Small Craft Advisory 483, NWS Anchorage, AK

919 
FZAK52 PAFC 172327
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
327 PM AKDT Thu Jun 17 2021

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.

PKZ199-181200-
327 PM AKDT Thu Jun 17 2021

.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA PENINSULA 
WATERS AND THE ALEUTIAN ISLANDS...

A 985 mb low 650 nm southwest of Dutch Harbor will move 620 nm
south of Dutch Harbor at 996 mb Friday afternoon. The low then 
moves 510 nm southeast of Dutch Harbor Saturday afternoon. A 985 
mb North Pacific low will move 170 nm southwest of Shemya by Saturday
afternoon.

$$

PKZ150-181200-
South of the AK Peninsula Sitkinak to Castle Cape-
327 PM AKDT Thu Jun 17 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...NE wind 25 kt. Seas 7 ft.
.FRI...NE wind 25 kt. Seas 7 ft.
.FRI NIGHT...NE wind 15 kt. Seas 5 ft.
.SAT...NE wind 15 kt. Seas 4 ft.
.SAT NIGHT...NE wind 30 kt. Seas 9 ft.
.SUN...NW wind 30 kt. Seas 9 ft.
.MON...SE wind 20 kt. Seas 6 ft.
.TUE...SE wind 20 kt. Seas 10 ft.

$$

PKZ155-181200-
South of the AK Peninsula Castle Cape to Cape Sarichef-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...NE wind 20 kt. Seas 6 ft.
.FRI...NE wind 20 kt. Seas 6 ft.
.FRI NIGHT...NE wind 15 kt. Seas 5 ft.
.SAT...NE wind 15 kt. Seas 5 ft.
.SAT NIGHT...N wind 20 kt. Seas 6 ft.
.SUN...W wind 20 kt. Seas 6 ft.
.MON THROUGH TUE...E wind 20 kt. Seas 8 ft.

$$

PKZ160-181200-
Bristol Bay-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...NE wind 15 kt. Seas 1 foot.
.FRI...NE wind 20 kt. Seas 2 ft.
.FRI NIGHT...NE wind 15 kt becoming E after midnight. Seas 2 ft.
.SAT AND SAT NIGHT...N wind 15 kt. Seas 1 foot.
.SUN...N wind 15 kt. Seas 2 ft.
.MON...SE wind 20 kt. Seas 2 ft.
.TUE...E wind 25 kt. Seas 5 ft.

$$

PKZ165-181200-
Port Heiden to Cape Sarichef-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...E wind 20 kt. Seas 3 ft.
.FRI...NE wind 20 kt. Seas 3 ft.
.FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT AND SAT NIGHT...N wind 15 kt. Seas 2 ft.
.SUN...Variable wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...E wind 20 kt. Seas 5 ft.

$$

PKZ170-181200-
Cape Sarichef to Nikolski Bering Side-
327 PM AKDT Thu Jun 17 2021

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt. Seas 6 ft.
.FRI...NE wind 20 kt. Seas 4 ft.
.FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 3 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN THROUGH TUE...E wind 15 kt. Seas 3 ft.

$$

PKZ171-181200-
Unalaska Bay-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...E wind 20 kt. Seas 3 ft.
.FRI...SE wind 10 kt becoming N in the afternoon. Seas 2 ft.
.FRI NIGHT...N wind 10 kt. Seas 2 ft.
.SAT...N wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 1 foot.
.SUN THROUGH TUE...E wind 10 kt. Seas 2 ft.

$$

PKZ172-181200-
Cape Sarichef to Nikolski Pacific Side-
327 PM AKDT Thu Jun 17 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...E wind 25 kt. Seas 8 ft.
.FRI...NE wind 25 kt. Seas 7 ft.
.FRI NIGHT...NE wind 20 kt. Seas 6 ft.
.SAT...NE wind 15 kt. Seas 5 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 5 ft.
.SUN THROUGH TUE...E wind 15 kt. Seas 6 ft.

$$

PKZ173-181200-
Nikolski to Seguam Island Bering Side-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...E wind 20 kt. Seas 5 ft.
.FRI...NE wind 20 kt. Seas 5 ft.
.FRI NIGHT...NE wind 15 kt. Seas 4 ft.
.SAT...E wind 15 kt. Seas 3 ft.
.SAT NIGHT...SE wind 20 kt. Seas 3 ft.
.SUN...E wind 30 kt. Seas 5 ft.
.MON...E wind 15 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.

