Small Craft Advisory 831, NWS Anchorage, AK

079 
FZAK52 PAFC 021134
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
334 AM AKDT Thu Nov 2 2017

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.

PKZ199-030015-
334 AM AKDT Thu Nov 2 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A front in the western Aleutians will weaken through Sat morning. 
Fri morning...a 1024 mb low develops near 140 nm northwest of 
Adak and moves into the northern Bering through Sat morning.

$$

PKZ150-030015-
South of the AK Peninsula Sitkinak to Castle Cape-
334 AM AKDT Thu Nov 2 2017

.TODAY...Variable wind 10 kt. Seas 3 ft.
.TONIGHT...W wind 15 kt. Seas 3 ft.
.FRI...W wind 20 kt. Seas 4 ft.
.FRI NIGHT...W wind 15 kt. Seas 4 ft.
.SAT...SW wind 20 kt. Seas 6 ft.
.SUN THROUGH MON...N wind 25 kt. Seas 8 ft.

$$

PKZ155-030015-
South of the AK Peninsula Castle Cape to Cape Sarichef-
334 AM AKDT Thu Nov 2 2017

.TODAY...Variable wind 10 kt. Seas 5 ft.
.TONIGHT...S wind 15 kt. Seas 5 ft.
.FRI...S wind 15 kt. Seas 5 ft.
.FRI NIGHT...SE wind 20 kt. Seas 6 ft.
.SAT THROUGH MON...NE wind 20 kt. Seas 7 ft.

$$

PKZ160-030015-
Bristol Bay-
334 AM AKDT Thu Nov 2 2017

.TODAY...Variable wind less than 10 kt. Seas 2 ft. Areas of fog in
the morning.
.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Patchy fog.
.FRI...N wind 10 kt. Seas 2 ft. Patchy fog.
.FRI NIGHT...E wind 10 kt. Seas 2 ft.
.SAT...NW wind 20 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 20 kt. Seas 5 ft.

$$

PKZ165-030015-
Port Heiden to Cape Sarichef-
334 AM AKDT Thu Nov 2 2017

.TODAY...Variable wind 10 kt. Seas 5 ft. Areas of fog in the morning.
.TONIGHT...Variable wind 10 kt. Seas 5 ft. Patchy fog.
.FRI...SE wind 15 kt except variable 10 kt from Port Moller E.
Seas 4 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 3 ft.
.SAT THROUGH SUN...NE wind 20 kt. Seas 5 ft.
.MON...E wind 15 kt. Seas 5 ft.

$$

PKZ170-030015-
Cape Sarichef to Nikolski Bering Side-
334 AM AKDT Thu Nov 2 2017

.TODAY...SE wind 20 kt. Seas 6 ft.
.TONIGHT...SE wind 20 kt. Seas 6 ft.
.FRI...SE wind 20 kt. Seas 6 ft.
.FRI NIGHT...E wind 20 kt. Seas 4 ft.
.SAT THROUGH SUN...E wind 25 kt. Seas 7 ft.
.MON...SE wind 20 kt. Seas 7 ft.

$$

PKZ171-030015-
Unalaska Bay-
334 AM AKDT Thu Nov 2 2017

.TODAY...SE wind 15 kt. Seas 2 ft.
.TONIGHT...SE wind 15 kt. Seas 2 ft.
.FRI...SE wind 20 kt. Seas 2 ft.
.FRI NIGHT...SE wind 15 kt. Seas 2 ft.
.SAT...NE wind 15 kt. Seas 5 ft.
.SUN...E wind 15 kt. Seas 5 ft.
.MON...SE wind 10 kt. Seas 2 ft.

$$

PKZ172-030015-
Cape Sarichef to Nikolski Pacific Side-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...SE wind 20 kt. Seas 8 ft.
.TONIGHT...SE wind 20 kt. Seas 8 ft.
.FRI...SE wind 20 kt. Seas 8 ft.
.FRI NIGHT...E wind 20 kt. Seas 9 ft.
.SAT THROUGH SUN...E wind 25 kt. Seas 9 ft.
.MON...SE wind 20 kt. Seas 6 ft.

$$

PKZ173-030015-
Nikloski to Seguam Island Bering Side-
334 AM AKDT Thu Nov 2 2017

.TODAY...SE wind 20 kt. Seas 7 ft.
.TONIGHT...SE wind 20 kt. Seas 6 ft.
.FRI...SE wind 20 kt. Seas 6 ft.
.FRI NIGHT...NE wind 15 kt. Seas 7 ft.
.SAT...NE wind 25 kt. Seas 8 ft.
.SUN...E wind 25 kt. Seas 9 ft.
.MON...S wind 20 kt. Seas 8 ft.

