Small Craft Advisory 857, NWS Anchorage, AK

047 
FZAK51 PAFC 282355
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
355 PM AKDT Thu Oct 28 2021

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-291315-
355 PM AKDT Thu Oct 28 2021
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A 1002 mb low over Seward moves over Montague Island at 1007 mb Fri 
morning and dissipates Fri afternoon. A 970 mb low 265 nm South of 
Chignik moves over Chirikof Island at 975 mb for Sat afternoon. Its 
front extends from the Alaska Peninsula into the Western Gulf through
Sat afternoon.

$$

PKZ119-291315-
Cape Suckling to Cape Cleare-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 15 kt. Seas 7 ft.
.FRI...S wind 15 kt becoming SE 30 kt in the afternoon. Seas 6 ft
building to 9 ft in the afternoon.
.FRI NIGHT...SE wind 45 kt. Seas 15 ft. Rain.
.SAT...SE wind 40 kt. Seas 22 ft.
.SAT NIGHT...SE wind 45 kt. Seas 25 ft.
.SUN...E wind 40 kt. Seas 21 ft.
.MON THROUGH TUE...SE wind 25 kt. Seas 20 ft.

$$

PKZ120-291315-
Cape Cleare to Gore Point-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 15 kt. Seas 6 ft.
.FRI...SE wind 20 kt becoming E 40 kt in the afternoon. Seas 8 ft
building to 11 ft in the afternoon. Rain.
.FRI NIGHT...SE wind 40 kt. Seas 12 ft building to 20 ft after 
midnight. Rain.
.SAT...SE wind 45 kt. Seas 24 ft.
.SAT NIGHT...SE wind 40 kt. Seas 26 ft.
.SUN...E wind 30 kt. Seas 23 ft.
.MON...E wind 25 kt. Seas 16 ft.
.TUE...E wind 20 kt. Seas 16 ft.

$$

PKZ121-291315-
Resurrection Bay-
355 PM AKDT Thu Oct 28 2021

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft.
.FRI...Variable wind less than 10 kt becoming N 15 kt in the
afternoon. Seas 3 ft. Rain.
.FRI NIGHT...Variable wind 15 kt becoming S after midnight. Seas
3 ft. Rain.
.SAT AND SAT NIGHT...S wind 15 kt. Seas 3 ft.
.SUN...S wind 20 kt. Seas 4 ft.
.MON THROUGH TUE...N wind 10 kt. Seas 2 ft.

$$

PKZ125-291315-
Prince William Sound-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SE wind 15 kt. Seas 3 ft. Chance of thunderstorms. 
.FRI...SE wind 10 kt becoming E 20 kt in the afternoon. Seas 2 ft
building to 4 ft in the afternoon. Chance of thunderstorms in the
morning. 
.FRI NIGHT...E wind 40 kt. Seas 10 ft. Rain.
.SAT AND SAT NIGHT...SE wind 40 kt. Seas 10 ft.
.SUN...E wind 35 kt. Seas 9 ft.
.MON THROUGH TUE...E wind 20 kt. Seas 3 ft.

$$

PKZ126-291315-
Port Valdez-
355 PM AKDT Thu Oct 28 2021

.TONIGHT...E wind 10 kt in the evening becoming variable less than
10 kt. Seas 2 ft. Rain.
.FRI...Variable wind less than 10 kt. Seas 2 ft.
.FRI NIGHT...E wind 10 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...E wind 10 kt. Seas 2 ft.
.SUN THROUGH TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ127-291315-
Valdez Narrows-
355 PM AKDT Thu Oct 28 2021

.TONIGHT...N wind 15 kt diminishing to 10 kt after midnight. Seas
3 ft. Rain.
.FRI...N wind 20 kt. Seas 3 ft.
.FRI NIGHT...N wind 20 kt. Seas 3 ft. Rain.
.SAT...N wind 15 kt. Seas 3 ft.
.SAT NIGHT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-291315-
Valdez Arm-
355 PM AKDT Thu Oct 28 2021

