Small Craft Advisory 478, NWS Anchorage, AK

961 
FZAK52 PAFC 202354
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
354 PM AKDT Tue Jun 20 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.

PKZ199-211315-
354 PM AKDT Tue Jun 20 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

Bogoslof Volcano 53 NM West of Dutch Harbor remains active.

A 1001 mb low 700 nm southwest of Shemya Tue afternoon moves 290
nm southwest of Shemya at 993 mb Wed afternoon. This system moves
160 nm south of Shemya at 999 mb Thu afternoon moves 80 nm south
of Shemya at 1002 mb Fri morning. An associated front enters the 
Western Aleutians Wed morning before elongating from the western 
Bering into the Central Aleutians through Fri morning.

$$

PKZ150-211315-
South of the AK Peninsula Sitkinak to Castle Cape-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...NW wind 20 kt. Seas 5 ft.
.WED...NW wind 15 kt. Seas 4 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 4 ft.
.THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...Variable wind 10 kt. Seas 5 ft.
.SAT THROUGH SUN...W wind 15 kt. Seas 6 ft.

$$

PKZ155-211315-
South of the AK Peninsula Castle Cape to Cape Sarichef-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 5 ft.
.WED...W wind 15 kt. Seas 4 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...Variable wind 10 kt. Seas 5 ft.
.SAT...SW wind 15 kt. Seas 6 ft.
.SUN...SW wind 20 kt. Seas 10 ft.

$$

PKZ160-211315-
Bristol Bay-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 20 kt. Seas 4 ft. Patchy fog.
.WED...W wind 15 kt. Seas 3 ft. Patchy fog.
.WED NIGHT...W wind 15 kt diminishing to 10 kt after midnight.
Seas 3 ft. Patchy fog.
.THU AND THU NIGHT...SW wind 10 kt. Seas 2 ft.
.FRI...W wind 10 kt. Seas 3 ft.
.SAT...W wind 15 kt. Seas 3 ft.
.SUN...W wind 10 kt. Seas 3 ft.

$$

PKZ165-211315-
Port Heiden to Cape Sarichef-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 3 ft. Patchy fog.
.WED...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft. Patchy fog.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 2 ft.
.FRI...Variable wind 10 kt. Seas 3 ft.
.SAT THROUGH SUN...S wind 20 kt. Seas 4 ft.

$$

PKZ170-211315-
Cape Sarichef to Nikolski Bering Side-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 3 ft. Patchy fog.
.WED...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft. Patchy fog.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 2 ft.
.FRI...S wind 20 kt. Seas 5 ft.
.SAT THROUGH SUN...S wind 25 kt. Seas 8 ft.

$$

PKZ171-211315-
Unalaska Bay-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...NW wind 15 kt becoming W after midnight. Seas 2 ft.
.WED...NW wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU AND THU NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.FRI...S wind 10 kt. Seas 2 ft.
.SAT...S wind 15 kt. Seas 2 ft.
.SUN...S wind 20 kt. Seas 2 ft.

$$

PKZ172-211315-
Cape Sarichef to Nikolski Pacific Side-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 5 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 4 ft.
.FRI...SW wind 20 kt. Seas 7 ft.
.SAT THROUGH SUN...S wind 25 kt. Seas 14 ft.

$$

PKZ173-211315-
Nikloski to Seguam Island Bering Side-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.WED...Variable wind 10 kt. Seas 3 ft.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft.
.THU...SE wind 15 kt. Seas 3 ft.
.THU NIGHT...SE wind 20 kt. Seas 5 ft.
.FRI...S wind 25 kt. Seas 7 ft.
.SAT THROUGH SUN...S wind 25 kt. Seas 11 ft.

$$

PKZ174-211315-
Nikolski to Seguam Island Pacific Side-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...Variable wind 10 kt. Seas 5 ft. Patchy fog.
.WED...Variable wind 10 kt. Seas 5 ft.
.WED NIGHT...Variable wind 10 kt. Seas 4 ft.
.THU...S wind 15 kt. Seas 4 ft.
.THU NIGHT...S wind 20 kt. Seas 8 ft.
.FRI...S wind 25 kt. Seas 9 ft.
.SAT THROUGH SUN...S wind 30 kt. Seas 14 ft.

$$

PKZ175-211315-
Seguam Island to Adak Bering Side-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.WED...S wind 15 kt. Seas 3 ft.
.WED NIGHT...SE wind 20 kt. Seas 4 ft.
.THU AND THU NIGHT...SE wind 30 kt. Seas 8 ft.
.FRI...SE wind 30 kt. Seas 8 ft.
.SAT...SE wind 25 kt. Seas 8 ft.
.SUN...SW wind 25 kt. Seas 8 ft.

$$

PKZ176-211315-
Seguam Island to Adak Pacific Side-
354 PM AKDT Tue Jun 20 2017

...SMALL CRAFT ADVISORY WEDNESDAY NIGHT...

