Gale Warning 530, NWS Anchorage, AK

098 
FZAK62 PAFC 172355
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
355 PM AKDT Fri Sep 17 2021

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-181215-
355 PM AKDT Fri Sep 17 2021
.SYNOPSIS FOR CENTRAL BERING SEA...
A 989 mb low at 48N 176E moves to 53N 158W through Sun afternoon. 
Its front crosses the Alaska Peninsula Sat and Sun. High pressure 
moves over the Aleutians and Southern Bering on Sun.

$$

PKZ411-181215-
Bering Sea Offshore West of 180 and East of the International
Dateline-
355 PM AKDT Fri Sep 17 2021

.TONIGHT...NE wind 10 to 25 kt. Seas 3 to 6 ft. Rain.
.SAT...NW wind 10 to 25 kt. Seas 4 to 9 ft.
.SAT NIGHT...NW wind 10 to 20 kt. Seas 4 to 9 ft.
.SUN...W wind 15 kt. Seas 6 ft.
.SUN NIGHT...SW wind up to 15 kt. Seas 5 ft.
.MON...SE wind 10 to 25 kt. Seas 9 to 14 ft.
.TUE...NE wind 30 kt. Seas 13 to 19 ft.
.WED...N wind 25 kt. Seas 8 ft.

$$

PKZ412-181215-
Bering Sea Offshore 171W to 180 and North of 56N-
355 PM AKDT Fri Sep 17 2021

.TONIGHT...E wind 10 to 20 kt. Seas 5 ft.
.SAT...NE wind 10 to 25 kt. Seas 3 to 7 ft.
.SAT NIGHT...N wind 10 to 20 kt. Seas 3 to 8 ft.
.SUN...NW wind up to 15 kt. Seas 4 to 7 ft.
.SUN NIGHT...NW wind up to 15 kt. Seas 4 ft.
.MON...S wind up to 20 kt. Seas 3 to 8 ft.
.TUE...E wind 20 to 30 kt. Seas 9 to 16 ft.
.WED...NE wind 25 kt. Seas 4 to 7 ft.

$$

PKZ413-181215-
Bering Sea Offshore 171W to 180 and South of 56N-
355 PM AKDT Fri Sep 17 2021

...GALE WARNING THROUGH SATURDAY NIGHT...

.TONIGHT...E wind 15 to 30 kt increasing to 25 to 40 kt after
midnight. Seas 6 to 12 ft. Rain.
.SAT...NE wind 25 to 40 kt. Seas 10 to 15 ft. Rain.
.SAT NIGHT...N wind 20 to 35 kt. Seas 9 to 15 ft.
.SUN...NW wind 10 to 25 kt. Seas 6 to 10 ft.
.SUN NIGHT...NW wind up to 15 kt. Seas 4 to 7 ft.
.MON...SE wind 10 to 25 kt. Seas 6 to 11 ft.
.TUE...E wind 25 kt. Seas 9 to 14 ft.
.WED...NE wind 25 kt. Seas 9 ft.

$$

PKZ414-181215-
Bering Sea Offshore East of 171W-
355 PM AKDT Fri Sep 17 2021

...GALE WARNING SATURDAY...

.TONIGHT...N wind up to 15 kt becoming E after midnight. Seas 5
ft.
.SAT...E wind 20 to 35 kt. Seas 6 to 10 ft. Rain.
.SAT NIGHT...NE wind 15 to 30 kt. Seas 6 to 12 ft.
.SUN...N wind 15 to 25 kt. Seas 6 to 10 ft.
.SUN NIGHT...N wind 10 to 25 kt. Seas 4 to 8 ft.
.MON...N wind 10 to 25 kt. Seas 5 to 9 ft.
.TUE THROUGH WED...NE wind 15 to 25 kt. Seas 4 to 9 ft.

$$

144 
FZAK62 PAFC 181142
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
342 AM AKDT Sat Sep 18 2021

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-190100-
342 AM AKDT Sat Sep 18 2021
.SYNOPSIS FOR CENTRAL BERING SEA...

