Gale Warning 449, NWS Anchorage, AK

073 
FZAK52 PAFC 010023
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
423 PM AKDT Mon Aug 31 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.

PKZ199-011345-
423 PM AKDT Mon Aug 31 2020
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A front over the eastern Bering weakens by Tue morning. 

$$

PKZ150-011345-
South of the AK Peninsula Sitkinak to Castle Cape-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 14 ft.
.TUE...W wind 25 kt diminishing to 15 kt in the afternoon. Seas 12 
ft.
.TUE NIGHT...W wind 15 kt. Seas 8 ft.
.WED AND WED NIGHT...W wind 15 kt. Seas 6 ft.
.THU...W wind 15 kt. Seas 5 ft.
.FRI...SE wind 30 kt. Seas 4 ft.
.SAT...SE wind 25 kt. Seas 4 ft.

$$

PKZ155-011345-
South of the AK Peninsula Castle Cape to Cape Sarichef-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...W wind 25 kt. Seas 13 ft.
.TUE...W wind 20 kt. Seas 10 ft.
.TUE NIGHT...W wind 15 kt. Seas 7 ft.
.WED...W wind 15 kt. Seas 6 ft.
.WED NIGHT...W wind 20 kt. Seas 5 ft.
.THU...W wind 15 kt. Seas 5 ft.
.FRI...E wind 30 kt. Seas 5 ft.
.SAT...SE wind 20 kt. Seas 5 ft.

$$

PKZ160-011345-
Bristol Bay-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TUESDAY...

.TONIGHT...W wind 20 kt. Seas 7 ft.
.TUE...W wind 25 kt. Seas 7 ft.
.TUE NIGHT...W wind 20 kt. Seas 5 ft.
.WED...NW wind 10 kt. Seas 3 ft.
.WED NIGHT...NW wind 15 kt. Seas 3 ft.
.THU...W wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...E wind 25 kt. Seas 4 ft.

$$

PKZ165-011345-
Port Heiden to Cape Sarichef-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...W wind 25 kt. Seas 8 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.TUE NIGHT...W wind 15 kt. Seas 6 ft.
.WED AND WED NIGHT...NW wind 15 kt. Seas 4 ft.
.THU...W wind 15 kt. Seas 4 ft.
.FRI...E wind 25 kt. Seas 4 ft.
.SAT...NE wind 25 kt. Seas 4 ft.

$$

PKZ170-011345-
Cape Sarichef to Nikolski Bering Side-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...W wind 25 kt diminishing to 15 kt after midnight. Seas 9 
ft.
.TUE...W wind 15 kt. Seas 8 ft.
.TUE NIGHT...W wind 15 kt. Seas 6 ft.
.WED AND WED NIGHT...NW wind 20 kt. Seas 5 ft.
.THU...S wind 15 kt. Seas 4 ft.
.FRI...E wind 20 kt. Seas 4 ft.
.SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ171-011345-
Unalaska Bay-
423 PM AKDT Mon Aug 31 2020

.TONIGHT...W wind 20 kt. Seas 4 ft.
.TUE...W wind 15 kt. Seas 2 ft.
.TUE NIGHT...W wind 10 kt. Seas 2 ft.
.WED AND WED NIGHT...W wind 15 kt. Seas 4 ft.
.THU...S wind 10 kt. Seas 2 ft.
.FRI...E wind 15 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 3 ft.

$$

PKZ172-011345-
Cape Sarichef to Nikolski Pacific Side-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...W wind 20 kt. Seas 11 ft.
.TUE...W wind 15 kt. Seas 8 ft.
.TUE NIGHT...W wind 20 kt. Seas 6 ft.
.WED AND WED NIGHT...NW wind 20 kt. Seas 6 ft.
.THU...SW wind 15 kt. Seas 4 ft.
.FRI...E wind 20 kt. Seas 5 ft.
.SAT...NE wind 20 kt. Seas 5 ft.

$$

PKZ173-011345-
Nikolski to Seguam Island Bering Side-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY...