.TONIGHT...Variable wind 10 kt. Seas 5 ft. Patchy fog.
.WED...S wind 15 kt. Seas 4 ft.
.WED NIGHT...SE wind 25 kt. Seas 7 ft.
.THU...SE wind 30 kt. Seas 13 ft.
.THU NIGHT...SE wind 35 kt. Seas 14 ft.
.FRI THROUGH SAT...S wind 30 kt. Seas 13 ft.
.SUN...SW wind 30 kt. Seas 12 ft.

$$

PKZ177-211315-
Adak to Kiska-
354 PM AKDT Tue Jun 20 2017

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...S wind increasing to 20 kt. Seas 5 ft.
.WED...SE wind 30 kt. Seas 10 ft.
.WED NIGHT...SE wind 35 kt. Seas 14 ft.
.THU AND THU NIGHT...SE wind 35 kt. Seas 16 ft.
.FRI...S wind 25 kt. Seas 11 ft.
.SAT...E wind 25 kt. Seas 9 ft.
.SUN...NW wind 20 kt. Seas 7 ft.

$$

PKZ178-211315-
Kiska to Attu-
354 PM AKDT Tue Jun 20 2017

...GALE WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...S wind increasing to 25 kt. Seas 6 ft.
.WED...SE wind 35 kt. Seas 9 ft building to 14 ft in the
afternoon. Rain.
.WED NIGHT...SE wind 35 kt. Seas 18 ft. Rain.
.THU...SE wind 35 kt. Seas 17 ft.
.THU NIGHT...SE wind 25 kt. Seas 11 ft.
.FRI...S wind 20 kt. Seas 10 ft.
.SAT...NW wind 15 kt. Seas 7 ft.
.SUN...Variable wind 10 kt. Seas 6 ft.

$$

PKZ179-211315-
Pribilof Islands Near Shore Waters-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...Variable wind 10 kt. Seas 3 ft. Areas of fog.
.WED...Variable wind 10 kt. Seas 3 ft. Areas of fog.
.WED NIGHT...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...S wind 20 kt. Seas 6 ft.
.SAT THROUGH SUN...S wind 25 kt. Seas 11 ft.

$$

PKZ180-211315-
Kuskokwim Delta and Etolin Strait-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 3 ft. Patchy fog.
.WED...NW wind 10 kt increasing to 15 kt in the afternoon. Seas
3 ft. Patchy fog.
.WED NIGHT...NW wind 15 kt. Seas 3 ft. Patchy fog.
.THU AND THU NIGHT...NW wind 15 kt. Seas 3 ft.
.FRI...W wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...S wind 15 kt. Seas 5 ft.

$$

PKZ181-211315-
North and West of Nunivak Island-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...W wind 15 kt. Seas 4 ft. Patchy fog.
.WED...Variable wind 10 kt. Seas 3 ft. Patchy fog.
.WED NIGHT...SW wind 15 kt. Seas 4 ft. Patchy fog.
.THU...SW wind 15 kt. Seas 4 ft.
.THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...S wind 15 kt. Seas 4 ft.
.SAT THROUGH SUN...S wind 20 kt. Seas 7 ft.

$$

PKZ185-211315-
Saint Matthew Island Waters-
354 PM AKDT Tue Jun 20 2017

.TONIGHT...SW wind 20 kt. Seas 6 ft. Patchy fog.
.WED...S wind 20 kt. Seas 6 ft. Patchy fog.
.WED NIGHT...S wind 20 kt. Seas 6 ft. Patchy fog.
.THU AND THU NIGHT...S wind 15 kt. Seas 6 ft.
.FRI THROUGH SUN...SE wind 20 kt. Seas 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion...CORRECTED
National Weather Service Anchorage AK
732 PM AKDT Mon Jun 19 2017

.ANALYSIS AND UPPER LEVELS...
Low pressure in the Gulf of Alaska will continue to slowly move
towards SE Alaska. To the northeast of this low is a front that
will move to east to west bringing active weather across the
region. High pressure exists across northern Alaska as well as the
across the Bering, bringing the typical summer stratus across the
sea.

&&

.MODEL DISCUSSION...
Synoptically speaking, most model guidance is in great agreement
through the short term (hour 60 or so). In the short term all
models agree with the timing and intensity of the shortwave that
will be driving the surface front and showers/thunderstorms this
afternoon. There is good agreement with wetting rains
overspreading much of southcentral but some disagreement to
strength and longevity. Differences begin to unfold late tomorrow
with the evolution of the surface low across the Gulf. By 12z
Weds there is a small spread with a weak low developing to the
south of the current and parent low. The Fujiwara interaction is
taking the developing low across the SE panhandle and most
guidance is weakening the parent low, while the Canadian is the
biggest outlier this afternoon as it only slowly weakens the
parent low SE of Kodiak.

