Small Craft Advisory 681, NWS Anchorage, AK

907 
FZAK51 PAFC 142354
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
354 PM AKDT Thu Sep 14 2017

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.

PKZ197-151300-
354 PM AKDT Thu Sep 14 2017
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A front over the western Gulf dissipates this evening. Another 
front moves into the southwestern Gulf Fri evening then develops
into a 990 mb low near Chiniak late Fri night...then the low 
moves into Southwest Alaska by midday Sat.

$$

PKZ119-151300-
Cape Suckling to Cape Cleare-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...SE wind 15 kt increasing to 25 kt by late evening. Seas 
7 ft building to 10 ft by late evening. Rain showers.
.FRI...S wind 20 kt. Along the coast...SE wind 25 kt becoming E 15 
kt in the afternoon. Seas 9 ft subsiding to 6 ft in the afternoon. 
Rain showers.
.FRI NIGHT...SE wind 15 kt increasing to 25 kt by midnight. Seas
6 ft building to 8 ft by midnight. Rain.
.SAT...SE wind 35 kt. Seas 7 ft.
.SAT NIGHT...SE wind 25 kt. Seas 8 ft.
.SUN...NW wind 20 kt. Seas 9 ft.
.MON THROUGH TUE...S wind 15 kt. Seas 7 ft.

$$

PKZ120-151300-
Cape Cleare to Gore Point-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY NIGHT...

.TONIGHT...SE wind 25 kt becoming S 15 kt after midnight. Seas
11 ft subsiding to 8 ft after midnight.
.FRI...S wind 15 kt. Seas 7 ft.
.FRI NIGHT...SE wind 15 kt increasing to 25 kt after midnight. Seas 
7 ft. Rain.
.SAT...SE wind 30 kt. Seas 7 ft.
.SAT NIGHT...E wind 15 kt. Seas 8 ft.
.SUN...NW wind 15 kt. Seas 9 ft.
.MON THROUGH TUE...S wind 15 kt. Seas 6 ft.

$$

PKZ121-151300-
Resurrection Bay-
354 PM AKDT Thu Sep 14 2017

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

$$

PKZ125-151300-
Prince William Sound-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY NIGHT...

.TONIGHT...E wind 25 kt. Seas 4 ft building to 6 ft after
midnight. Rain showers.
.FRI...SE wind 20 kt. Seas 4 ft. Rain.
.FRI NIGHT...SE wind 25 kt. Seas 4 ft. Rain.
.SAT...E wind 30 kt. Seas 6 ft.
.SAT NIGHT...E wind 25 kt. Seas 4 ft.
.SUN...NW wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...SE wind 10 kt. Seas 2 ft.

$$

PKZ126-151300-
Port Valdez-
354 PM AKDT Thu Sep 14 2017

.TONIGHT...Variable wind less than 10 kt. Seas 2 ft. Patchy fog.
Rain showers.
.FRI...Variable wind less than 10 kt. Seas 2 ft. Patchy fog. Rain
showers.
.FRI NIGHT...Variable wind less than 10 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...NE wind 10 kt. Seas 2 ft.
.SUN THROUGH TUE...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ127-151300-
Valdez Narrows-
354 PM AKDT Thu Sep 14 2017

.TONIGHT...NE wind 10 kt. Seas 2 ft. Rain showers.
.FRI...NE wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft. Rain showers.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...NE wind 20 kt. Seas 3 ft.
.SUN THROUGH MON...Variable wind less than 10 kt. Seas 2 ft.
.TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ128-151300-
Valdez Arm-
354 PM AKDT Thu Sep 14 2017

.TONIGHT...NE wind 10 kt increasing to 15 kt after midnight. Seas
2 ft. Rain showers.
.FRI...NE wind 10 kt. Seas 2 ft. Rain showers.
.FRI NIGHT...NE wind 10 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...NE wind 15 kt. Seas 3 ft.
.SUN...Variable wind less than 10 kt. Seas 2 ft.
.MON THROUGH TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-151300-
Passage Canal-
354 PM AKDT Thu Sep 14 2017

.TONIGHT...E wind 20 kt. Seas 3 ft. Rain.
.FRI...E wind 15 kt. Seas 2 ft. Rain.
.FRI NIGHT...E wind 15 kt. Seas 2 ft. Rain.
.SAT AND SAT NIGHT...E wind 25 kt. Seas 4 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...E wind 20 kt. Seas 3 ft.

$$

PKZ130-151300-
West of Barren Islands including Kamishak Bay-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...S wind 15 kt. Gusts to 30 kt in the evening. Seas 4 ft.
.FRI...S wind 15 kt becoming SE 25 kt in the afternoon. Seas 4 ft
building to 8 ft in the afternoon.
.FRI NIGHT...SE wind 30 kt. Seas 8 ft. Rain showers.
.SAT...E wind 30 kt. Seas 7 ft.
.SAT NIGHT...NE wind 15 kt. Seas 4 ft.
.SUN...W wind 20 kt. Seas 5 ft.
.MON...Variable wind 10 kt. Seas 3 ft.
.TUE...Variable wind 10 kt. Seas 2 ft.

$$

PKZ131-151300-
Barren Islands East-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY NIGHT...

