Storm Warning 51, NWS Anchorage, AK

305 
FZAK52 PAFC 281226
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
326 AM AKST Fri Feb 28 2020

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.

PKZ199-290130-
326 AM AKST Fri Feb 28 2020
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 985 mb low at 385 nm SE of Shemya Fri morning moves to 230 nm 
NE of Shemya at 979 mb Sat morning, then moves to 80 nm NW of 
Shemya at 986 mb Sun morning. Another north Pacific low 235 nm S
of Adak at 974 mb Sat morning moves to 60 nm SW of Cape Newenham 
at 972 mb Sun morning. A pair of fronts moves through the central
Aleutians and AKPEN into the Bering Sat through Sun.

$$

PKZ150-290130-
South of the AK Peninsula Sitkinak to Castle Cape-
326 AM AKST Fri Feb 28 2020

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

.TODAY...NW wind 25 kt. Seas 9 ft. Heavy freezing spray along the
coast near the entrance to Shelikof Straight.
.TONIGHT...SW wind 15 kt becoming S 25 kt after midnight. Seas 9
ft.
.SAT...SW wind 35 kt. Seas 13 ft. Rain and snow.
.SAT NIGHT...SW wind 30 kt. Seas 16 ft.
.SUN...W wind 35 kt. Seas 18 ft.
.MON...W wind 25 kt. Seas 17 ft.
.TUE...NW wind 20 kt. Seas 11 ft.

$$

PKZ155-290130-
South of the AK Peninsula Castle Cape to Cape Sarichef-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TONIGHT AND SATURDAY...

.TODAY...SE wind 20 kt in the afternoon. Variable wind 10 kt in
the morning. From the Shumagin Islands E, variable 10 kt. Seas 11 
ft.
.TONIGHT...SE wind 35 kt. From the Shumagin Islands E, SE wind 20
kt increasing to 30 kt after midnight. Seas 11 ft. Rain.
.SAT...S wind 35 kt. Seas 17 ft.
.SAT NIGHT...SW wind 30 kt. Seas 17 ft.
.SUN...SW wind 30 kt. Seas 17 ft.
.MON...W wind 25 kt. Seas 17 ft.
.TUE...N wind 20 kt. Seas 11 ft.

$$

PKZ160-290130-
Bristol Bay-
326 AM AKST Fri Feb 28 2020

...BRISK WIND ADVISORY TONIGHT AND SATURDAY...

.TODAY...Variable wind less than 10 kt becoming E 10 kt in the
afternoon.
.TONIGHT...E wind 15 kt increasing to 25 kt after midnight.
.SAT...E wind 30 kt. Snow and rain.
.SAT NIGHT...SW wind 20 kt.
.SUN...SW wind 30 kt.
.MON...W wind 15 kt.
.TUE...N wind 20 kt.

$$

PKZ165-290130-
Port Heiden to Cape Sarichef-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TONIGHT...
...HEAVY FREEZING SPRAY WARNING TONIGHT...

.TODAY...Variable wind 10 kt becoming SE 20 kt in the afternoon.
Seas 3 ft.
.TONIGHT...SE wind 35 kt. Seas 6 ft. Heavy freezing spray near the
ice edge. Snow and rain.
.SAT...SE wind 25 kt. Seas 6 ft. Snow.
.SAT NIGHT...SW wind 25 kt. Seas 7 ft.
.SUN...SW wind 30 kt. Seas 13 ft.
.MON...W wind 15 kt. Seas 9 ft.
.TUE...N wind 25 kt. Seas 9 ft.

$$

PKZ170-290130-
Cape Sarichef to Nikolski Bering Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING THROUGH TONIGHT...

.TODAY...SE wind 20 kt increasing to 35 kt in the afternoon. Seas
7 ft.
.TONIGHT...SE wind 40 kt diminishing to 30 kt after midnight. Seas
10 ft. Rain and snow.
.SAT...S wind 25 kt. Seas 9 ft. Rain.
.SAT NIGHT...SW wind 30 kt. Seas 12 ft.
.SUN...SW wind 30 kt. Seas 15 ft.
.MON...W wind 20 kt. Seas 10 ft.
.TUE...N wind 25 kt. Seas 9 ft.

$$

PKZ171-290130-
Unalaska Bay-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TONIGHT...