$$

PKZ174-181200-
Nikolski to Seguam Island Pacific Side-
327 PM AKDT Thu Jun 17 2021

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

.TONIGHT...E wind 25 kt. Seas 9 ft.
.FRI...NE wind 25 kt. Seas 9 ft.
.FRI NIGHT...NE wind 20 kt. Seas 8 ft.
.SAT...E wind 15 kt. Seas 6 ft.
.SAT NIGHT...SE wind 25 kt. Seas 6 ft.
.SUN...E wind 30 kt. Seas 8 ft.
.MON...E wind 15 kt. Seas 8 ft.
.TUE...Variable wind 10 kt. Seas 7 ft.

$$

PKZ175-181200-
Seguam Island to Adak Bering Side-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...NE wind 20 kt. Seas 5 ft.
.FRI...NE wind 15 kt. Seas 5 ft.
.FRI NIGHT...E wind 15 kt. Seas 4 ft.
.SAT...E wind 25 kt. Seas 4 ft.
.SAT NIGHT...SE wind 30 kt. Seas 7 ft.
.SUN...E wind 30 kt. Seas 7 ft.
.MON...E wind 15 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 3 ft.

$$

PKZ176-181200-
Seguam Island to Adak Pacific Side-
327 PM AKDT Thu Jun 17 2021

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...NE wind 25 kt. Seas 7 ft.
.FRI...NE wind 20 kt. Seas 8 ft.
.FRI NIGHT...NE wind 15 kt. Seas 7 ft.
.SAT...SE wind 25 kt. Seas 7 ft.
.SAT NIGHT...SE wind 30 kt. Seas 10 ft.
.SUN...E wind 30 kt. Seas 10 ft.
.MON...Variable wind 10 kt. Seas 8 ft.
.TUE...Variable wind 10 kt. Seas 6 ft.

$$

PKZ177-181200-
Adak to Kiska-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...N wind 20 kt. Seas 5 ft.
.FRI...NE wind 15 kt. Seas 5 ft.
.FRI NIGHT...Variable wind 10 kt becoming SE 20 kt after midnight.
Seas 6 ft.
.SAT AND SAT NIGHT...SE wind 30 kt. Seas 10 ft.
.SUN...SE wind 30 kt. Seas 9 ft.
.MON...Variable wind 10 kt. Seas 8 ft.
.TUE...NW wind 15 kt. Seas 5 ft.

$$

PKZ178-181200-
Kiska to Attu-
327 PM AKDT Thu Jun 17 2021

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...NE wind 15 kt. Seas 4 ft. Patchy fog.
.FRI...E wind 20 kt. Seas 5 ft. Patchy fog.
.FRI NIGHT...E wind 25 kt. Seas 6 ft. Patchy fog.
.SAT...E wind 40 kt. Seas 13 ft.
.SAT NIGHT...SE wind 35 kt. Seas 14 ft.
.SUN...SW wind 30 kt. Seas 11 ft.
.MON THROUGH TUE...NW wind 20 kt. Seas 8 ft.

$$

PKZ179-181200-
Pribilof Islands Near Shore Waters-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...E wind 15 kt. Seas 3 ft.
.FRI...Variable wind 10 kt. Seas 3 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 2 ft.
.SAT AND SAT NIGHT...Variable wind 10 kt. Seas 2 ft.
.SUN...Variable wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...NE wind 15 kt. Seas 4 ft.

$$

PKZ180-181200-
Kuskokwim Delta and Etolin Strait-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...NE wind 15 kt. Seas 2 ft.
.FRI...NE wind 15 kt. Seas 2 ft.
.FRI NIGHT...N wind 15 kt. Seas 2 ft.
.SAT...NE wind 15 kt. Seas 2 ft.
.SAT NIGHT...N wind 20 kt. Seas 2 ft.
.SUN...N wind 15 kt. Seas 2 ft.
.MON...E wind 15 kt. Seas 3 ft.
.TUE...E wind 20 kt. Seas 5 ft.