A 988 mb low at 50N 177W moves to 51N 169W at 986 mb Sat evening 
and then exits into the North Pacific Sun morning. Its front 
crosses the Eastern Aleutians through Sun morning. High pressure 
moves over the Bering through Mon morning.

$$

PKZ411-190100-
Bering Sea Offshore West of 180 and East of the International
Dateline-
342 AM AKDT Sat Sep 18 2021

.TODAY...NW wind 10 to 25 kt. Seas 4 to 9 ft.
.TONIGHT...NW wind 10 to 20 kt. Seas 4 to 9 ft.
.SUN...W wind 15 kt. Seas 6 ft.
.SUN NIGHT...SW wind up to 15 kt. Seas 5 ft.
.MON THROUGH WED...E wind 10 to 25 kt. Seas 5 to 10 ft.

$$

PKZ412-190100-
Bering Sea Offshore 171W to 180 and North of 56N-
342 AM AKDT Sat Sep 18 2021

.TODAY...NE wind 10 to 25 kt. Seas 3 to 7 ft.
.TONIGHT...N wind 10 to 20 kt. Seas 3 to 8 ft.
.SUN...NW wind 10 to 15 kt. Seas 6 ft.
.SUN NIGHT...NW wind up to 15 kt. Seas 4 ft.
.MON...S wind up to 15 kt. Seas 3 ft.
.TUE...SE wind 10 to 25 kt. Seas 3 to 6 ft.
.WED...NE wind 10 to 25 kt. Seas 5 to 9 ft.

$$

PKZ413-190100-
Bering Sea Offshore 171W to 180 and South of 56N-
342 AM AKDT Sat Sep 18 2021

...GALE WARNING THROUGH TONIGHT...

.TODAY...NE wind 25 to 40 kt. Seas 8 to 13 ft. Rain.
.TONIGHT...N wind 20 to 35 kt. Seas 9 to 14 ft.
.SUN...NW wind 10 to 25 kt. Seas 7 to 10 ft.
.SUN NIGHT...NW wind up to 15 kt. Seas 4 to 7 ft.
.MON...S wind up to 20 kt. Seas 3 ft.
.TUE THROUGH WED...NE wind 15 to 30 kt. Seas 6 to 11 ft.

$$

PKZ414-190100-
Bering Sea Offshore East of 171W-
342 AM AKDT Sat Sep 18 2021

...GALE WARNING TODAY...

.TODAY...E wind 20 to 35 kt. Seas 4 to 9 ft. Rain.
.TONIGHT...NE wind 15 to 30 kt. Seas 5 to 10 ft.
.SUN...N wind 15 to 25 kt. Seas 4 to 9 ft.
.SUN NIGHT...N wind 10 to 25 kt. Seas 4 to 8 ft.
.MON...NE wind 10 to 25 kt. Seas 3 to 6 ft.
.TUE THROUGH WED...NE wind 15 to 30 kt. Seas 4 to 9 ft.

$$

141 
FZAK62 PAFC 182352
OFFALU

Offshore Waters Forecast
National Weather Service Anchorage AK
352 PM AKDT Sat Sep 18 2021

Offshore Waters Forecast for the Bering Sea

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.

PKZ499-191500-
352 PM AKDT Sat Sep 18 2021
.SYNOPSIS FOR CENTRAL BERING SEA...