.TODAY...SE wind 15 kt increasing to 25 kt in the afternoon. Seas
2 ft building to 4 ft in the afternoon. Snow and rain.
.TONIGHT...SE wind 35 kt becoming S 20 kt after midnight. Seas 5
ft subsiding to 3 ft after midnight. Rain and snow.
.SAT...S wind 15 kt. Seas 2 ft. Rain.
.SAT NIGHT...SW wind 20 kt. Seas 3 ft.
.SUN...SW wind 25 kt. Seas 4 ft.
.MON...SW wind 15 kt. Seas 3 ft.
.TUE...N wind 20 kt. Seas 7 ft.

$$

PKZ172-290130-
Cape Sarichef to Nikolski Pacific Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING THROUGH SATURDAY...

.TODAY...SE wind 20 kt increasing to 35 kt in the afternoon. Seas
11 ft.
.TONIGHT...SE wind 35 kt. Seas 12 ft. Rain.
.SAT...S wind 35 kt. Seas 21 ft. Rain.
.SAT NIGHT...SW wind 30 kt. Seas 18 ft.
.SUN...SW wind 30 kt. Seas 17 ft.
.MON...SW wind 25 kt. Seas 17 ft.
.TUE...N wind 20 kt. Seas 14 ft.

$$

PKZ173-290130-
Nikolski to Seguam Island Bering Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING THROUGH TONIGHT...

.TODAY...SE wind 30 kt increasing to 45 kt in the afternoon. Seas
6 ft building to 14 ft in the afternoon. Rain.
.TONIGHT...SE wind 40 kt becoming S 20 kt after midnight. Seas 13
ft subsiding to 8 ft after midnight.
.SAT...SW wind 20 kt increasing to 30 kt in the afternoon. Seas 7
ft building to 14 ft in the afternoon.
.SAT NIGHT...SW wind 40 kt. Seas 15 ft.
.SUN...SW wind 35 kt. Seas 17 ft.
.MON...W wind 20 kt. Seas 11 ft.
.TUE...N wind 20 kt. Seas 10 ft.

$$

PKZ174-290130-
Nikolski to Seguam Island Pacific Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TODAY...

.TODAY...SE wind 30 kt increasing to 40 kt in the afternoon. Seas
13 ft. Rain.
.TONIGHT...S wind 25 kt. Seas 11 ft. Rain.
.SAT...SW wind 30 kt. Seas 15 ft building to 21 ft in the
afternoon.
.SAT NIGHT...SW wind 35 kt. Seas 18 ft.
.SUN...SW wind 30 kt. Seas 18 ft.
.MON...SW wind 25 kt. Seas 16 ft.
.TUE...N wind 20 kt. Seas 13 ft.

$$

PKZ175-290130-
Seguam Island to Adak Bering Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TODAY AND SATURDAY...

.TODAY...SE wind 45 kt. Seas 9 ft building to 14 ft in the
afternoon. Rain.
.TONIGHT...S wind 30 kt becoming SW 20 kt after midnight. Seas
12 ft.
.SAT...SW wind 30 kt increasing to 40 kt in the afternoon. Seas
11 ft.
.SAT NIGHT...SW wind 45 kt. Seas 17 ft.
.SUN...SW wind 35 kt. Seas 17 ft.
.MON...NW wind 20 kt. Seas 11 ft.
.TUE...N wind 15 kt. Seas 8 ft.

$$

PKZ176-290130-
Seguam Island to Adak Pacific Side-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TODAY AND SATURDAY...

.TODAY...E wind 40 kt. Seas 14 ft. Rain with snow.
.TONIGHT...SW wind 25 kt. Seas 11 ft.
.SAT...W wind 30 kt becoming SW 40 kt in the afternoon. Seas 14 ft
building to 19 ft in the afternoon.
.SAT NIGHT...SW wind 45 kt. Seas 21 ft.
.SUN...SW wind 35 kt. Seas 20 ft.
.MON...W wind 25 kt. Seas 16 ft.
.TUE...NW wind 20 kt. Seas 11 ft.

$$

PKZ177-290130-
Adak to Kiska-
326 AM AKST Fri Feb 28 2020

...GALE WARNING THROUGH SATURDAY...

