Storm Warning 81, NWS Anchorage, AK

202 
FZAK61 PAFC 300005
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
405 PM AKDT Tue Sep 29 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-301400-
405 PM AKDT Tue Sep 29 2020

.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 967 mb North Pacific low crosses the Alaska Peninsula by Thu 
morning. Its well-developed front spreads over the Gulf through 
Thu afternoon.

$$

PKZ351-301400-
Gulf of Alaska Offshore North of 57N and West of 144W-
405 PM AKDT Tue Sep 29 2020

...STORM WARNING TONIGHT...

.TONIGHT...E wind 40 to 55 kt becoming SE 30 to 40 kt after
midnight. Seas 17 to 24 ft. Rain.
.WED...SE wind 25 to 40 kt becoming 35 kt in the afternoon. Seas
16 to 20 ft.
.WED NIGHT...S wind 35 kt diminishing to 20 to 30 kt after
midnight. Seas 17 to 21 ft.
.THU...SE wind 20 to 30 kt. Seas 13 to 19 ft.
.THU NIGHT...E wind 30 to 40 kt. Seas 13 to 19 ft.
.FRI...S wind 25 to 40 kt. Seas 18 to 26 ft.
.SAT...SE wind 20 to 35 kt. Seas 12 to 16 ft.
.SUN...SW wind 30 kt. Seas 19 to 29 ft.

$$

PKZ352-301400-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
405 PM AKDT Tue Sep 29 2020

...STORM WARNING TONIGHT...

.TONIGHT...SE wind 35 to 50 kt diminishing to 25 to 35 kt after 
midnight. Seas 16 to 23 ft. Rain.
.WED...SE wind 25 to 40 kt. Seas 17 to 21 ft. Rain showers.
.WED NIGHT...S wind 25 to 40 kt becoming 30 kt after midnight.
Seas 17 to 22 ft.
.THU...SE wind 25 to 35 kt. Seas 13 to 17 ft.
.THU NIGHT...SE wind 30 to 45 kt. Seas 14 to 22 ft.
.FRI...S wind 25 to 40 kt. Seas 17 to 28 ft.
.SAT...S wind 20 to 35 kt. Seas 12 to 19 ft.
.SUN...SW wind 25 to 35 kt. Seas 20 to 32 ft.

$$

339 
FZAK61 PAFC 301123
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
323 AM AKDT Wed Sep 30 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-010145-
323 AM AKDT Wed Sep 30 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 970 mb low at 54N 154W Wed morning crosses the AKPEN Thu 
morning. A new low moves to 55N 154W at 967 mb Fri morning. 

$$

PKZ351-010145-
Gulf of Alaska Offshore North of 57N and West of 144W-
323 AM AKDT Wed Sep 30 2020

...GALE WARNING THROUGH THURSDAY...

.TODAY...SE wind 30 to 40 kt. Seas 17 to 21 ft.
.TONIGHT...S wind 20 to 35 kt. Seas 17 to 21 ft.
.THU...SE wind 20 to 30 kt becoming E 25 to 40 kt in the
afternoon. Seas 13 to 16 ft.
.THU NIGHT...E wind 40 to 55 kt. Seas 20 to 28 ft.
.FRI...S wind 25 to 40 kt. Seas 17 to 24 ft.
.SAT...S wind 20 to 30 kt. Seas 12 to 17 ft.
.SUN...SW wind 30 to 45 kt. Seas 17 to 29 ft.

$$

PKZ352-010145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
323 AM AKDT Wed Sep 30 2020

...STORM WARNING THURSDAY...

.TODAY...SE wind 25 to 40 kt. Seas 17 to 23 ft. Rain showers.
.TONIGHT...S wind 25 to 40 kt. Seas 16 to 22 ft.
.THU...SE wind 25 to 35 kt becoming E 35 to 50 kt in the
afternoon. Seas 16 to 24 ft. Rain.
.THU NIGHT...SE wind 35 to 50 kt. Seas 18 to 29 ft.
.FRI...S wind 30 to 45 kt. Seas 16 to 25 ft.
.SAT...S wind 20 to 35 kt. Seas 14 to 17 ft.
.SUN...SW wind 30 to 45 kt. Seas 20 to 28 ft.

$$

873 
FZAK61 PAFC 302219
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
Issued by National Weather Service Juneau AK
219 PM AKDT Wed Sep 30 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-011230-
219 PM AKDT Wed Sep 30 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 975 mb low offshore of Chignik crosses the Alaska Peninsula into
Bristol Bay Wed evening and weakens as it reaches Nunivak Island
Thu. A new low deepens to 968 mb as it approaches Kodiak Island 
from the S Thu night and reaches Dillingham Fri. 

$$

PKZ351-011230-
Gulf of Alaska Offshore North of 57N and West of 144W-
219 PM AKDT Wed Sep 30 2020

...STORM WARNING THURSDAY NIGHT...