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...NE wind 15 kt. Seas 3 ft. Widespread rain showers.
.FRI...NE wind 10 kt becoming NE wind 15 kt in the afternoon. Seas
3 ft. Rain showers.
.FRI NIGHT...E wind 30 kt. Seas 6 ft. Rain.
.SAT...E wind 30 kt. Seas 6 ft.
.SAT NIGHT...NE wind 25 kt. Seas 5 ft.
.SUN...NE wind 20 kt. Seas 3 ft.
.MON THROUGH TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ129-291315-
Passage Canal-
355 PM AKDT Thu Oct 28 2021

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...E wind 10 kt. Seas 2 ft. Rain.
.FRI...E wind 10 kt increasing to 15 kt in the afternoon. Seas 2 ft.
.FRI NIGHT...E wind 25 kt. Seas 4 ft. Rain.
.SAT...E wind 30 kt. Seas 5 ft.
.SAT NIGHT...E wind 25 kt. Seas 4 ft.
.SUN...E wind 20 kt. Seas 3 ft.
.MON THROUGH TUE...E wind 10 kt. Seas 2 ft.

$$

PKZ130-291315-
West of Barren Islands including Kamishak Bay-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 4 ft.
.FRI...E wind 20 kt increasing to 45 kt in the afternoon. Seas 5 ft 
building to 12 ft in the afternoon. Rain.
.FRI NIGHT...E wind 45 kt. Seas 13 ft. Rain.
.SAT...E wind 45 kt. Seas 13 ft.
.SAT NIGHT...E wind 30 kt. Seas 9 ft.
.SUN...E wind 30 kt. Seas 8 ft.
.MON...NE wind 25 kt. Seas 8 ft.
.TUE...NE wind 15 kt. Seas 5 ft.

$$

PKZ131-291315-
Barren Islands East-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 6 ft.
.FRI...SE wind 25 kt becoming E 45 kt in the afternoon. Seas 5 ft
building to 10 ft in the afternoon. Rain.
.FRI NIGHT...SE wind 45 kt. Seas 15 ft building to 21 ft after
midnight. Rain.
.SAT...SE wind 45 kt. Seas 25 ft.
.SAT NIGHT...SE wind 35 kt. Seas 25 ft.
.SUN...E wind 30 kt. Seas 23 ft.
.MON...E wind 25 kt. Seas 14 ft.
.TUE...E wind 20 kt. Seas 14 ft.

$$

PKZ132-291315-
Marmot Island to Sitkinak-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 15 kt becoming SE 20 kt after midnight. Seas
7 ft.
.FRI...SE wind 40 kt. Seas 9 ft building to 14 ft in the
afternoon. Rain.
.FRI NIGHT...SE wind 45 kt. Seas 24 ft. Rain.
.SAT...SE wind 45 kt. Seas 29 ft.
.SAT NIGHT...SE wind 35 kt. Seas 29 ft.
.SUN...E wind 25 kt. Seas 20 ft.
.MON...E wind 20 kt. Seas 13 ft.
.TUE...SE wind 15 kt. Seas 11 ft.

$$

PKZ136-291315-
Chiniak Bay-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft.
.FRI...E wind 25 kt increasing to 35 kt in the afternoon. Seas 6 ft 
building to 9 ft in the afternoon. Rain.
.FRI NIGHT...SE wind 40 kt. Seas 16 ft. Rain.
.SAT...SE wind 40 kt. Seas 16 ft.
.SAT NIGHT...SE wind 30 kt. Seas 12 ft.
.SUN...E wind 25 kt. Seas 8 ft.
.MON...E wind 15 kt. Seas 4 ft.
.TUE...SE wind 10 kt. Seas 3 ft.

$$

PKZ137-291315-
Marmot Bay-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...W wind 10 kt in the evening becoming variable less than
10 kt. Seas 3 ft.
.FRI...E wind 30 kt. Seas 6 ft building to 10 ft in the afternoon.
Rain.
.FRI NIGHT...SE wind 40 kt. Seas 16 ft. Rain.
.SAT...SE wind 40 kt. Seas 16 ft.
.SAT NIGHT...SE wind 30 kt. Seas 12 ft.
.SUN...E wind 25 kt. Seas 7 ft.
.MON...E wind 15 kt. Seas 4 ft.
.TUE...E wind 10 kt. Seas 3 ft.

$$

PKZ138-291315-
Shelikof Strait-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY...