$$

PKZ174-030015-
Nikolski to Seguam Island Pacific Side-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...SE wind 20 kt. Seas 10 ft.
.TONIGHT...SE wind 20 kt. Seas 9 ft.
.FRI...E wind 20 kt. Seas 9 ft.
.FRI NIGHT...NE wind 20 kt. Seas 10 ft.
.SAT...NE wind 25 kt. Seas 9 ft.
.SUN...E wind 25 kt. Seas 9 ft.
.MON...S wind 20 kt. Seas 7 ft.

$$

PKZ175-030015-
Seguam Island to Adak Bering Side-
334 AM AKDT Thu Nov 2 2017

.TODAY...E wind 15 kt. Seas 6 ft.
.TONIGHT...SE wind 20 kt. Seas 6 ft.
.FRI...SE wind 15 kt. Seas 6 ft.
.FRI NIGHT...N wind 20 kt. Seas 6 ft.
.SAT...NE wind 25 kt. Seas 8 ft.
.SUN...SE wind 25 kt. Seas 9 ft.
.MON...SW wind 20 kt. Seas 8 ft.

$$

PKZ176-030015-
Seguam Island to Adak Pacific Side-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...E wind 20 kt. Seas 10 ft.
.TONIGHT...SE wind 20 kt. Seas 9 ft.
.FRI...E wind 15 kt. Seas 9 ft.
.FRI NIGHT...NE wind 20 kt. Seas 9 ft.
.SAT...NE wind 25 kt. Seas 10 ft.
.SUN...SE wind 25 kt. Seas 9 ft.
.MON...SW wind 20 kt. Seas 9 ft.

$$

PKZ177-030015-
Adak to Kiska-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY TODAY AND FRIDAY...

.TODAY...N wind 20 kt. Seas 9 ft.
.TONIGHT...NE wind 15 kt. Seas 7 ft.
.FRI...N wind 20 kt. Seas 8 ft.
.FRI NIGHT...N wind 20 kt. Seas 9 ft.
.SAT...E wind 25 kt. Seas 9 ft.
.SUN...SE wind 25 kt. Seas 9 ft.
.MON...SW wind 25 kt. Seas 13 ft.

$$

PKZ178-030015-
Kiska to Attu-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...SE wind 30 kt except 15 kt E of Shemya. Seas 9 ft.
.TONIGHT...S wind 30 kt becoming SW 20 kt after midnight. Seas
11 ft.
.FRI...W wind 20 kt. Seas 11 ft.
.FRI NIGHT...E wind 15 kt. Seas 9 ft.
.SAT...SE wind 40 kt. Seas 18 ft.
.SUN...S wind 40 kt. Seas 18 ft.
.MON...SW wind 30 kt. Seas 17 ft.

$$

PKZ179-030015-
Pribilof Islands Near Shore Waters-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...SE wind increasing to 20 kt. Seas 8 ft. Rain.
.TONIGHT...S wind 15 kt. Seas 7 ft.
.FRI...S wind 15 kt. Seas 6 ft.
.FRI NIGHT...S wind 15 kt. Seas 5 ft.
.SAT...N wind 15 kt. Seas 5 ft.
.SUN...E wind 25 kt. Seas 7 ft.
.MON...SE wind 25 kt. Seas 8 ft.

$$

PKZ180-030015-
Kuskokwim Delta and Etolin Strait-
334 AM AKDT Thu Nov 2 2017

.TODAY...S wind 10 kt increasing to 15 kt in the afternoon. Seas
4 ft.
.TONIGHT...S wind 10 kt. Seas 4 ft. Patchy fog.
.FRI...SE wind 15 kt. Seas 4 ft.
.FRI NIGHT...S wind 15 kt. Seas 3 ft.
.SAT...NW wind 20 kt. Seas 5 ft.
.SUN...NE wind 20 kt. Seas 5 ft.
.MON...E wind 20 kt. Seas 6 ft.

$$

PKZ181-030015-
North and West of Nunivak Island-
334 AM AKDT Thu Nov 2 2017

.TODAY...S wind 15 kt. Seas 5 ft. Rain.
.TONIGHT...E wind 15 kt. Seas 5 ft. Areas of fog.
.FRI...SE wind 20 kt. Seas 5 ft.
.FRI NIGHT...S wind 20 kt. Seas 5 ft.
.SAT...W wind 25 kt. Seas 8 ft.
.SUN...NE wind 20 kt. Seas 7 ft.
.MON...SE wind 25 kt. Seas 8 ft.

$$

PKZ185-030015-
Saint Matthew Island Waters-
334 AM AKDT Thu Nov 2 2017

...SMALL CRAFT ADVISORY TODAY AND FRIDAY...