.TONIGHT...S wind 20 to 35 kt. Seas 17 to 21 ft.
.THU...SE wind 20 to 30 kt becoming E 25 to 40 kt in the
afternoon. Seas 13 to 16 ft.
.THU NIGHT...E wind 40 to 55 kt. Seas 15 to 23 ft. Rain.
.FRI...S wind 30 to 45 kt. Seas 20 to 30 ft.
.FRI NIGHT...S wind 15 to 30 kt. Seas 17 to 23 ft.
.SAT...S wind 20 to 30 kt. Seas 12 to 17 ft.
.SUN...SW wind 30 to 45 kt. Seas 17 to 29 ft.
.MON...SW wind 20 to 30 kt. Seas 12 to 20 ft.

$$

PKZ352-011230-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
219 PM AKDT Wed Sep 30 2020

...STORM WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...S wind 25 to 40 kt. Seas 16 to 22 ft.
.THU...SE wind 25 to 35 kt becoming E 35 to 50 kt in the
afternoon. Seas 13 to 20 ft. Rain.
.THU NIGHT...SE wind 35 to 50 kt. Seas 17 to 30 ft.
.FRI...S wind 30 to 45 kt. Seas 21 to 32 ft.
.FRI NIGHT...S wind 15 to 30 kt. Seas 15 to 23 ft.
.SAT...S wind 20 to 35 kt. Seas 14 to 17 ft.
.SUN...SW wind 30 to 45 kt. Seas 20 to 28 ft.
.MON...SW wind 20 to 30 kt. Seas 11 to 18 ft.

$$

846 
FZAK61 PAFC 011146
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
346 AM AKDT Thu Oct 1 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-020145-
346 AM AKDT Thu Oct 1 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 970 mb low at 54N 153W Thu evening moves to 56N 153W at 970 mb 
by Thu night. The low continues to 58N 155W at 975 mb by Fri 
morning. The low then moves inland while slowly weakening.

$$

PKZ351-020145-
Gulf of Alaska Offshore North of 57N and West of 144W-
346 AM AKDT Thu Oct 1 2020

...STORM WARNING TONIGHT AND FRIDAY...

.TODAY...SE wind 20 to 30 kt becoming E 25 to 40 kt in the
afternoon. Seas 16 ft.
.TONIGHT...E wind 40 to 55 kt. Seas 18 to 28 ft.
.FRI...SE wind 40 to 50 kt becoming S 25 to 40 kt in the
afternoon. Seas 21 to 28 ft.
.FRI NIGHT...S wind 15 to 30 kt. Seas 16 to 23 ft.
.SAT...S wind 15 to 30 kt. Seas 11 to 16 ft.
.SUN THROUGH MON...SW wind 25 to 40 kt. Seas 10 to 18 ft.

$$

PKZ352-020145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
346 AM AKDT Thu Oct 1 2020

...STORM WARNING THROUGH FRIDAY...

.TODAY...SE wind 25 to 35 kt becoming E 35 to 50 kt in the
afternoon. Seas 13 to 20 ft. Rain.
.TONIGHT...SE wind 35 to 50 kt. Seas 17 to 29 ft.
.FRI...S wind 35 to 50 kt diminishing to 25 to 40 kt in the
afternoon. Seas 21 to 30 ft.
.FRI NIGHT...S wind 25 kt. Seas 15 to 21 ft.
.SAT...S wind 15 to 30 kt. Seas 11 to 16 ft.
.SUN THROUGH MON...SW wind 20 to 35 kt. Seas 11 to 18 ft.

$$

520 
FZAK61 PAFC 020002
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
402 PM AKDT Thu Oct 1 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-021315-
402 PM AKDT Thu Oct 1 2020

.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 970 mb North Pacific low moves to 56N 153W at 972 mb Fri morning. 
The low moves into Bristol Bay and then heads inland Friday afternoon
while slowly weakening. 

$$

PKZ351-021315-
Gulf of Alaska Offshore North of 57N and West of 144W-
402 PM AKDT Thu Oct 1 2020

...STORM WARNING THROUGH FRIDAY...

