Small Craft Advisory 730, NWS Anchorage, AK

137 
FZAK51 PAFC 291151
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
351 AM AKDT Fri Sep 29 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.

PKZ197-300045-
351 AM AKDT Fri Sep 29 2017
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

A broad 1003 mb low 55 nm northeast of Kodiak City will move to 
230 nm southeast of Kodiak City and will weaken to 1022 mb by Sat
afternoon. High pressure will build over the Gulf through Sun 
morning.

$$

PKZ119-300045-
Cape Suckling to Cape Cleare-
351 AM AKDT Fri Sep 29 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...SE wind 15 kt in the morning becoming variable 10 kt.
Seas 8 ft.
.TONIGHT...Variable wind 10 kt. Seas 4 ft.
.SAT...NW wind 15 kt. Seas 3 ft.
.SAT NIGHT...NW wind 15 kt. Seas 4 ft.
.SUN...E wind 30 kt. Seas 7 ft.
.MON...SE wind 30 kt. Seas 14 ft.
.TUE...SE wind 25 kt. Seas 12 ft.

$$

PKZ120-300045-
Cape Cleare to Gore Point-
351 AM AKDT Fri Sep 29 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...SE wind 20 kt. Seas 8 ft.
.TONIGHT...Variable wind 10 kt. Seas 5 ft.
.SAT...Variable wind 10 kt. Seas 4 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 3 ft.
.SUN THROUGH MON...E wind 35 kt. Seas 15 ft.
.TUE...SE wind 15 kt. Seas 11 ft.

$$

PKZ121-300045-
Resurrection Bay-
351 AM AKDT Fri Sep 29 2017

.TODAY...Variable wind less than 10 kt. Seas 2 ft. Widespread rain
showers.
.TONIGHT...N wind 10 kt increasing to 15 kt after midnight. Seas
3 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SAT NIGHT...N wind 15 kt. Seas 3 ft.
.SUN...N wind 10 kt. Seas 2 ft.
.MON...N wind 15 kt. Seas 3 ft.
.TUE...N wind 10 kt. Seas 2 ft.

$$

PKZ125-300045-
Prince William Sound-
351 AM AKDT Fri Sep 29 2017

.TODAY...E wind 20 kt in the morning becoming variable less than 10 
kt. Seas 3 ft.
.TONIGHT...NW wind 10 kt increasing to 15 kt after midnight. Seas
3 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SAT NIGHT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 20 kt. Seas 4 ft.
.TUE...E wind 15 kt. Seas 3 ft.

$$

PKZ126-300045-
Port Valdez-
351 AM AKDT Fri Sep 29 2017

.TODAY...Variable wind less than 10 kt. Seas 2 ft.
.TONIGHT...Variable wind less than 10 kt becoming NE 10 kt after
midnight. Seas 2 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SUN THROUGH TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ127-300045-
Valdez Narrows-
351 AM AKDT Fri Sep 29 2017

.TODAY...NE wind 10 kt. Seas 2 ft.
.TONIGHT...NE wind 20 kt. Seas 3 ft.
.SAT...NE wind 20 kt. Seas 3 ft.
.SAT NIGHT...NE wind 15 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 20 kt. Seas 3 ft.
.TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-300045-
Valdez Arm-
351 AM AKDT Fri Sep 29 2017

.TODAY...NE wind 15 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.TONIGHT...NE wind 15 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 3 ft.
.SAT NIGHT...NE wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...NE wind 15 kt. Seas 3 ft.
.TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-300045-
Passage Canal-
351 AM AKDT Fri Sep 29 2017

.TODAY...E wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft. Widespread rain showers.
.TONIGHT...W wind 10 kt increasing to 15 kt after midnight. Seas
2 ft.
.SAT...W wind 15 kt. Seas 2 ft.
.SAT NIGHT...W wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 20 kt. Seas 3 ft.
.TUE...E wind 10 kt. Seas 2 ft.

$$

PKZ130-300045-
West of Barren Islands including Kamishak Bay-
351 AM AKDT Fri Sep 29 2017

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...NW wind increasing to 25 kt. Seas building to 6 ft.
.TONIGHT...NW wind 25 kt. Seas 6 ft.
.SAT...NW wind 20 kt. Seas 5 ft.
.SAT NIGHT...NW wind 20 kt. Seas 5 ft.
.SUN...E wind 40 kt. Seas 16 ft.
.MON...E wind 40 kt. Seas 13 ft.
.TUE...SE wind 15 kt. Seas 4 ft.

$$

PKZ131-300045-
Barren Islands East-
351 AM AKDT Fri Sep 29 2017

...SMALL CRAFT ADVISORY SATURDAY...