$$

PKZ181-181200-
North and West of Nunivak Island-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...N wind 20 kt. Seas 3 ft.
.FRI...NE wind 15 kt. Seas 3 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 2 ft.
.SAT AND SAT NIGHT...N wind 15 kt. Seas 3 ft.
.SUN...N wind 15 kt. Seas 2 ft.
.MON THROUGH TUE...NE wind 15 kt. Seas 3 ft.

$$

PKZ185-181200-
Saint Matthew Island Waters-
327 PM AKDT Thu Jun 17 2021

.TONIGHT...Variable wind 10 kt. Seas 2 ft.
.FRI...NE wind 15 kt E of Saint Matthew Island... variable 10 kt W
of Saint Matthew Island. Seas 3 ft.
.FRI NIGHT...NE wind 15 kt. Seas 3 ft.
.SAT AND SAT NIGHT...E wind 15 kt. Seas 3 ft.
.SUN...NE wind 15 kt. Seas 4 ft.
.MON THROUGH TUE...NE wind 20 kt. Seas 6 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
442 PM AKDT Wed Jun 16 2021

.ANALYSIS AND UPPER LEVELS...

An upper level ridge is centered over northern Alaska/Northwest
Canada, with a spoke of the ridge extending southwestward into
Southwest Alaska. The thermal trough and axis of maximum
instability extends across the Alaska Interior then down across
the Kuskokwim Valley. Meanwhile, a short-wave trough is centered
over the Gulf, with its primary trough axis extending eastward to
Southeast Alaska. Along the northern periphery of the upper level
cyclonic circulation, weak waves are tracking westward across
Southcentral Alaska, leading to extensive cloud cover and areas of
light rain or rain showers. Some showers are crossing the Alaska
Range into the Kuskokwim Valley, while others are forming along
the thermal trough. Sunny skies dominate as you head south and
west from here to Bristol Bay, the Kuskokwim Delta and the far
Eastern Bering Sea.

Out west, a mature low south of the Eastern Aleutians is tracking
southward into the Pacific, with rain and winds diminishing
behind it. A low is deepening along the subtropical jet over the
North Pacific to the south of the Aleutian chain, but impacts from
this have not reached the Aleutians. For most of the Bering Sea
and Aleutians weather is currently benign with lots of low clouds,
which is typical for this time of year.

&&

.MODEL DISCUSSION...

Models continue to struggle with the precipitation forecast across
Southcentral and Southwest Alaska as weak and disorganized upper
level impulses track westward across the region. There is better
agreement on a more amplified trough crossing Southcentral
tonight through Thursday morning, then continuing into Southwest
Alaska. Thus, have updated forecasts to reflect an area of steady
rain ahead of this trough. While rain is most likely over inland
areas of Southcentral, there is still some question about how far
south the rain will extend. Notably, Anchorage will be on the
southern periphery of the rain. Looking out through Friday, models
have a good handle on large scale features. The pattern remains
relatively complex, so do expect at least some minor changes to
the forecast each day.

&&

.AVIATION...

PANC...While there may be some fluctuations in the strength of
winds, generally expect gusty southeasterly winds to persist
through Thursday as the surface ridge along the coast remains
firmly in place. Periods of sprinkles or very light rain will
continue through early Thursday, though ceilings are expected to
remain VFR. Steady rain is expected to develop north of Anchorage
as a more significant short-wave trough approaches. If this were
to shift just a little bit to the south, then ceilings could drop
below 5000 ft, but would still think conditions would still
remain VFR (above 3000 ft).

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3:
Wednesday afternoon through Saturday)...

Easterly upper level flow will dominate Southcentral through
Thursday morning as several shortwaves bring enhanced chances of
precipitation. The first wave is located over the Northern Gulf
extending into the Copper River Basin this afternoon. This wave
will continue to produce cloudy conditions across most of the area
with a few showers. Additionally, instability exists across the
Talkeetnas where isolated thunderstorms are expected through this
evening. Another shortwave will move out of the Yukon tonight and
bring an area of rain across Southcentral. With stable conditions
tonight the thunderstorms will die off before midnight with
wetting rains likely across most of the area through Thursday
morning including the Anchorage and MATSU valleys. Thursday
afternoon most of the area of will become sunny with drier
conditions expected and an overall nice afternoon. No
thunderstorms are expected Thursday afternoon or evening as the
atmosphere will be stable, however a few lingering showers are
possible over higher elevations especially the Alaskan Range.