.TONIGHT...SW wind 15 kt becoming variable 15 kt after midnight. 
Seas 4 ft.
.FRI...E wind 30 kt increasing to 45 kt in the afternoon. Seas
12 ft. Rain.
.FRI NIGHT...E wind 30 kt. Seas 9 ft. Rain.
.SAT...E wind 35 kt. Seas 9 ft.
.SAT NIGHT...E wind 25 kt. Seas 6 ft.
.SUN THROUGH MON...NE wind 20 kt. Seas 6 ft.
.TUE...NE wind 15 kt. Seas 5 ft.

$$

PKZ139-291315-
Cook Inlet Kalgin Island to Point Bede-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 10 kt. Seas 2 ft.
.FRI...E wind 15 kt becoming NE 35 kt in the afternoon. Seas 3 ft
building to 9 ft in the afternoon.
.FRI NIGHT...NE wind 40 kt. Seas 10 ft. Rain.
.SAT...E wind 35 kt. Seas 10 ft.
.SAT NIGHT...E wind 25 kt. Seas 6 ft.
.SUN...NE wind 25 kt. Seas 5 ft.
.MON...NE wind 20 kt. Seas 5 ft.
.TUE...NE wind 15 kt. Seas 4 ft.

$$

PKZ140-291315-
Cook Inlet North of Kalgin Island-
355 PM AKDT Thu Oct 28 2021

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...Variable wind less than 10 kt becoming S 10 kt after
midnight. Seas 2 ft.
.FRI...SE wind 10 kt becoming NE 20 kt in the afternoon. Seas 2 ft
building to 5 ft in the afternoon.
.FRI NIGHT...NE wind 30 kt. Seas 9 ft.
.SAT AND SAT NIGHT...E wind 30 kt. Seas 8 ft.
.SUN THROUGH MON...NE wind 20 kt. Seas 5 ft.
.TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ141-291315-
Kachemak Bay-
355 PM AKDT Thu Oct 28 2021

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 10 kt. Seas 2 ft.
.FRI...E wind 10 kt increasing to 25 kt in the afternoon. Seas 2 ft 
building to 5 ft in the afternoon. Rain.
.FRI NIGHT...SE wind 35 kt. Seas 5 ft. Rain.
.SAT...E wind 35 kt. Seas 5 ft.
.SAT NIGHT...E wind 25 kt. Seas 4 ft.
.SUN...E wind 20 kt. Seas 3 ft.
.MON...NE wind 15 kt. Seas 3 ft.
.TUE...E wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
Issued by National Weather Service Juneau AK
225 PM AKDT Wed Oct 27 2021

.ANALYSIS AND UPPER LEVELS...

A large upper low remains situated over the northern Bering with
a 90 to 100 knot upper-level jet helping to dig the low
southeastward toward the Alaska Peninsula. At the surface an
occluded front extends southeastward from the low center into
Nunavak Island and then curves southward into the Alaska Peninsula
as a cold front. Cold temperatures of -8 to -12 degrees Celsius
at 850mb are noted across the Bering and are slowly expanding
eastward toward the Kuskokwim Delta, which is resulting in light
snow over the Pribilofs. Ahead of the cold front is a weak warm
front lifting into the Lower Kuskokwim Valley with overcast
conditions and intermittent light rain overspreading the Kuskokwim
Delta and Bristol Bay. Temperatures over Bristol Bay and further
south across the Aleutians and Alaska Peninsula remain warm enough
for current precipitation to fall as rain, but will gradually
change over to snow as the cold front sweeps eastward. Over the
Gulf of Alaska, a mid-level trough is slowly approaching
Southeast Alaska with areas of stratus clouds and cirrus
stretching from Middleton Island into the Copper Basin. Much of
Southcentral remains dry with isolated snow showers in the
Matanuska-Susitna valleys.