.TODAY...E wind 45 kt becoming S in the afternoon. Seas 14 ft.
Rain and widespread snow showers.
.TONIGHT...SW wind 35 kt. Seas 13 ft.
.SAT...SW wind 45 kt. Seas 13 ft.
.SAT NIGHT...SW wind 45 kt. Seas 20 ft.
.SUN...SW wind 35 kt. Seas 19 ft.
.MON...NW wind 25 kt. Seas 17 ft.
.TUE...NW wind 15 kt. Seas 9 ft.

$$

PKZ178-290130-
Kiska to Attu-
326 AM AKST Fri Feb 28 2020

...GALE WARNING SATURDAY...

.TODAY...NE wind 30 kt. Seas 11 ft. Widespread snow and rain
showers.
.TONIGHT...N wind 25 kt. Seas 12 ft. Snow showers and rain
showers.
.SAT...NW wind 35 kt. Seas 20 ft Bering side... 13 ft Pacific side.
Snow showers and rain showers.
.SAT NIGHT...NW wind 35 kt. Seas 23 ft.
.SUN...NW wind 35 kt. Seas 23 ft.
.MON...NW wind 25 kt. Seas 16 ft.
.TUE...NW wind 20 kt. Seas 10 ft.

$$

PKZ179-290130-
Pribilof Islands Near Shore Waters-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TONIGHT...

.TODAY...E wind 15 kt increasing to 25 kt in the afternoon. Seas
5 ft.
.TONIGHT...E wind 35 kt. Seas 12 ft. Snow.
.SAT...SE wind 25 kt. Seas 10 ft.
.SAT NIGHT...SW wind 30 kt. Seas 13 ft.
.SUN...SW wind 25 kt. Seas 14 ft.
.MON...N wind 20 kt. Seas 11 ft.
.TUE...N wind 20 kt. Seas 7 ft.

$$

PKZ180-290130-
Kuskokwim Delta and Etolin Strait-
326 AM AKST Fri Feb 28 2020

...BRISK WIND ADVISORY TONIGHT AND SATURDAY...

.TODAY...N wind 10 kt becoming E in the afternoon.
.TONIGHT...E wind 20 kt increasing to 30 kt after midnight.  Snow
showers.
.SAT...E wind 30 kt. Snow.
.SAT NIGHT...S wind 25 kt.
.SUN...W wind 25 kt.
.MON THROUGH TUE...N wind 20 kt.

$$

PKZ181-290130-
North and West of Nunivak Island-
326 AM AKST Fri Feb 28 2020

...BRISK WIND ADVISORY TONIGHT AND SATURDAY...

.TODAY...Variable wind 10 kt becoming E 15 kt in the afternoon.
.TONIGHT...E wind 25 kt.
.SAT...E wind 30 kt.
.SAT NIGHT...NE wind 25 kt.
.SUN THROUGH TUE...N wind 15 kt.

$$

PKZ185-290130-
Saint Matthew Island Waters-
326 AM AKST Fri Feb 28 2020

...GALE WARNING TONIGHT AND SATURDAY...
...HEAVY FREEZING SPRAY WARNING THROUGH SATURDAY...

.TODAY...E of Saint Matthew Island, variable wind 10 kt becoming E
20 kt in the afternoon. W of Saint Matthew Island, E wind 25 kt.
Seas in ice free waters 5 ft. Heavy freezing spray.
.TONIGHT...E of Saint Matthew Island, E wind 25 kt. W of Saint
Matthew Island, NE wind 30 kt increasing to 40 kt after midnight.
Seas in ice free waters 9 ft. Heavy freezing spray.
.SAT...E wind 30 kt E of Saint Matthew Island...NE 45 kt W of
Saint Matthew Island. Seas in ice free waters 14 ft. Heavy freezing 
spray. Snow showers.
.SAT NIGHT...NE wind 40 kt. Seas in ice free waters 16 ft.
.SUN...NE wind 35 kt. Seas in ice free waters 13 ft.
.MON...N wind 25 kt. Seas in ice free waters 10 ft.
.TUE...NE wind 15 kt. Seas in ice free waters 5 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
410 AM AKST Thu Feb 27 2020

.ANALYSIS AND UPPER LEVELS...

An area of high pressure at the surface and aloft continues to
remain centered over eastern Siberia, while extending into western
Alaska. To it's south, a pair of lows in the Gulf continue to
bring precipitation to portions of the Gulf Coast, mainly from
Prince William Sound to Yakutat.