A coastal ridge will continue to produce Turnagain winds bending
into west Anchorage through Thursday but will not be quiet as
strong as today and will taper off by Friday morning as the
pressure gradient weakens.

Friday is expected to be another nice summer day for much of
Southcentral with warm conditions and sun mixed with clouds.
A weak shortwave will move across the Copper River Basin into the
Talkeetnas and Susitna Valley on Friday where isolated showers
and thunderstorms are possible Friday afternoon and evening.

Another coastal ridge develops Friday afternoon through Saturday
with the Turnagain winds redeveloping and turning into west
Anchorage. Saturday is expected to be another warm summer day
with chances of showers and perhaps a thunderstorms mainly over
the Copper River Basin and east towards the Susitna Valley.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3:
Wednesday afternoon through Saturday)...

The easterly wave is responsible for scattered to numerous showers
and isolated thunderstorms over the lower Kuskokwim Valley late
this afternoon into tonight, then continuing on across the
Kuskokwim Delta this evening into late tonight. A separate trough
from the Western Gulf will traverse AKPEN westward leading to
another series of rainfall Thursday morning into early Friday
morning. Models bring another upper North Pacific low closer to
AKPEN on Saturday which could generate rainfall for AKPEN and
Bristol Bay area, but will monitor this situation closely for more
updates. Overall, the short term will bring a continual seasonal
wet pattern, increased clouds and cool overnight temperatures
across the region.

&&

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

Strengthening pressure gradients between the exiting low south of
Eastern Aleutians and the onset of the next North Pacific low
tonight will maintain small craft conditions through at least
Thursday night for several Aleutian Islands. Rain and marine-
layered conditions will linger through Thursday night, then
diminishing by Friday morning until a ridge of high pressure
builds through the Southern Bering and Western to Eastern
Aleutians on Friday morning through Saturday morning. This will
lead to an increased low cloud deck across the Bering. By
Saturday morning, a strong Northwest Pacific Low is expected to
trek towards the Western Aleutians between Saturday morning and
Saturday night, and this could bring another round of increased
rainfall and elevated seas. Stay tuned!

&&
.MARINE (Days 3 through 5: Saturday through Monday)...

A deep low will approach the Western Aleutians on Saturday, then
remain somewhere in the vicinity through Saturday. There is an
increasing likelihood that winds will reach gale force near the
low center on Saturday, which would impact the Western Aleutians
coastal waters. While the ultimate track of the low is uncertain,
do expect winds do diminish Saturday night through Sunday.

Meanwhile, a low over the North-Central Pacific will track toward
Kodiak on Saturday. While it largely looks like winds will max
out at small craft advisory levels, there is a chance of a gale
force winds Saturday night, most likely from the Barren Islands
southwestward through Shelikof Strait. Winds will then quickly
diminish Sunday as the low weakens.

&&

.LONG TERM FORECAST (Days 4 through 7: Sunday through Wednesday)...

The overall synoptic pattern during the extended period consists
of a deepening Aleutian Low combined with a building upper level
ridge across the eastern Gulf of Alaska. This is a cloudy and wet
pattern for Southcentral Alaska as this pattern is conducive to
prevailing onshore flow. A series of upper level waves will move
through Southcentral during the extended period which will bring
periods of rain and showers. With respect to atmospheric stability,
the southerly onshore flow and ample cloud cover will make for a
less than favorable environment for afternoon thunderstorms in the
Copper Basin and Susitna Valley. Temperatures will also be cooler
than normal during this period across Southcentral due to the
ample cloud cover.

Out west, the deepening Aleutian Low will bring strong
southeasterly gap winds along the Alaska Peninsula and Eastern
Aleutians Tuesday afternoon. For the Western Bering, widespread
northwesterly winds will allow for ample stratocumulus clouds and
light showers.

&&

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

&&

SYNOPSIS AND MODEL DISCUSSION...SEB
SOUTHCENTRAL ALASKA...RC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
MARINE/LONG TERM...ED