROUGH FRI...E wind 20 kt.
.SAT...Variable wind 10 kt.

$$

PKZ185-141330-
Saint Matthew Island Waters-
333 PM AKST Mon Feb 13 2023

...HEAVY FREEZING SPRAY WARNING THROUGH TUESDAY NIGHT...
...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...N wind 25 kt. Seas in ice free waters 6 ft. Extreme 
freezing spray in the afternoon at a rate of 4 cm per hour or 
greater may rapidly accumulate on vessels.
.TUE...N wind 25 kt. Seas in ice free waters 6 ft. Extreme 
freezing spray in the afternoon at a rate of 4 cm per hour or 
greater may rapidly accumulate on vessels.
.TUE NIGHT...E of Saint Matthew Island, NW wind 20 kt. W of Saint 
Matthew Island, N wind 20 kt becoming NE 30 kt after midnight. Seas 
in ice free waters 5 ft. Heavy freezing spray.
.WED...E wind 40 kt. Seas in ice free waters 11 ft.
.WED NIGHT...NE wind 40 kt. Seas in ice free waters 15 ft.
.THU...NE wind 35 kt. Seas in ice free waters 17 ft.
.FRI...NE wind 25 kt. Seas in ice free waters 12 ft.
.SAT...NE wind 20 kt. Seas in ice free waters 8 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
452 PM AKST Sun Feb 12 2023

.ANALYSIS AND UPPER LEVELS...

An upper level long-wave trough continues to dominate most of
western Alaska and the Bering Sea, anchored by a broad upper
level low in the vicinity of St. Lawrence Island. Several short-
waves are rotating around the broad upper low, with one primary
short-wave rotating across Southwest Alaska.

At the surface, a low pressure system is slowly moving east across
the northern Gulf, pushing moisture into Southcentral and Prince
William Sound. A tight pressure gradient has set up across Kodiak
Island to Homer, creating an area of strong westerly winds.

Areas of generally light snow were occurring from the central to
eastern Aleutians, with pockets of light snow occurring in
Southwest AK. Southcentral received light snow with pockets of
freezing drizzle this morning.

&&

.MODEL DISCUSSION...

Deterministic models remain in good agreement with the synoptic
features through Wednesday. The biggest challenge in the near-term
continues to be in Southcentral where small fluctuations in
location and strength of any developing low pressure circulation
along the front can have a significant impact on localized
conditions. At this time, models show a surface low developing
near Kodiak Island by 12z Tuesday. The GFS is showing a much more
defined circulation, which then dissipates with another
circulation developing farther east. The NAM shows a more cohesive
progression of the developing low.

Deterministic models all show a very similar handling of the
strong low pressure system moving across the North Pacific at
the start of the work week. The biggest question there is how
far north will the front make it into the Bering by Monday night.

&&

.AVIATION...

PANC...Precip has changed over to all snow after a period of
mixed precip this morning. Cold air advection along with a deep
layer with the temperature in the dendritic snow growth zone will
lead to periods of moderate snow late this afternoon and evening.
While MVFR conditions may prevail, do expect periods of IFR or
even briefly LIFR in heavier snow. Ceilings will then gradually
lift overnight as the heavier snow shifts eastward toward the
mountains, with VFR conditions likely by morning. Occasional gusty
southwest winds are possible through the evening as cold air
continues to advect into the area.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3/Tonight
through Wednesday)...

An active pattern will gradually quiet down during this forecast
period. Snow will continue across Southcentral Alaska this evening
and tonight. The snow may be heavy at times due to very high snow
to liquid equivalent ratios and a deep dendritic growth layer.
A Winter Weather Advisory has been issued for Anchorage through
5 AM AKST Monday morning due to 4-8" of new snow expected with
locally higher amounts along the hillside, East Anchorage and
Eagle River.

The other big story will be the strong westerly winds across the
waters that encompass the western Gulf of Alaska. Strong cold air
advection associated with these strong winds will result in heavy
to extreme freezing spray. Gusts will reach hurricane force in
spots prone to localized funneling.

The pattern will gradually quiet down from Monday into Tuesday.
Temperatures will become much colder, though no significant
weather is to be expected.

&&

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

The biggest story for the start of the week will center around the
blast of bitterly cold, Arctic air streaming southeast around a
persistent upper level low drifting near the Norton Sound. A bit
of light snow will continue for a few more hours over the Lower
Kuskokwim Valley as an shortwave trough lifts past the region
towards the Interior, but otherwise low level clouds and light
snow will continue to break up through the overnight tonight as
the low levels dry out under a stout shortwave ridge moving in
from the eastern Bering. Diminishing winds and clearing skies will
make for ideal conditions for frigidly cold overnight lows to
materialize, with widespread temperatures bottoming out in the
-10s to -20s through early tomorrow morning. Most of the day on
 Monday will continue to be dominated by mostly clear and cold
 conditions, with highs struggling to break the zero (Fahrenheit)
 mark.