.TONIGHT...E wind 40 to 55 kt. Seas 13 to 20 ft building to 19 to
27 ft after midnight. Rain.
.FRI...SE wind 35 to 50 kt becoming S 30 to 40 kt in the afternoon. 
Seas 21 to 28 ft. Rain.
.FRI NIGHT...S wind 15 to 30 kt. Seas 15 to 23 ft.
.SAT...S wind 15 to 25 kt. Seas 10 to 15 ft.
.SAT NIGHT...SE wind 15 to 30 kt. Seas 10 ft.
.SUN THROUGH MON...SW wind 25 to 40 kt. Seas 11 to 19 ft.
.TUE...SW wind 10 to 20 kt. Seas 7 to 10 ft.

$$

PKZ352-021315-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
402 PM AKDT Thu Oct 1 2020

...STORM WARNING THROUGH FRIDAY...

.TONIGHT...SE wind 35 to 50 kt. Seas 16 to 29 ft. Rain.
.FRI...S wind 35 to 50 kt diminishing to 25 to 35 kt in the afternoon.
Seas 20 to 30 ft.
.FRI NIGHT...S wind 20 to 30 kt. Seas 13 to 21 ft.
.SAT...S wind 15 to 25 kt. Seas 10 to 14 ft.
.SAT NIGHT...SE wind 20 to 35 kt. Seas 9 to 13 ft.
.SUN THROUGH MON...SW wind 20 to 35 kt. Seas 12 to 20 ft.
.TUE...W wind 10 to 20 kt. Seas 7 to 10 ft.

$$

522 
FZAK61 PAFC 021122
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
322 AM AKDT Fri Oct 2 2020

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-030045-
322 AM AKDT Fri Oct 2 2020
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 971 mb low at 55N 152W moves northwestward into Bristol Bay and
then inland Friday afternoon while slowly weakening. A front 
associated with a North Pacific low approaches the western Gulf 
Sat afternoon. The front pushes across the Gulf through Sat night.

$$

PKZ351-030045-
Gulf of Alaska Offshore North of 57N and West of 144W-
322 AM AKDT Fri Oct 2 2020

...GALE WARNING TODAY...

.TODAY...S wind 30 to 45 kt. Seas 19 to 27 ft. Rain.
.TONIGHT...S wind 15 to 30 kt. Seas 16 to 24 ft.
.SAT...S wind 15 to 25 kt. Seas 12 to 15 ft.
.SAT NIGHT...SE wind 20 to 35 kt. Seas 10 ft.
.SUN...S wind 25 to 40 kt. Seas 13 to 21 ft.
.MON...SW wind 25 to 40 kt. Seas 14 to 22 ft.
.TUE...SW wind 10 to 20 kt. Seas 8 ft.

$$

PKZ352-030045-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
322 AM AKDT Fri Oct 2 2020

...GALE WARNING TODAY...

.TODAY...S wind 30 to 45 kt. Seas 21 to 29 ft.
.TONIGHT...S wind 20 to 30 kt. Seas 14 to 22 ft.
.SAT...S wind 15 to 25 kt. Seas 12 ft.
.SAT NIGHT...SE wind 20 to 35 kt. Seas 10 to 13 ft.
.SUN THROUGH MON...SW wind 25 to 40 kt. Seas 14 to 22 ft.
.TUE...W wind 20 kt. Seas 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
502 PM AKDT Mon Sep 28 2020

.ANALYSIS AND UPPER LEVELS...
The remnants of the strong low that moved through the Gulf of
Alaska is elongating over Southcentral Alaska and into Bristol Bay
this afternoon bringing in some rain to a bit of the region. Some
pressure rises behind this low are bringing in some gusty
southerly winds into Prince William Sound and the Copper River
Basin.

The GOES-17 Satellite imagery for the North Pacific shows the
upper level longwave trough extending southward from the central
Bering Sea to about 35N in the Pacific and then curving sharply
around the base of the trough and back into Southeast Alaska. The
next low of significance can also be seen rapidly spinning-up
around 42N 160W this afternoon. This will be the next in a series
of lows to move into the western Gulf of Alaska.

&&

.MODEL DISCUSSION...
Models remain in good agreement through mid week. By Wednesday
evening there is a notable difference in how fast models bring the
low from south of the Gulf into Bristol Bay around that time
frame. The ECMWF and Canadian are the fastest of the bunch while
the NAM is a bit slower and also stronger at that time. This
mostly resolves itself as the next low moves into the Gulf Friday
and absorbs the energy causing that first low to dissipate in the
central Bering Sea. In the longer term, models are in agreement
with bringing the parade of lows moving moving from the North
Pacific into the Gulf going through the weekend.