.TONIGHT...W wind 15 kt. Seas 9 ft.
.TUE...W wind 20 kt. Seas 8 ft.
.TUE NIGHT...W wind 20 kt. Seas 7 ft.
.WED AND WED NIGHT...W wind 15 kt. Seas 6 ft.
.THU...S wind 15 kt. Seas 4 ft.
.FRI...E wind 15 kt. Seas 4 ft.
.SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ174-011345-
Nikolski to Seguam Island Pacific Side-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY THROUGH TUESDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 9 ft.
.TUE...W wind 15 kt. Seas 8 ft.
.TUE NIGHT...W wind 15 kt in the morning increasing to 25 kt. Seas 7
ft.
.WED AND WED NIGHT...NW wind 20 kt. Seas 7 ft.
.THU...S wind 15 kt. Seas 5 ft.
.FRI...E wind 20 kt. Seas 5 ft.
.SAT...NE wind 20 kt. Seas 5 ft.

$$

PKZ175-011345-
Seguam Island to Adak Bering Side-
423 PM AKDT Mon Aug 31 2020

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

.TONIGHT...W wind 15 kt. Seas 8 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.TUE NIGHT...W wind 25 kt. Seas 7 ft.
.WED...NW wind 20 kt. Seas 6 ft.
.WED NIGHT...SW wind 15 kt. Seas 5 ft.
.THU...S wind 20 kt. Seas 4 ft.
.FRI...E wind 15 kt. Seas 4 ft.
.SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ176-011345-
Seguam Island to Adak Pacific Side-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TUESDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 6 ft.
.TUE NIGHT...W wind 25 kt. Seas 7 ft.
.WED...NW wind 20 kt. Seas 7 ft.
.WED NIGHT...W wind 15 kt. Seas 4 ft.
.THU...S wind 20 kt. Seas 6 ft.
.FRI...E wind 20 kt. Seas 6 ft.
.SAT...NE wind 20 kt. Seas 4 ft.

$$

PKZ177-011345-
Adak to Kiska-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TUESDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.TUE NIGHT...W wind 25 kt diminishing to 15 kt after midnight. Seas 
8 ft.
.WED AND WED NIGHT...SW wind 15 kt. Seas 5 ft.
.THU...S wind 25 kt. Seas 8 ft.
.FRI...NE wind 20 kt. Seas 5 ft.
.SAT...N wind 20 kt. Seas 5 ft.

$$

PKZ178-011345-
Kiska to Attu-
423 PM AKDT Mon Aug 31 2020

.TONIGHT...W wind 15 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.TUE NIGHT...W wind 15 kt. Seas 6 ft.
.WED...SW wind 20 kt. Seas 5 ft.
.WED NIGHT...SW wind 25 kt. Seas 7 ft.
.THU THROUGH SAT...NW wind 25 kt. Seas 8 ft.

$$

PKZ179-011345-
Pribilof Islands Near Shore Waters-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...W wind 20 kt. Seas 8 ft.
.TUE...W wind 15 kt. Seas 6 ft.
.TUE NIGHT...NW wind 15 kt. Seas 5 ft.
.WED...NW wind 15 kt. Seas 4 ft.
.WED NIGHT...W wind 15 kt. Seas 4 ft.
.THU...S wind 15 kt. Seas 4 ft.
.FRI...SE wind 15 kt. Seas 4 ft.
.SAT...NE wind 15 kt. Seas 3 ft.

$$

PKZ180-011345-
Kuskokwim Delta and Etolin Strait-
423 PM AKDT Mon Aug 31 2020

.TONIGHT...NW wind 20 kt. Seas 6 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.TUE NIGHT...NW wind 10 kt. Seas 4 ft.
.WED...N wind 10 kt. Seas 3 ft.
.WED NIGHT...NW wind 15 kt. Seas 3 ft.
.THU...SW wind 15 kt. Seas 3 ft.
.FRI...SE wind 25 kt. Seas 4 ft.
.SAT...NE wind 25 kt. Seas 3 ft.