A 987 mb low at 51N 170W moves to 52N 158W at 990 mb Sun 
afternoon and then exits into the western Gulf Mon morning. Its 
front crosses the Eastern Aleutians through Sun morning. High 
pressure moves across the western and central Bering and Aleutians 
through Mon afternoon.

$$

PKZ411-191500-
Bering Sea Offshore West of 180 and East of the International
Dateline-
352 PM AKDT Sat Sep 18 2021

.TONIGHT...NW wind 10 to 20 kt. Seas 3 to 8 ft.
.SUN...W wind 15 kt. Seas 6 ft.
.SUN NIGHT...SW wind 10 to 15 kt. Seas 5 ft.
.MON...S wind up to 15 kt. Seas 5 ft.
.MON NIGHT...SE wind up to 20 kt. Seas 4 ft.
.TUE THROUGH WED...E wind 10 to 25 kt. Seas 4 to 9 ft.
.THU...NW wind up to 20 kt. Seas 7 ft.

$$

PKZ412-191500-
Bering Sea Offshore 171W to 180 and North of 56N-
352 PM AKDT Sat Sep 18 2021

.TONIGHT...NW wind 10 to 20 kt. Seas 3 to 8 ft.
.SUN...NW wind 15 kt. Seas 6 ft.
.SUN NIGHT...NW wind up to 15 kt. Seas 5 ft.
.MON...S wind up to 10 kt. Seas 3 ft.
.MON NIGHT...SE wind up to 15 kt. Seas 4 ft.
.TUE...E wind 10 to 25 kt. Seas 3 to 6 ft.
.WED...NE wind 10 to 25 kt. Seas 5 to 9 ft.
.THU...W wind up to 15 kt. Seas 5 ft.

$$

PKZ413-191500-
Bering Sea Offshore 171W to 180 and South of 56N-
352 PM AKDT Sat Sep 18 2021

...GALE WARNING TONIGHT...

.TONIGHT...N wind 20 to 35 kt. Seas 8 to 13 ft.
.SUN...NW wind 10 to 25 kt. Seas 5 to 10 ft.
.SUN NIGHT...NW wind 10 to 15 kt. Seas 6 ft.
.MON...S wind up to 10 kt. Seas 4 ft.
.MON NIGHT...E wind up to 20 kt. Seas 4 ft.
.TUE THROUGH WED...NE wind 15 to 30 kt. Seas 6 to 11 ft.
.THU...NE wind up to 10 kt. Seas 6 ft.

$$

PKZ414-191500-
Bering Sea Offshore East of 171W-
352 PM AKDT Sat Sep 18 2021

.TONIGHT...NE wind 15 to 30 kt. Seas 6 to 11 ft.
.SUN...N wind 15 to 25 kt. Seas 4 to 9 ft.
.SUN NIGHT...N wind 10 to 20 kt. Seas 4 to 7 ft.
.MON...N wind 10 to 25 kt. Seas 4 ft.
.MON NIGHT...NE wind up to 15 kt. Seas 3 to 6 ft.
.TUE THROUGH WED...NE wind 15 to 30 kt. Seas 4 to 9 ft.
.THU...NW wind up to 15 kt. Seas 3 to 6 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
521 PM AKDT Thu Sep 16 2021

.ANALYSIS AND UPPER LEVELS...

An elongated upper-level trough embedded with multiple lows
continues to influence the domain. It is currently extending from
the Bering/Aleutians to the eastern Gulf and continues to slide
east. An upper-level low and associated surface trough are
positioned south of Unalaska and supported by a 180 kt jet
streak. Gale force winds are being reported on the back side of
this system as pressure gradient tightens along the central
Aleutians due to a building ridge to the west. Further east,
radar is showing returns along the eastern side of Cook Inlet,
Prince William Sound, and the Copper River Basin as a result from
a southeasterly, upslope flow and shortwaves spinning off of
another upper-level low southeast of Kodiak. A blanket of low
stratus is extending from the Bering, Aleutians, and into the Gulf
as the trough propagates east. Satellite is showing another area
of clouds moving along the coast and lifting into in the interior
as the associated occluding front moves towards Prince William
Sound. Gale force winds are developing along and ahead of the
front, with strong northeasterly winds also across the Barren
Islands, southern Cook Inlet and through Shelikof Strait.

&&

.MODEL DISCUSSION...