.TODAY...NE wind 20 kt. Seas 6 ft.
.TONIGHT...NE wind 20 kt. Seas 5 ft.
.SAT...NW wind 25 kt. Seas 5 ft.
.SAT NIGHT...NW wind 20 kt. Seas 4 ft.
.SUN THROUGH MON...SE wind 35 kt. Seas 17 ft.
.TUE...Variable wind 10 kt. Seas 9 ft.

$$

PKZ132-300045-
Marmot Island to Sitkinak-
351 AM AKDT Fri Sep 29 2017

.TODAY...NW wind 20 kt. Seas 5 ft.
.TONIGHT...N wind 20 kt. Seas 5 ft.
.SAT...NW wind 20 kt. Seas 4 ft.
.SAT NIGHT...N wind 15 kt. Seas 3 ft.
.SUN...E wind 35 kt. Seas 17 ft.
.MON...S wind 25 kt. Seas 14 ft.
.TUE...SW wind 20 kt. Seas 8 ft.

$$

PKZ136-300045-
Chiniak Bay-
351 AM AKDT Fri Sep 29 2017

.TODAY...NW wind 15 kt. Seas 2 ft.
.TONIGHT...NW wind 20 kt. Seas 3 ft.
.SAT...NW wind 15 kt diminishing to 10 kt in the afternoon. Seas
2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 3 ft.
.SUN...E wind 25 kt. Seas 8 ft.
.MON...SE wind 20 kt. Seas 7 ft.
.TUE...SW wind 10 kt. Seas 2 ft.

$$

PKZ137-300045-
Marmot Bay-
351 AM AKDT Fri Sep 29 2017

.TODAY...NW wind 15 kt. Seas 3 ft.
.TONIGHT...N wind 15 kt. Seas 3 ft.
.SAT...NW wind 15 kt becoming W 10 kt in the afternoon. Seas 2 ft.
.SAT NIGHT...NW wind 10 kt. Seas 3 ft.
.SUN...E wind 25 kt. Seas 10 ft.
.MON...SE wind 20 kt. Seas 7 ft.
.TUE...S wind 10 kt. Seas 3 ft.

$$

PKZ138-300045-
Shelikof Strait-
351 AM AKDT Fri Sep 29 2017

.TODAY...NW wind 20 kt...strongest out of bays and passes. Seas 4 
ft.
.TONIGHT...N wind 20 kt. Seas 4 ft.
.SAT...W wind 15 kt. Seas 3 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN...NE wind 30 kt. Seas 12 ft.
.MON...E wind 25 kt. Seas 7 ft.
.TUE...SW wind 15 kt. Seas 4 ft.

$$

PKZ139-300045-
Cook Inlet Kalgin Island to Point Bede-
351 AM AKDT Fri Sep 29 2017

.TODAY...N wind increasing to 20 kt. Seas 5 ft.
.TONIGHT...N wind 20 kt. Seas 5 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SAT NIGHT...N wind 15 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 25 kt. Seas 7 ft.
.TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ140-300045-
Cook Inlet North of Kalgin Island-
351 AM AKDT Fri Sep 29 2017

.TODAY...NE wind increasing to 20 kt. Seas 4 ft.
.TONIGHT...N wind 15 kt. Seas 3 ft.
.SAT...Variable wind less than 10 kt. Seas 1 ft.
.SAT NIGHT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...NE wind 20 kt. Seas 4 ft.
.TUE...NE wind 10 kt. Seas 2 ft.

$$

PKZ141-300045-
Kachemak Bay-
351 AM AKDT Fri Sep 29 2017

.TODAY...Variable wind less than 10 kt becoming N 10 kt in the 
afternoon. Seas 2 ft. Rain showers.
.TONIGHT...N wind 15 kt becoming NE 10 kt after midnight. Seas 2
ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SAT NIGHT...N wind 10 kt. Seas 2 ft.
.SUN THROUGH MON...E wind 25 kt. Seas 5 ft.
.TUE...E wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
437 PM AKDT Thu Sep 28 2017

.ANALYSIS AND UPPER LEVELS...
An upper level trough extends out the Arctic, through the interior
of the state and southward through the western Gulf of Alaska.
The upper level ridge has greatly amplified from yesterday over
the western Bering Sea. These features will both move to the east
over the next few days bringing in a change to the weather pattern
over the mainland part of the state.
At the surface there remain a low in the western Gulf of Alaska
with ridge over the western Bering Sea which is keeping the
northerly gradient over most of the Bering and Southwest mainland.
A ridge is also along the north Gulf coast which is increasing
winds through Turnagain Arm, the Knik Valley as well as along the
Copper River.