$$

PKZ181-011345-
North and West of Nunivak Island-
423 PM AKDT Mon Aug 31 2020

.TONIGHT...NW wind 20 kt. Seas 7 ft.
.TUE...NW wind 20 kt. Seas 6 ft.
.TUE NIGHT...NW wind 15 kt. Seas 5 ft.
.WED AND WED NIGHT...NW wind 15 kt. Seas 3 ft.
.THU...S wind 15 kt. Seas 3 ft.
.FRI...SE wind 15 kt. Seas 3 ft.
.SAT...NE wind 20 kt. Seas 3 ft.

$$

PKZ185-011345-
Saint Matthew Island Waters-
423 PM AKDT Mon Aug 31 2020

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 15 kt. Seas 8 ft.
.TUE...NW wind 15 kt. Seas 6 ft.
.TUE NIGHT...NW wind 15 kt except SW wind 10 kt W of Saint Matthew
Island. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft.
.THU...E wind 15 kt. Seas 4 ft.
.FRI...E wind 20 kt. Seas 5 ft.
.SAT...NE wind 15 kt. Seas 3 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
558 PM AKDT Sun Aug 30 2020

.ANALYSIS AND UPPER LEVELS...
A powerful storm center, former Typhoon Bavi, was moving eastward
toward Bristol Bay with the leading edge of the spreading rain
across Southwest Alaska and into the western Gulf. Strong winds on
the southern periphery of the storm were showing gusts in excess
of 70 mph across the eastern Aleutians and portions of the Alaska
Peninsula. A wind report of 120 mph was reported at Dutch Harbor
as the storm center was passing. Winds in advance of the storm
along the Bristol Bay coast were increasing. The cloud shield in
advance of the front was rapidly advancing over Southcentral with
some rain spreading to Cook Inlet. Gap winds we also increasing
across Southcentral (Turnagain Arm, Knik River Valley, and along
the Copper River to name a few).

&&

.MODEL DISCUSSION...
Models in in good synoptic scale agreement through the short
term. Thought the precipitation patterns are generally the same,
models do differ of QPF amounts over the next 24-36 hrs. The will
lean toward the higher Resolution models in that respect.

&&

.AVIATION...
PANC...VFR. Strong gusty southerly winds will develop across the
airport complex by early evening and continue through the late
night hours before diminishing.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:Monday
through Wednesday)...

Weather across Southcentral will continue to be influenced by a
strong low pressure system over Southwest AK Monday morning. As
this system continues to move onshore and northeast, flow over
Southcentral will transition to the south/southwest. The primary
impact of this shift will be a more favorable moisture fetch for
the Susitna Valley to get persistent, and at times moderate to
heavy rain. As such, the Talkeetna Mountains could receive
between 3.5 and 4.5 inches of rain by Tuesday morning. Southerly
flow over the northern Gulf coast could also produce 2.5 to 3.5
inches of rain in areas like Cordova and Valdez as well as inland
over the Wrangell Mountains. Chances for rain should lessen by
Tuesday afternoon but southerly flow and transient weak upper
level vorticies will provide chances for rain, mostly over the
terrain, through Wednesday.

The other impact of the southerly fetch will bring strong winds
up the Cook Inlet early monday morning, which will keep winds
gusty over west Anchorage throughout the day Monday. Additionally,
strong winds are expected to push through Copper River Valley
during the day Monday. By Tuesday winds are expected to be calm
throughout the AOR as the primary low continues to weaken and move
over northern Alaska.

&&

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

A 960 mb low pressure system is presently coming ashore over Cape
Newenham. This low pressure will continue to bring the area
strong winds and periods of rain through Monday morning. High
wind warnings remain in effect for Southwest Alaska with the
strongest winds in Bristol Bay, along the coast mainly east of
Dillingham and from King Salmon and areas southward. Expect the
strongest winds to occur from now through this evening. Much of
Bristol Bay will see Storm Force winds continuing from now
through early Monday especially in eastern portions, however
Hurricane force gusts are possible across eastern Bristol Bay.
Winds will gradually ease as we head into Monday morning as the
low pressure moves inland and weakens.