By Monday evening, a notable shift in the pattern will begin as a
strong Bering low pushes its front northeast along the Alaska
Peninsula and into Bristol Bay by Monday night. Snowfall will
begin across much of Bristol Bay from north to south, persisting
into Tuesday as the then weakening low skirts south of Kodiak
Island. As has been the case with our recent frontal systems, the
highest totals will be focused between Dillingham and Koliganek,
where about 4 to 7 inches of new accumulation will be possible
between late Monday and Tuesday afternoon. Snowfall will taper
off between Tuesday evening and Wednesday as the weakening system
shifts out into the Gulf and as another shortwave ridge moves
into place from the Bering.

&&

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

Satellite and scatterometer data are showing an impressively
strong low approaching Hurricane force barreling towards the
central Aleutians from the south this afternoon, with very strong
easterly winds with gusts peaking near 80 mph expected to begin
shortly for Adak and Atka. An Arctic air mass out ahead of the
low's approaching front will allow for the somewhat unusual
combination of high winds, heavy snowfall and blowing snow as
precipitation begins later this evening. A Winter Storm Warning
has been issued for the central Aleutians through early Monday
for the expected combination of high winds, intense snowfall and
blowing snow reducing visibilities to less than half a mile.
Temperatures will warm overnight as the front lifts north,
resulting in a quick changeover to rain as winds also drop off
behind the frontal passage. Hurricane force sustained winds are
meanwhile expected overnight to the west towards Amchitka, but
expect Shemya to stay out of the worst conditions for this system,
with winds peaking in gale force range.

Going into Monday, the low will continue east just off to the
south of the Aleutian Chain as the front lifts north at gale to
storm force towards the Pribilofs. Blizzard conditions will begin
on Monday morning as snowfall and strong east to northeast winds
pick up, with snow and whiteout conditions then persisting for
many hours through Tuesday morning. Gusty north winds in gale
force range will push along the Aleutian Chain into the southern
Alaska Peninsula as the low exits towards the Gulf. Meanwhile, the
next system in this onslaught of intense lows will only just be
getting started farther west.

On Tuesday, another extremely powerful low will rapidly deepen
south of the Kamchatka Peninsula, kicking another storm to perhaps
Hurricane force front into the western Aleutians by Tuesday
afternoon. Temperatures ahead of this front may again be cold
enough for a short window for snow to fall for a few hours before
warmer air transitions falling precipitation to rain, with
accumulating snow also possible as the front progresses towards
the central/eastern Aleutians and Pribilofs heading into Wednesday.
Very strong winds will be possible as the front first enters the
Bering on Tuesday afternoon across the western Aleutians as well,
with southeast gusts pushing 80 mph possible near Shemya early on
Tuesday afternoon as the front moves past. If it still needs to be
said, there is really no end in sight to the active pattern at
this point.

&&

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

At the onset of this forecast period, expect a highly amplified
pattern with the trough axis near the western Aleutians. Expect a
series of strong lows forecast to track across the region. There
is model divergence that increases with time. But there are some
trends. The Gulf of Alaska continues to look active. Out west, a
low near Kamchatka, potentially as deep as 952 mb, pushes a front
into the central and eastern Aleutians on Thursday. The ECMWF and
the Canadian bring the remnants of this front into Southwest AK
on Friday. A new surface low forms south of Adak on Friday. The
GFS is the outlier. With a potentially strong low pressure at the
surface portions of Alaska will receive gusty winds and light to
moderate precipitation. This appears most likely for the Aleutians
but it is becoming more likely for the southern coast as well,
dependent on the eventual storm track. Additionally, expect a
series of shortwaves embedded in the long wave pattern that will
influence the sensible weather.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Warning 187.
         Blizzard Warning 195.
         Winter Weather Advisory 101.
MARINE...Heavy Freezing Spray Warning 121 129 130 131 132 136 137 138
                                      139 141 150 160 179 180 185.
         Hurricane Force Wind Warning 177.
         Storm Warning 120 130 131 175 176 178.
         Gale Warning 119 121 132 136 137 138 139 141 150 155 160 165
                      170 171 172 173 174 179 180.
FIRE WEATHER...NONE.

&&

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