Models continue to be in good agreement when keying in on
impactful synoptic features. A forecast challenge will be how much
clearing we will have over the weekend due to a ridge building
over Southcentral in the wake of the current trough. The amount
of clearing and timing of when/if calmer winds occur will heavily
impact the temperatures as we could have our first potential
outbreak of cold air for the season and a threat for sub-freezing
temperatures at lower elevations over parts of Southcentral and
the interior Southwest by Sunday morning. The more clearing we
have and the calmer the winds, will result in cooler temperatures.
Overall, forecast confidence is high for the short-term, and
average moving into next week.

&&

.AVIATION...

PANC...Mainly VFR conditions and light north winds will persist.
There may be a period or two of MVFR ceilings through the
evening, but the overall trend through tomorrow should be for
slowly improving conditions.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: This
afternoon through Sunday)...

The gale force low continues to move east across the Gulf. Several
shortwaves will rotate around the low and increase winds across
the northern Gulf. The strongest shortwave will form a surface low
this evening and produce storm force winds from between Cape
Suckling and Hinchinbrook Island. This low will rotate south and
east by Friday morning across the western Gulf with Gales expected
off the east coast of the Kenai Peninsula and east of Kodiak
Island. The occluded front associated with the low over the Gulf
will slowly move north across the northern Gulf with moderate to
heavy rain expected from Cordova to Prince William Sound. The rest
of Southcentral remains under cloud cover due to this front,
however very little rain is expected as downsloping will keep much
of the areas west of the Chugach and Coastal Mountains dry. An
occasional sprinkle or light rain shower is possible but
accumulations will be very light. Some light rain will continue
for the Susitna valley due to energy from the weakening low over
the interior of Alaska. This rain should wind down later this
evening.

Friday most areas north of the coast are expected to be dry with
clouds slowly thinning out with a few sunny breaks possible by
afternoon. This will be due to the low moving east across the
Gulf and an Arctic trough moving into Western Alaska. However,
rain will continue along the north Gulf coast and the Chugach
Mountains may see some lingering light rain as the front weakens.
Friday night and Saturday morning the Arctic shortwave will begin
its trek across Southcentral this will usher in stronger
northwesterly gap winds in the usual places. Expect Gales and
possibly storm force winds across Kamishak Bay and the Barren
Islands. Otherwise Seward and Whittier and adjacent marine areas
will see north and westerly winds increase Saturday. This Arctic
shortwave will move through the area by Saturday evening, which
will usher in the coldest air of the season Sunday morning with
low temperatures in the 30s in many locations and 20s possible
especially across the Copper River Basin. Winds will also be gusty
out of the Copper River Delta Saturday afternoon through early
Sunday which may kick up some glacial silt. Otherwise winds will
begin to decrease on Sunday as the pressure gradient weakens and
cold air advection ends. Expect bright sunny skies Saturday
afternoon and Sunday across much of the area as dry and cold air
temporally takes up residence this weekend.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3/Tonight
through Sunday afternoon)...

Clearing skies and colder temperatures are forecast for the
Southwest in the coming days. A shortwave moves through the area
tonight through Friday afternoon. Light rain is possible with the
passage of this shortwave, though it will mostly be limited to the
Kuskokwim Delta coast and higher elevations. From Friday
afternoon through Sunday afternoon, ridging overhead will bring
partly cloudy to clear skies over much of the Southwest. Decreased
cloud cover and the continued advection of cooler air will allow
temperatures to drop near freezing Friday and Saturday night.
While coastal areas will remain in the mid 30s to low 40s, inland
areas in the Kuskokwim Valley will see temperatures in the upper
20s. A North Pacific low approaches on Sunday, leading to
increasing cloud cover and rain chances over Bristol Bay. With the
track of the low remaining to the south, the Kuskokwim Delta and
Lower Kuskokwim Valley will continue to be dry and partly cloudy.