This storm also continue to bring a good amount of rain as it has
copious moisture from tropical regions with 1 to 1.5" of rain
possible across the Bristol Bay region and near King Salmon and
areas northward. Less rain is expected in the YK delta region with
up to a half inch in most areas. Rain will decrease Monday and
Tuesday as the system moves towards the Interior of Alaska. The
steadiest rainfall will occur through the remainder of today into
Monday morning before becoming more showery in nature.

Coastal flooding remains expected in Bristol Bay due to strong
southwesterly onshore flow creating the potential for water levels
to rise 2 to 4 feet above highest astronomical tide this evening
through Monday morning. Areas with a concave coastline (where the
coastline curves into the land) are the most prone to coastal
flooding and erosion as the onshore flow will help funnel the
water in these areas. Areas with a convex coastline (i.e. Cape
Newenham where the land points outward) are less prone to coastal
flooding as the water is less likely to funnel with the onshore
flow in these regions. A Coastal Flood Advisory remains in effect
from 8 PM AKDT this evening through 9 AM AKDT Monday for Cape
Constantine to Port Heiden.

&&

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

A 960 mb low pressure system will continue to move onshore over
Cape Newenham and then inland while weakening. Storm force winds
are expected across Bristol Bay and along the Bering side of the
AKPEN with Hurricane force gusts possible the remainder of the
afternoon and into the overnight hours. Locally higher winds and
gusts are expected in the gaps due to the localized funneling of
winds. A High Wind Warning remains in effect for the western
Alaska Peninsula through 8pm AKDT this evening. Winds will
gradually ease from west to east across the Aleutians this evening
through Monday afternoon.

High seas from 18-25ft are expected south of the central
Aleutians (Pacific side) due to the high end gale force southwesterly
winds combined with ample fetch for these seas to build. Seas
will be locally higher while wave periods will be locally shorter
at times as the west-southwesterly winds and west- southwesterly
primary swell direction will oppose the east- northeasterly
currents and locally stack the seas. Seas will gradually abate
and lengthen in period from west to east across the
Bering/Aleutians Sunday evening through Monday evening.

Ample rainfall is expected from this storm in the Aleutians. The
highest rainfall amounts are expected in the mountains due to
upsloping. Rainfall amounts will total between 0.75" and 1.00" in
those areas through Monday afternoon.

&&

.MARINE (Days 3 through 5/Wednesday through Friday)...

For the forecast period, a fairly benign pattern is expected
across the Gulf and the Bering. Thursday afternoon, there is a
chance for a weak low to move into the northwestern Bering which
would bring an increase in winds to the area. Despite uncertainty
with the track, winds and waves should not reach above small craft
advisory at this time. Around the same time, another weak low is
forecasted to move across the Aleutians, beginning with the
western Chain. At this time, it looks as if that low will dip
south into the Northern Pacific late Friday and should remain
below small craft criteria. Late Friday, models are in alignment
that a front associated with a low in the northern Pacific will
propagate north and enter the western Gulf. Chances for stronger
waves and winds are currently being tracked with this system.

&&

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

Model guidance for the long term forecast period continues to
suggest upper level troughing across much of the state of Alaska.
As a result, a cool, wet, and cloudy pattern remains expected for
the foreseeable future as we move further into Fall. Towards the
very end of the forecast period on Saturday, almost all model
guidance is showing an upper level ridge over the North Pacific.
The placement and intensity of this ridge will be crucial as an
upper level trough is expected to move southward through the
Bering and into the North Pacific as this ridge builds northward.
In between, the potential exists for an atmospheric river type
pattern to develop. Model guidance shows multiple systems moving
northward and then tracking across the Gulf of Alaska on the
northern periphery of this ridge. Therefore, the long term
forecast period is currently keying on above normal rainfall.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Flood Watch 111-145. Coastal Flood Advisory 161. High
Wind Warning 161 181.
MARINE...Gale 119 120 125 130 131 132 138
139 140 351 352 150 155 172 180 414. Storm 160 165.

&&

SYNOPSIS AND MODEL DISCUSSION...BC
SOUTHCENTRAL ALASKA...CJ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MV
MARINE/LONG TERM...CK