&&

.MODEL DISCUSSION...
The models are handling synoptic features well over the Bering
and over the Gulf of Alaska. Good model agreement continues and
depicts a low over the Bering and a low over the Gulf of Alaska
gradually merging over interior Alaska through 24 hours. Beyond 24
hours models continue to show good agreement with a third low
undergoing significant amplification south of the Aleutians on
Friday and presenting an atmospheric river into the Kenai
Peninsula for a 12 to 24 hour period Friday night into Saturday.
Models diverge beyond 48 hours but do suggest southerly flow over
the Kenai Peninsula will become southeast and then easterly as an
amplified low and its trough axis pivot counterclockwise Saturday
morning. The evolution of this low over the next couple of days
will ultimately be the determiner of just how much rain areas like
Seward receive into the weekend.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3: Today
through Sunday Morning)...

...1230 PM UPDATE...

Little change made to the short term forecast today. Guidance
remains in good agreement regarding the high wind threat and
atmospheric river for the end of this week and into the weekend.

Minor changes made to the near term forecast to increase PoPs this
afternoon and evening for the Matanuska and Susitna Valleys.
Increase snow shower activity has been reported around Palmer so
far this morning with light accumulations occurring. 12z ANC RAOB
sounding shows a fairly dry layer below 6,000 ft; however a very
unstable layer with steep lapse rates exists above it aiding in
the enhanced shower activity around the area. Weak mid and upper
level shortwave energy and vorticity streaming northward into the
region have been able to squeeze out any moisture from the high
cloud deck despite the low level dry layer. Light, widely
scattered snow showers are expected to persist through the day
then diminish this evening. Expect lower visibility and minor
accumulations in areas that receive training showers.

...PREVIOUS DISCUSSION...

The weather pattern is about to turn much more active, culminating
in a major storm just in time for the Halloween weekend. The quiet
period is ongoing with very little going on weatherwise in the
short-term. A colder air mass is filtering into Southcentral,
which will make for one of our coldest days in quite a while with
high temperatures struggling to just a few degrees above freezing.
The saving grace as far as temperatures go is the abundant high
cloud cover, which will substantially limit how cold temperatures
get tonight, though widespread 20s are still expected due to
periods of clearer skies.

More clouds will move in ahead of an approaching weak shortwave,
which will bring a period of snow up Cook Inlet from southwest to
northeast through the day. Due to the small size of this feature,
the models are struggling with the timing and snowfall amounts,
but most areas should stay under an inch except for the higher
elevations where up to 2 inches of new snow are possible. There
will be more moisture available towards Prince William Sound, so
amounts from 3 to 5 inches are possible in the Kenai and Chugach
Mountains extending over to Whittier and Valdez. Snow showers will
persist over portions of the area for much of the day Thursday
into Thursday night, so localized areas could see higher totals.

For the first half of the day on Friday there will be quiet
weather for mainland Southcentral, but it will be the calm before
the storm. A very deep and highly amplified upper level trough
will dip all the way to near the Hawaiian Islands. Ahead of this
trough, deep southerly flow will transport that tropical moisture
northward into Southcentral in the form of an atmospheric river.
Now while the air mass will moderate significantly on its way
here, the air will be warm enough to raise snow levels to 5,000
feet by Saturday. Thus, any snow that may fall even in the higher
elevations at the onset of the precipitation Friday afternoon and
evening will quickly change over to rain, especially for the
coastal mountains.

The associated rain will hit Kodiak first beginning Friday
morning, then envelop all of the Kenai and Chugach mountains by
Friday evening. The atmospheric river (AR) will have its sights
set on Seward where rainfall totals of 5 to 8 inches are expected.
The potential for flooding from all this rain falling in a short
amount of time is significant, and future flood products will
likely be needed. Similar rainfall totals are possible in Kodiak
through Sunday as the AR realigns at Kodiak Island by Sunday.

Further north, the primary weather threat will be high winds. As
the leading front moves into the area, and the overall large-scale
winds turn more easterly with time, high winds gusting above
hurricane force are likely to develop, especially along Turnagain
Arm, Portage Valley, and the higher elevations of the Anchorage
Hillside. See the High Wind Watches that were issued for more
details. Other threats include the potential for significant
amounts of snow across the western Susitna Valley, some snowfall
and gusty winds across the Copper River Basin, and temperatures
warming well into the 40s by Saturday. Stay tuned for additional
products and updated forecasts.