.TODAY...SW wind 15 kt. Seas 9 ft.
.TONIGHT...Variable wind 10 kt becoming E 20 kt after midnight.
Seas 7 ft.
.FRI...S wind 25 kt. Seas 7 ft. Rain.
.FRI NIGHT...SW wind 25 kt. Seas 8 ft.
.SAT...W wind 25 kt. Seas 9 ft.
.SUN THROUGH MON...S wind 30 kt. Seas 18 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
454 AM AKDT Wed Nov 1 2017

.ANALYSIS AND UPPER LEVELS...
Water vapor satellite looks much less messy today as ridging
builds over the state. High pressure aloft is the main synoptic
feature, centered over the western coast of Alaska. The
responsible longwave trough is centered just east of the
Kamchatka Peninsula, with a weak front stretched across the
western/central Bering Sea.

A weak outflow pattern is setup across the southern mainland with
light offshore flow in most places, except for favored gaps along
the north Gulf coast. As far as active weather is concerned, fog
and stratus is about it, with a bank of low clouds/fog along the
Chugach from the Matanuska Valley through the Kenai Peninsula as
well as along the north side of the Alaska Peninsula.

&&

.MODEL DISCUSSION...
Guidance still struggling on how to handle the low-level
moisture(fog/stratus) in place over the Cook Inlet region.
Persistence/observations and conceptual models will play a much
larger role in the forecast today/tonight as opposed to numerical
guidance.

&&

.AVIATION...
PANC...The low stratus did not get mixed out with the dry air
aloft today, making it able to build again early this morning. The
uncertainty in the TAF still revolves around this feature. Likely
there will be some improvement in ceilings/visibility through the
day today but the deck will not completely dissipate, and
lower/thicken overnight tonight.

&&

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

Upper ridging is building in over Southcentral this morning.
Northerly flow and weak cold air advection over the Copper Basin
is still supporting a marginal outflow gap wind event along the
coast. However, the pressure gradient is much weaker farther west
near Cook Inlet, and as a result, fog and stratus continues to be
an issue from the Kenai Peninsula north through Anchorage and the
Matanuska Valley. Polar orbiting nighttime radiance satellite
imagery depicts the low stratus and fog well, with fog also
stretching into valleys and fjords (including Turnagain Arm). With
warming temperatures aloft and continued strong low level
inversions, it seems unlikely that the fog and stratus improve
much today, so the dense fog advisories will be continued through
Thursday morning. Thursday evening and Thursday night, a shortwave
trough will clip the northern part of Southcentral, bringing in
increasing low level offshore winds which should help improve the
fog situation.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Dry weather with low coastal stratus and valley fog forming
overnight but burning off by each afternoon will continue through
Thursday as an upper level high remains centered south of the
Alaska Peninsula. By Thursday evening, a weak frontal system in
the Bering will push over the Kuskokwim Delta bringing clouds and
some light precipitation with it. As the stronger portion of the
supporting upper level shortwave trough continues east into
interior Alaska the front will stretch east over the lower
Kuskokwim Valley Thursday night before dissipating Friday morning
as the ridge axis re-amplifies over Southwest Alaska.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The frontal system stretching across the central Bering will
continue to weaken through the day today. Another frontal wave
will lift north across the central Aleutians this afternoon and
then continue northeast across the central and eastern Bering
tonight through Thursday. A front associated with a Kamchatka low
will swing into the western Aleutians Friday afternoon and
evening. High pressure will build across the Bering Friday night
through Saturday.

&&

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

Northwesterly offshore flow will increase Thursday night over
Southcentral Alaska. As colder air pushes into the Interior and a
trough deepens along the northern Gulf Coast, expect gusty gap
winds to peak Friday morning/afternoon and subside Friday night.
Zonal flow Saturday will quickly amplify as a sharp ridge builds
over the Bering Sea by Saturday night. Downstream of the ridge,
shortwave energy will dig southeastward from northwest Alaska
south to the northern Gulf Coast. A surface cold front co-located
with the upper-wave will push south Saturday night, bringing in a
rush of much colder air to Southcentral. This will kick off a
drying and cooling trend that will last through early next week as
deep northerly flow prevails. A chance for some precipitation over
Southcentral exists with the frontal passage Saturday night,
however moisture will be limited amid the northerly flow, and for
now the setup looks fairly weak.

Further west, a weakening front stretching from the western
Aleutians through the Kuskokwim Coast Thursday will continue to
bring rain showers to the area. A weak surface low will develop
along the front over the central Bering Thursday night and track
northeastward to the Bering Strait by Friday afternoon. This will
bring more precipitation to the northern Kuskokwim Coast Friday
before the region dries out by Saturday. A front over the North
Pacific will push north to the Aleutian Islands Friday evening,
setting up a rainy weekend for the Islands and southern Alaska
Peninsula. The front will fall apart by Sunday evening as a much
stronger front associated with a Kamchatka low approaches from the
west.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Dense Fog Advisory 101 111.
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...MTL
SOUTHCENTRAL ALASKA...JA
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JR
LONG TERM...RD