&&

.AVIATION...
PANC...Gusty Southeasterly winds out of Turnagain Arm are expected
this evening through most of the overnight hours. While there will
be some light rain at times in the area, these winds should help
keep ceilings VFR, although a period of MVFR ceilings is possible
early this evening in conjunction with the rain. Visibility
should also remain VFR.

&&

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

The cloud remnants from the low pressure system from yesterday are
still making their way across the Gulf of Alaska, Copper River
Basin, Prince William Sound, Kenai and across Anchorage this
evening. Weather observations from across much of the coastal area
indicated steady light to moderate rain, and this should continue
through tonight before rainfall dissipates by early Tuesday
morning. However, western Kenai and Kodiak are expected to stay
dry tonight before the next round of rainfall approaches these
respective locations Tuesday and Tuesday night.

The next major circulation from the North Pacific is still
trekking toward the western Gulf, which will skirt right along the
south-southwest of Kodiak in the next couple days. A broad upper
level ridge settling east-northeast of this deepening low will
continue to build northwestward, and this will force the low
pressure system to steer westward and away from the Gulf in the
days ahead. A strong frontal boundary associated with the expected
storm will dump a lot of rainfall over much of Southcentral Alaska
through the middle of the week. Also, the onset of this next
frontal zone will elevate winds and hazardous wave heights through
the forecast period. Very strong and gusty winds will be felt over
populated areas especially near passes and gaps, and over the
Gulf, including Kodiak, between Tuesday and Wednesday. Overall,
an extensive period of moderate to heavy rainfall is expected, and
this will be closely monitored the next few days.

&&

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

A broad upper level trough lifting northward from the Gulf across
Southwest Alaska tonight will produce just a few showers. Attention
will quickly shift to a much more significant feature. A storm
force low pushes towards the Southern Gulf tonight through Tuesday
before quickly curving northwest towards Bristol Bay. This system
becomes occluded early on, but will remain deep and cause significant
winds and waves as the leading front reaches the Alaska Peninsula
and Bristol Bay Tuesday through Tuesday night. Gusty northeasterly
flow will develop across all of Southwest Alaska Tuesday night
and Wednesday, though the winds over the marine areas will be the
strongest. Additionally, a band of light to moderate rainfall out
ahead of the front will push across the Southwest beginning
Wednesday followed by a more showery regime behind the front on
Thursday. There is some uncertainty in the track of the low as it
crosses into Bristol Bay Wednesday night. This will determine if
Southwest Alaska (especially Bristol bay) will see a period of
stronger easterly winds.

&&

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

Tonight and tomorrow will remain relatively calm across the Bering
and Aleutians. Northerly winds will then strengthen as the
Pacific low makes its way to Bristol Bay Tuesday night and
Wednesday. The strongest winds will be confined to the eastern
half of the Bering and Aleutians, with enhanced winds through bays
and passes.

&&

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

Bering/Aleutians

A weakening area of low pressure in the eastern Bering will bring
small craft winds to the area. A second and much stronger low will
move northwestward across the AKPEN and into the Bering Thursday
night into Friday morning. This low will bring widespread small
craft winds with small areas of gale force winds possible.
Confidence in the exact track of this system is low to moderate as
there are discrepancies on the placement of the low center between
models.

Gulf of Alaska

A strong area of low pressure will move across the western Gulf
Thursday afternoon through Friday evening. Widespread gale force
winds are likely, especially in the western Gulf. Confidence is
lower on the timing of these winds as there are discrepancies
between models on the placement of the low center. Another low
will move into the Gulf Saturday afternoon, though confidence
remains very low with regard to this low due to major
discrepancies in the placement and intensity of the low center.

&&

.LONG TERM FORECAST (Days 3 through 7/Thursday through Monday)...

The pattern will be highly amplified on Thursday with a deep
negatively-tilted upper level trough over the Bering/Aleutians and
a strong upper level ridge over the west coast of Canada. The
negative-tilt of this upper trough will be favorable for
cyclogenesis as a strong area of low pressure moves into the
western Gulf on Thursday and crosses the AKPEN into the Bering Sea
on Friday. Confidence is low in the exact placement of this low
due to discrepancies in guidance as this low crosses into the
Bering. Once in the Bering, this low will gradually weaken through
Sunday as the center of this low moves farther away from the core
of the jetstream and loses synoptic support. Another strong low
will move northeastward into the Gulf of Alaska on Saturday
afternoon then will gradually weaken while remaining in the
northern Gulf through Monday. Confidence with respect to this
system is very low as there are significant discrepancies with the
placement and intensity of this low.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Storm warning 120 130 131 132 136 137 138 139 150 155.
Gale warning 119 165 351 352.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...CB/MO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KM/SEB
MARINE/LONG TERM...ED