&&

.AVIATION...
PANC...VFR conditions and light southerly winds will persist
until the early evening when southerly winds will pick up. VFR
conditions are still anticipated to continue as rain overspreads
the region towards the early morning hours, with winds peaking in
the 20-25kt gust range.

&&

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

The next 24 hours will be very active across Southcentral.

This afternoon and this evening, an easterly wave moving across
the area will provide the lift for showers and thunderstorms
across portions of the area. The greatest threat for storms will
be across the northern Susitna Valley. Already this afternoon,
storms have been forming along the Talkeetnas, and any significant
breaks in the cloud cover will be enough to allow for convective
development. Any storms will move westward with time across the
Susitna Valley.

Tonight into Tuesday, the aforementioned easterly wave will team
up with a surface front and associated low pressure in the Gulf to
produce widespread wetting rains over nearly all of Southcentral.
Rain shower activity has already begun across Prince William
Sound and will continue to spread westward, though the bulk of
the precipitation isn't expected in Anchorage until Tuesday
morning. The total rainfall expected over the lower elevations
through Tuesday afternoon will be in the one-third to one-half
inch range, though anywhere that gets persistent showers and
storms, such as in the mountains, could see much more. The morning
rain and afternoon cloud cover means most areas will be much
cooler on Tuesday, with highs unlikely to get out of the mid to
upper 50s.

On Wednesday, while the precipitation threat will have diminished
except along the mountains, mostly cloudy skies will prevent the
sun from achieving its full potential, so highs are only expected
to recover into the lower 60s. Gradual north to south clearing
means the Susitna Valley and Copper River Basin will be where the
highest temps in the mid to upper 60s will be found.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2...Mon and Tue)...

Diurnal heating along a thermal trough axis extending from the
interior to the Kuskokwim Valley and northern Bristol will bring
scattered showers during peak heating late today. A few
thunderstorms are expected along the Alaska and Aleutian Ranges
where a weak easterly wave is expected to move across, enhancing
convective activity this evening. Thunderstorm activity is
expected to end by midnight with the loss of sunlight. Isolated
showers across the Kuskokwim Delta this evening will be short
lived as a shortwave from the Bering Strait is blocked by an upper
ridge building south from the eastern Brooks Range in addition to
a surface ridge edging inland from the Bering.

By Tuesday, the Bering ridge shifts inland across the southwest
bringing dry conditions to much of the region through Thursday.
The exception to this are The Alaska and Aleutian Ranges which will
see activity continue through mid week as a front stalls across these
mountains. Isolated thunderstorms for this area will be diurnally
influenced and confined on Wednesday to the Alaska Range.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2...Mon and
Tue)...

An expansive ridge across the Bering will hold influence across
much of the Bering through mid week. A weak front moves pushes
across the western Aleutians early Tuesday with a slow northward
push. This front quickly diminishes by Tuesday afternoon as it
races ahead of the upper low center. The next front moves into the
western Aleutians Wednesday night with a slow steady push north
and east through Thursday. This better organized system is
expected to produce gale force winds along the boundary as it
moves through, accompanied by light to moderate rain.

&&

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

The upper level ridge from south of the Aleutians into southwest
Alaska across the interior will split into two ridges as an upper
level low over the Gulf of Alaska Pushes north Friday and the
large upper level Arctic trough sweeps across the state from the
Brooks Range north. The upper level ridging remains over the
eastern Aleutians and eastern Bering Sea through Saturday then
builds back into southwest Alaska and the interior Sunday as the
upper level low over the Gulf moves off to the southeast. A strong
upper level low will track into the western and central Bering Sea
through the weekend behind the aforementioned ridge. This upper
low will track to the north toward the Bering Strait as the upper
ridge extends from the Gulf of Alaska into the central and eastern
interior by late Monday and Tuesday.

This will usher in a return of the thermal trough and warmer
temperatures over much of the southern mainland by this weekend
with increased afternoon and evening convection through the
weekend. Over the Bering Sea and Aleutians the weather will
transition from marine stratus and fog typically seen under the
surface high to a wetter and windier regime one would expect with
the surface based low moving across the Bering and the associated
front that sweeps along the Aleutians through the weekend.

Model agreement has remained consistent through the long term and
the national guidance remained heavily weighted toward the
operational model guidance through the weekend.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...NONE.
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...SS
SOUTHCENTRAL ALASKA...JW
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...KH
LONG TERM...SA