.TONIGHT...S wind 25 kt becoming SW 15 kt by late evening. Seas
12 ft subsiding to 8 ft by late evening.
.FRI...SE wind 20 kt. Seas 7 ft.
.FRI NIGHT...SE wind 30 kt. Seas 8 ft.
.SAT...S wind 30 kt. Seas 8 ft.
.SAT NIGHT...E wind 15 kt. Seas 10 ft.
.SUN...NW wind 20 kt. Seas 9 ft.
.MON THROUGH TUE...SW wind 15 kt. Seas 6 ft.

$$

PKZ132-151300-
Marmot Island to Sitkinak-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 8 ft.
.FRI...S wind 15 kt increasing to 25 kt in the afternoon. Seas
7 ft.
.FRI NIGHT...SE wind 25 kt. From Dangerous Cape S...SE wind 25 kt 
becoming W 30 kt after midnight. Seas 9 ft.
.SAT...SW wind 25 kt. Seas 13 ft.
.SAT NIGHT...NW wind 30 kt. Seas 17 ft.
.SUN...NW wind 20 kt. Seas 15 ft.
.MON...SW wind 15 kt. Seas 7 ft.
.TUE...SW wind 20 kt. Seas 8 ft.

$$

PKZ136-151300-
Chiniak Bay-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...S wind 15 kt diminishing to 10 kt after midnight. Seas
3 ft subsiding to 1 ft after midnight.
.FRI...S wind 10 kt increasing to 15 kt in the afternoon. Seas
building to 3 ft.
.FRI NIGHT...SE wind 25 kt becoming E 15 kt after midnight. Seas
8 ft diminishing to 5 ft after midnight. Rain.
.SAT...SW wind 15 kt. Seas 2 ft.
.SAT NIGHT...E wind 10 kt. Seas 3 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...SW wind 10 kt. Seas 2 ft.

$$

PKZ137-151300-
Marmot Bay-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...Variable wind less than 10 kt. Seas 3 ft.
.FRI...SE wind 10 kt increasing to 20 kt in the afternoon. Seas
3 ft building to 7 ft in the afternoon.
.FRI NIGHT...SE wind 25 kt. Seas 9 ft. Rain.
.SAT...S wind 15 kt. Seas 3 ft.
.SAT NIGHT...NE wind 10 kt. Seas 3 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...SW wind 10 kt. Seas 3 ft.

$$

PKZ138-151300-
Shelikof Strait-
354 PM AKDT Thu Sep 14 2017

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 15 kt. Seas 3 ft.
.FRI...SE wind 15 kt increasing to 25 kt in the afternoon. Seas
3 ft building to 8 ft in the afternoon.
.FRI NIGHT...SE wind 25 kt becoming Variable 15 kt after midnight. 
Seas 9 ft subsiding to 5 ft after midnight. Rain.
.SAT...S wind 20 kt. Seas 5 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 3 ft.
.SUN...W wind 15 kt. Seas 3 ft.
.MON...Variable wind 10 kt. Seas 3 ft.
.TUE...SW wind 15 kt. Seas 3 ft.

$$

PKZ139-151300-
Cook Inlet Kalgin Island to Point Bede-
354 PM AKDT Thu Sep 14 2017

.TONIGHT...NE wind 15 kt becoming SE after midnight. Seas 4 ft.
.FRI...SE wind 20 kt...except N 10 kt N of Anchor Point. Seas 4 ft.
.FRI NIGHT...SE wind 20 kt...except NE 15 kt N of Anchor Point.
Seas 5 ft. Rain.
.SAT...NE wind 20 kt. Seas 5 ft.
.SAT NIGHT...N wind 10 kt. Seas 3 ft.
.SUN...W wind 10 kt. Seas 3 ft.
.MON...E wind 10 kt. Seas 2 ft.
.TUE...SE wind 10 kt. Seas 2 ft.

$$

PKZ140-151300-
Cook Inlet North of Kalgin Island-
354 PM AKDT Thu Sep 14 2017

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

$$

PKZ141-151300-
Kachemak Bay-
354 PM AKDT Thu Sep 14 2017

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

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
428 PM AKDT Wed Sep 13 2017

.ANALYSIS AND UPPER LEVELS...

The longwave pattern has changed very little the past 24 hours as
an anchoring upper low remains over Eastern Siberia with
shortwave troughs at the base of the longwave moving through
Southwest Alaska. A more prominent shortwave trough is now moving
inland across Bristol Bay and the Lower Kuskokwim Valley. This low
helped tighten up the warm front which enhanced rainfall rates
overnight with some locations in Bristol Bay recording over 1.5"
of rainfall. Farther east across the Alaska Range, rainfall was
much lighter and was relegated to upslope portions along the
North Gulf Coast as well as in the Northern Susitna Valley. A
strong cross-barrier pressure gradient helped support gusty
southeast winds across Anchorage, the Matanuska Valley, and the
Copper Basin, and these winds continue to remain gusty this
afternoon.