&&

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

Conditions remain cloudy and rainy throughout the Bering and
Aleutians for the next several days. As a ridge moves across the
Chain, gusty northerly winds persist through the Eastern Aleutians
and AKPEN through Saturday afternoon. The strongest winds are
expected over the AKPEN Friday evening as a shortwave moves
overhead. In the Western and Central Aleutians, a low in the North
Pacific brings gusty winds and areas of moderate to heavy
rainfall Friday morning. The low occludes and weakens as it tracks
along the Aleutian Chain through Sunday morning, moving south of
the AKPEN afterwards.

&&

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

Gulf of Alaska... An Aleutian Islands upper low on Sunday will
progress eastward and into the Gulf by Monday. East to southeast
winds gusting to gale force and seas of 10 to 15 ft will accompany
the front's arrival to the Gulf Coast by Monday night. Enhanced
north to northeast winds will follow in the wake of the low, first
impacting the Aleutians Sunday into Monday, and then impacting
the western Gulf Monday into Tuesday. Northwesterly offshore gales
develop Monday night and Tuesday morning across the Barren
Islands, with slightly weaker offshore northerly winds impacting
the locations of Seward and Prince William Sound.

Bering/Aleutians... High pressure remains over the Northern
Bering Sunday into early next week. Across the Southern Bering low
pressure over the Aleutians on Sunday will progress eastward and
into the Gulf of Alaska by Monday. East to northeast gales with
local areas of storm force winds will exist on the backside of the
low. These winds cross the Aleutians over the same time period
and before the low exits the Aleutians to the east. As the
pressure gradient changes and offshore flow develops, winds with
gusts to gale force will exist offshore of the Kuskokwim Delta,
Bristol Bay, and especially for the Eastern Aleutians and Alaska
Peninsula, which are more susceptible to gap winds. Seas to 20 ft
on the Pacific side of the Aleutians and Alaska Peninsula on
Monday.

&&

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

The week begins with a highly amplified upper-level patten
stretching from the Kamchatka Peninsula east to the Canadian
Rockies. The main trough axis is expected to be positioned over
the state, with a potent polar low centered over the North Slope
and a second upper-level low at the base of the trough, over the
central Gulf of Alaska. This feature will support a surface low in
the western Gulf and front extending toward the northern Gulf
with rain along the Southcentral coast.

A strong shortwave is forecast to eject from the polar low and
dive south, phasing with the Gulf low by Tuesday morning. This is
in conjunction with the polar jet also digging south and phasing
with the subtropical jet. While guidance is all showing this
solution, there is some uncertainty as to where (AKPen and
western Gulf or farther east) this phasing may take place. The
result, however, will be the potential for a surge of arctic air
over the Southern Mainland overnight Monday through early
Wednesday with very strong northerly and westerly gap winds along
coastal locations as a surface ridge builds over the interior and
a secondary surface low develops and rapidly deepens over the
northern Gulf. 850 mb temperatures (~4,500 ft AGL) could drop as
low as -5C to -10C across parts of interior Southwest and
Southcentral by Tuesday, with any lingering precipitation behind
the cold air advection turning to snow over the mountains. The 12z
GFS and GEM are also hinting that enough cold air may work into
the Copper River Basin by Tuesday that lingering rain could change
to snow at lower elevations before ending. Clear and colder
conditions then look to prevail mid-week as the trough moves east
and an upper-level ridge builds.

Father west, the upper-level ridge over the Bering for the start
of the week moves east toward the Mainland as another potential
storm-force low moves from south of Attu east across Chain to a
position south of the AKPen by Thursday. Expect northerly gap
winds across the eastern Aleutians and AKPen Monday, tapering off
Tuesday as the ridge crests overhead. Easterly gales and rain are
then likely across the Chain from west to east Tuesday through
early Thursday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Storm 119 130
		 Gale 120 131 132 138 139 150 155.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...TM
SOUTHCENTRAL ALASKA...RC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KC
MARINE/LONG TERM...BL