&&

.MODEL DISCUSSION...
Models remain in good agreement through the weekend with the only
item that may cause some impact to the forecast being the low
currently in the western Gulf of Alaska. This low is elongated
with two centers...one just southeast of Kodiak Island and the
other near the southern tip of the Kenai Peninsula. Models
underestimated the strength of the northern most low yesterday
and are still presenting slightly different solutions to it today.
The most likely scenario will be for the southern low the become
the dominant one as the northern one weakens and then drifts
southeastward before dissipating Saturday. Models are still
struggling a lot early next week with two lows moving into the
Aleutians and Alaska Peninsula regions. While the longwave pattern
is similar, the surface low center positions are hundreds of
miles different between the GFS and ECMWF models.

&&

.AVIATION...
PANC...VFR winds will persist through Friday. There is the chance
of the Turnagain Arm wind moving over the airport from late in the
afternoon through mid evening tonight. At this time it looks to
remain mostly just south of the airport so the TAF reflects this,
however there could be some gustier conditions that occur for a
few hours during the aforementioned time frame.

&&

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

A slowly weakening vertically stacked low located over the Gulf
about halfway between Seward and Kodiak will remain the primary
driver for the weather across Southcentral for the next 24 hours
or so. As a result, a general precipitation pattern of rain
showers along the Alaska Range and Prince William Sound with
relatively little in between will continue into Friday morning.
The stout easterly flow across Prince William Sound will keep
potentially heavy rain going across the western portion of the
Sound through tonight. With regards to the winds, the main gap
winds are through Turnagain Arm and through the Copper River
Basin. Both will diminish overnight as the pressure gradient
slackens.

During the day Friday, a front pushing southeastward out of the
interior will cause off-and-on shower activity across much of
Southcentral through the day, though most areas should keep total
rainfall totals from the frontal passage under a tenth of an inch
or two.

On Friday night, the aforementioned front will clear the Cook
Inlet region early in the evening and dissipate over western
Prince William Sound and the Copper River Basin by midnight.
Robust clearing behind the front will commence area-wide, making
for near optimal stargazing and aurora watching conditions!
Anchorage International should get its first night in the 30s,
with those values challenged again Saturday night. Rapidly
building high pressure over interior Alaska along with some colder
air will invigorate many of the gap winds across Southcentral
Friday night into Saturday from Seward, eastern Turnagain Arm,
Whittier, Valdez, and the Copper River Delta as strong offshore
flow develops. The winds should help to keep those affected
communities warmer Friday night.

A weak upper level disturbance clips the Copper River Basin
during the day Saturday making for mostly cloudy conditions there.
Elsewhere, other than for some high cloudiness, the rest of
Southcentral gets to enjoy a day with nearly full sunshine and
highs in the lower 50s. We'll repeat that again for Sunday too!

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Rain will linger around the Aleutian and Alaska Ranges tonight
into tomorrow morning before ridging builds in from the west.
High pressure will then dominate southwest Alaska into the
weekend.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
High pressure over the Western Aleutians and Bering will slowly
track east into the eastern Bering by Saturday. Behind the
ridging, a front will push over the Western Aleutians Friday night
bringing rain and gale force winds to the area. On Saturday it
will continue its easterly track towards the Central Aleutians and
Bering.

&&

.LONG TERM FORECAST (Days 3 through 7)...

The forecast period commences with a high amplitude ridge spanning
from the Gulf Of Alaska to the North Slope and a closed low south
of Sand Point. Upstream, there will be another vortex churning
just east of Kamchatka. Sensible weather-wise, expect another
sunny day on Sunday over the Anchorage Metro area and the Prince
William Sound. As time elapses, anticipate a progressive pattern
as the pair of lows careen eastward. By midweek, another cyclone
moves into the Bering. Overall, past Sunday the models continue
to struggle with this transition period which impact the timing
and the placement of the precipitation shields. High confidence
that next week will be dominated by unsettled and moist
conditions.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 178 411.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...JW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...DK
LONG TERM...PS