&&

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

A weather front extends from St Matthew Island east to a 990 mb
low near Nunivak Island, and a 995 mb low near King Salmon, then
south this afternoon. Snow has been spreading inland long the
front along with gusty winds to 30 mph. There is still potential
for up to 3 inches of snow as the front moves inland, but most
area will see less than one inch. As the front move inland it will
weaken and drift south with a 996 mb low developing near Cook
Inlet. Weak low pressure will persist into Thursday with isolated
to scattered light snow showers. High pressure building into the
area Thursday from the northwest will bring some clearing and some
cooling temperatures. A strong low moving south of the AKPEN
Friday will wrap moisture north into the area with snow/rain mix
on the AKPEN becoming mostly snow as it moves into Bristol Bay
and the Lower Kuskokwim Valley Friday afternoon. This is
potentially the first significant storm of the season with
significant snowfall possible through the weekend. Detail are
still uncertain so watch for updates.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 to 3...Today
through Saturday afternoon)...

A 984 mb low will bring gale force winds to the Western Aleutians
this evening as it moves just south of Kiska. The low will move
east along 50N to just south of Atka by Thursday morning with the
gales spreading east. Strongest winds will be south of the
Aleutians. The low will continue east, and will be 250 nm south
of Cold Bay Friday morning at 978 mb. The low will spread a mix of
rain and snow showers to the Aleutian initially, but as the low
moves east strong north flow will develop over the Bering Sea with
snow showers developing in the Bering Sea and moving south over
the Aleutians.

&&

.MARINE (Days 3 through 5: Saturday through Monday)...
Bering/Aleutians
Strong gales and seas up to 15 ft over eastern Bering will
continue until Sat night. The next emerging low over the southern
Bering Sun afternoon could potentially elevate seas and winds to
gales near Pribilof Islands Sun night into early Mon morning.
Elsewhere, moderate seas and small crafts will continue
sporadically across the forecast area. For this reason, forecast
confidence is above average.

Gulf of Alaska
A nearly stationary complex North Pacific low and its associated
front are responsible for persistent gales and long period swells
of 20 to 25 ft across the Gulf through at least early Sun morning.
As seas and winds diminish Sun morning, the potential for gales to
return is favorable especially around the Barren Islands and east
of Kodiak Island in response to the next North Pacific low
trekking toward the Gulf Sun afternoon. The latter system will
again bring another strong episode of long period swells up to 22
ft on Monday especially over the central Gulf. For other parts of
the Gulf during most of the forecast period, small craft
conditions will continue into early next week. Overall, forecast
confidence remains above average.

&&

.Long Term Discussion (Days 4 through 7: Sunday through Wednesday)...

GFS and ECM differ quite a bit on the placement of the expected
lows transiting through the Bering and Gulf of Alaska. However,
solutions agreed to highlight strong winds and potentially heavy
rain across the Gulf and Prince William Sound, and over the
Aleutian Chain and Southwest Coast. Clearly, a firm ridge over the
State will maintain a quiet forecast for mostly inland portions of
Southcentral and Southwest. A frontal system over the eastern Gulf
will bring strong winds and rain across Prince William Sound and
eastern Kenai Peninsula starting Mon afternoon until late Mon
night. Meanwhile, strong winds and rain from a North Pacific low
will enter the central Aleutians beginning Mon afternoon. A
developing front associated with the latter system will then shift
through the eastern Bering into the Southwest Coast by early Tue
morning, leading to increased rain and stronger winds along the
gaps and passes. Both systems over the Bering and Gulf will bring
a lot of tropical moisture and warm temperatures days ahead.

&&

AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Watch: 101, 125.
 Special Weather Statement: 152, 161.
MARINE...Gales: 165, 170, 172, 174, 176-179, 185, 412, 414.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...BL
SOUTHCENTRAL ALASKA...JPW/CM
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SB
MARINE/LONG TERM...KO