Another shortwave trough is moving at the base of the longwave
trough along and south of Dutch harbor. This weak shortwave will
eventually lift north into the Gulf of Alaska and Southcentral
tonight into Thursday.

&&

.MODEL DISCUSSION...
The numerical weather models are in excellent agreement with the
overall large scale synoptic features, but rapidly fall apart with
the development of a strong storm force low expected over the
Bering Sea Thursday evening through Saturday morning. The GFS and
NAM models have been extremely erratic and difficult to use since
every run is dramatically different with track and the location of
the swath of strongest winds. The ECMWF has been rock solid in
the track and strength, so that model, along with the Canadian
GDPS was favored as these models combined help maintain a
continuity forecast. Across Southcentral, high resolution models
were favored for their superior handling of downslope drying and
strong gap winds.

&&

.AVIATION...
PANC...VFR conditions will persist. With a tight pressure gradient
in place, gusty winds expected to continue through Thursday
afternoon before diminishing late afternoon and early evening.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Gusty gap winds and a significant amount of downsloping on leeward
side of the mountains has been the weather story across
Southcentral Alaska today. The jet stream wavered far enough to
the west to keep the precipitation relegated to along the coast
and the western side of Cook Inlet. As of Tuesday afternoon the
jet is now moving eastward and bringing enhanced rainfall with it
which will continue eastward overnight.

In spite of the Anchorage area seeing good south to southwest
flow aloft, the strong boundary layer winds will continue to keep
much rainfall out of the areas. There may be a few periods of
light rainfall overnight, but at this time it looks like just some
sprinkles. The gusty winds across town will continue into tomorrow
and then begin to diminish by Thursday evening.

Farther north in the Matanuska Valley, there should be slightly
more rain as the topography is better to bring into that area
with this pattern.

The Copper River Basin will see rain in the mountains but lower
levels will see gusty winds from the south which will keep
precipitation at bay with the downsloping there as well.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Steady rain will continue for the Bristol Bay area, and to a
lesser extent, the Kuskokwim Valley through Thursday as the
longwave trough remains over the Mainland. Whereas, over the
Kuskokwim delta rain will remain more scattered in nature.
Thursday evening the pattern begins to change as a very fall-like
system takes shape in the Bering Sea. The strong low pressure
system will bring a front to the southwest coast by Friday
morning, bringing increased winds out of the southeast and
another round of rain to the area.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A couple of weak lingering troughs will keep showers and areas of
rain across the Bering through late tonight, but the real story
is a developing fall system for Thursday. A rapidly developing
low will bring gale-force winds on the front side of the system
to the central Aleutians and Bering Sea Thursday, then spread
northeastward into the eastern Bering and Alaska Peninsula by
overnight Thursday into Friday morning. As the system reaches
peak intensity sometime later on Friday, winds on the backside of
the system will ramp up with potentially hurricane-force gusts.

Models continue to struggle with the exact positioning of this
system and timing of the peak winds. This creates some uncertainty
in when and where the strongest winds will set up, between Friday
evening and Saturday morning, over the Eastern Bering or
potentially over the Eastern Aleutians and Alaska Peninsula. There
is slightly higher potential for the highest swath of winds to
track by the Pribilof Islands Friday afternoon/evening. Stay tuned
to the forecast.

&&

.LONG TERM FORECAST (Days 3 through 7)...
A highly amplified pattern is expected across Alaska through most
of next week as a strong subtropical jet south of the state
interacts with Arctic shortwave energy to the north. To start, a
strong surface low over the Bering looks to weaken and cross into
the Gulf over the weekend, though there is still a fair amount of
model disagreement regarding this feature. The EC/Canadian models
continue to keep the system more south in the Bering and then
move the center directly into the Gulf. The GFS/NAM keep the low
center a bit further north then split the system after Saturday,
with the main center quasi-stationary near Nunivak Island and a
secondary low forming in the Gulf. This difference looks to
propagate through the midterm forecast as the EC/Canadian eject
the Gulf low out to the east and build an upper level ridge in
behind it, while the GFS keeps an upper level low centered over
the west/central part of the state, which in turn suppresses the
ridge trying to build in over the North Pacific. Due to the
inconsistent GFS runs over the past couple of days the
EC/Canadian model was the preferred solution for the long term
forecast. Looking past midweek, all models are hinting at a
shortwave trough dipping down from the Arctic into the central
Bering which, depending on how it interacts with Northern Pacific
energy, could form another strong Bering low.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gale 155 165 170-177 179 412-414.

&&

SYNOPSIS AND MODEL DISCUSSION...JA
SOUTHCENTRAL ALASKA...EZ
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...TP
LONG TERM...KVP