Further west, a pair of lows was influencing the weather. The
first system was riding the Aleutians in an eastward trek, with
the low currently near Nikolski. Another low just north of Shemya.
Both of these systems were bringing some isolated showery type
precipitation to the region.

&&

.MODEL DISCUSSION...

The models remain in good agreement through the weekend in the
overall synoptic pattern, with the biggest difference being
related to a north Pacific low that moves into the western Bering
Sea saturday morning. Here, the GFS continues to be the strongest
solution (like it has been most of the winter), as it portrays a
964 mb low. Conversely, the ECMWF (European) model is almost 10 mb
weaker, with the Canadian in between in strength but shows two
different low centers in that vicinity. The net difference here is
how much coverage of storm force sustained winds there will be.

They (the numerical models) do show good agreement that a
disturbance aloft will pinch off from this system and eject
eastward, with cyclogenesis (the development of a low pressure
system) commencing in the Gulf by Sunday morning, but once again
they disagree on the strength of the system by 10 mb. This
scenario then repeats itself by early next week. So in short, an
active pattern looks to return to southcentral and southwestern
Alaska, westward through the Aleutians and portions of the Bering
Sea.

&&

.AVIATION...

PANC...VFR conditions and light winds will prevail through the
forecast period.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...

High pressure building in from the northwest is clearing out skies
over Southcentral Alaska. A weak low near Middleton Island is
still pushing a few clouds along the north Gulf coast with a line
of showers toward Cordova early this morning. This area of
showers and clouds should diminish today as the low pushes to the
Southeast and away from the area. This should leave mostly clear
and cold conditions across most of Southcentral through Friday
night.

Friday night is when the next system makes its way to Kodiak
Island from the Southwest and then into the remainder of
Southcentral Saturday. This is the system that is expected to
bring widespread snowfall to Southcentral, with the exception of
Kodiak which will warm up rapidly to turn precipitation type to
rain. The development of a triple point low near the Barren
Islands on Saturday will keep the warmer air from pushing farther
northward keeping precipitation all snow for the rest of
Southcentral.

&&

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

In the past 24 hrs, the temperatures at Bethel and Aniak have
plummeted by more than 10 degrees. The models continue to show
northerly flow in the boundary layer thereby ushering arctic air
into the region. The models look bone dry for Southwest for today
and Friday. A new storm is churning up in the north Pacific and
the leading edge of the precipitation shield will be in Bristol
Bay and Toksook Bay Saturday morning.

&&

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

There is an elongated surface low from Unalaska to the Western
Bering that will continue to weaken and become absorbed into the
longwave pattern on Friday. A developing low will come charging
out of the north Pacific toward the Western Aleutians. The models
continue to show slightly different tracks and intensities with
the surface low but there is high confidence that the Western and
Central Aleutians will see high end gale force winds and rough
seas. A Winter Storm Watch is in effect from Friday afternoon
through Saturday afternoon for Shemya and Amchitka. This storm is
projected to impact the entire chain.

&&

.MARINE (Days 3 through 5 Sat through Mon)...

A strong low in the Bering on Saturday will bring widespread gale
force winds across the Bering, Aleutians, and westward to near
Kodiak Island. Storm force winds are expected closer to the low
center, over the western Bering and central/western Aleutians. By
Sunday this system will weaken, with gales confined to the
central/western Aleutians and the western Bering. For the Gulf, on
Sunday and Monday westerly winds will be near gale force.

&&

.LONG TERM FORECAST (Days 4 through 7 Sun through Wed)...

On Sunday there will be a low in the Bering, with a trough
extending northeast into northern Alaska. Southwesterly flow aloft
will be over all of southern Alaska, extending westward through
the eastern and central Aleutians. Through Monday the models are
in fairly good agreement that the Bering low will weaken and
slowly drift south, while the northern Alaska trough drops
southward into southern Alaska. By Tuesday the deterministic
models diverge significantly on where the Bering low goes, and
also on how the upper level pattern develops over Alaska in
general. Therefore for Tuesday and Wednesday ensemble mean
forecasts are preferred, and forecast confidence is somewhat low.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Storm Watch 191
MARINE...Gale Warning 173 174 175 176 177 178 411 413
         Heavy Freezing Spray warning 129 130 185 414

FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...PD
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PJS
MARINE/LONG TERM...BL