Small Craft Advisory 485, NWS Anchorage, AK

199 
FZAK52 PAFC 181155
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
355 AM AKDT Fri Jun 18 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.

PKZ199-190045-
355 AM AKDT Fri Jun 18 2021
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 1014 mb low 25 nm west of Kipnuk moves to 75 nm north of Saint 
Paul for Sat morning before dissipating Sat afternoon. A 982 mb 
low 320 nm southwest of Shemya Sat morning moves to 240 nm west of
Shemya by Sun morning. Its front moves from the western Aleutians
Sat morning to the central Aleutians by Sun morning.

$$

PKZ150-190045-
South of the AK Peninsula Sitkinak to Castle Cape-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...NE wind 25 kt. Seas 6 ft.
.TONIGHT...NE wind 15 kt. Seas 5 ft.
.SAT...NE wind 20 kt. Seas 4 ft.
.SAT NIGHT...NE wind 25 kt. Seas 10 ft.
.SUN...NW wind 25 kt. Seas 9 ft.
.MON...S wind 15 kt. Seas 7 ft.
.TUE...E wind 25 kt. Seas 9 ft.

$$

PKZ155-190045-
South of the AK Peninsula Castle Cape to Cape Sarichef-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 20 kt. Seas 5 ft.
.TONIGHT...NE wind 15 kt. Seas 5 ft.
.SAT...NE wind 20 kt. Seas 6 ft.
.SAT NIGHT...N wind 20 kt. Seas 7 ft.
.SUN...W wind 15 kt. Seas 7 ft.
.MON THROUGH TUE...E wind 15 kt. Seas 8 ft.

$$

PKZ160-190045-
Bristol Bay-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 15 kt. Seas 2 ft.
.TONIGHT...NE wind 15 kt becoming E after midnight. Seas 2 ft.
.SAT...NE wind 10 kt. Seas 1 foot.
.SAT NIGHT...N wind 15 kt. Seas 2 ft.
.SUN...N wind 15 kt. Seas 4 ft.
.MON...S wind 15 kt. Seas 2 ft.
.TUE...E wind 25 kt. Seas 6 ft.

$$

PKZ165-190045-
Port Heiden to Cape Sarichef-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 15 kt. Seas 2 ft.
.TONIGHT...NE wind 15 kt. Seas 3 ft.
.SAT...NE wind 15 kt. Seas 2 ft.
.SAT NIGHT...N wind 15 kt. Seas 2 ft.
.SUN...N wind 15 kt. Seas 2 ft.
.MON...E wind 20 kt. Seas 3 ft.
.TUE...E wind 25 kt. Seas 5 ft.

$$

PKZ170-190045-
Cape Sarichef to Nikolski Bering Side-
355 AM AKDT Fri Jun 18 2021

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

$$

PKZ171-190045-
Unalaska Bay-
355 AM AKDT Fri Jun 18 2021

.TODAY...E wind 10 kt. Seas 2 ft.
.TONIGHT...N wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind less than 10 kt. Seas 1 foot.
.SUN THROUGH TUE...E wind 10 kt. Seas 3 ft.

$$

PKZ172-190045-
Cape Sarichef to Nikolski Pacific Side-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY TODAY...

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

$$

PKZ173-190045-
Nikolski to Seguam Island Bering Side-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 15 kt. Seas 5 ft.
.TONIGHT...NE wind 15 kt. Seas 4 ft.
.SAT...E wind 15 kt. Seas 3 ft.
.SAT NIGHT...SE wind 20 kt. Seas 4 ft.
.SUN...E wind 25 kt. Seas 6 ft.
.MON...E wind 15 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.

$$

PKZ174-190045-
Nikolski to Seguam Island Pacific Side-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY TODAY...

.TODAY...NE wind 25 kt. Seas 8 ft.
.TONIGHT...NE wind 20 kt in the evening diminishing to 10 kt after
midnight. Seas 7 ft.
.SAT...E wind 15 kt. Seas 6 ft.
.SAT NIGHT...SE wind 25 kt. Seas 6 ft.
.SUN...E wind 25 kt. Seas 8 ft.
.MON...E wind 20 kt. Seas 8 ft.
.TUE...Variable wind 10 kt. Seas 7 ft.

$$

PKZ175-190045-
Seguam Island to Adak Bering Side-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY SATURDAY...

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

$$

PKZ176-190045-
Seguam Island to Adak Pacific Side-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY SATURDAY...

.TODAY...NE wind 20 kt. Seas 7 ft.
.TONIGHT...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...SE wind 25 kt. Seas 9 ft.
.MON...S wind 15 kt. Seas 8 ft.
.TUE...Variable wind 10 kt. Seas 7 ft.

$$

PKZ177-190045-
Adak to Kiska-
355 AM AKDT Fri Jun 18 2021

...SMALL CRAFT ADVISORY SATURDAY...

.TODAY...NE wind 15 kt. Seas 5 ft.
.TONIGHT...Variable wind 10 kt becoming SE 20 kt after midnight.
Seas 5 ft.
.SAT...SE wind 30 kt. Seas 9 ft.
.SAT NIGHT...SE wind 30 kt. Seas 11 ft.
.SUN...S wind 25 kt. Seas 9 ft.
.MON...S wind 15 kt. Seas 9 ft.
.TUE...NW wind 20 kt. Seas 5 ft.

$$

PKZ178-190045-
Kiska to Attu-
355 AM AKDT Fri Jun 18 2021

...GALE WARNING SATURDAY...

.TODAY...E wind 20 kt. Seas 4 ft. Patchy fog.
.TONIGHT...E wind 25 kt. Seas 6 ft. Patchy fog.
.SAT...E wind 35 kt. Seas 14 ft. Rain.
.SAT NIGHT...SE wind 35 kt. Seas 13 ft.
.SUN...S wind 30 kt. Seas 12 ft.
.MON...SE wind 15 kt. Seas 10 ft.
.TUE...NW wind 25 kt. Seas 6 ft.

$$

PKZ179-190045-
Pribilof Islands Near Shore Waters-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 10 kt. Seas 2 ft.
.TONIGHT...Variable wind less than 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 1 foot.
.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.

$$

PKZ180-190045-
Kuskokwim Delta and Etolin Strait-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 15 kt diminishing to 10 kt in the afternoon. Seas
2 ft.
.TONIGHT...N wind 10 kt. Seas 2 ft.
.SAT...NE wind 10 kt. Seas 2 ft.
.SAT NIGHT...NW wind 15 kt. Seas 2 ft.
.SUN...NW wind 10 kt. Seas 2 ft.
.MON...SE wind 10 kt. Seas 2 ft.
.TUE...E wind 25 kt. Seas 6 ft.

$$

PKZ181-190045-
North and West of Nunivak Island-
355 AM AKDT Fri Jun 18 2021

.TODAY...N wind 15 kt. Seas 3 ft.
.TONIGHT...N wind 10 kt. Seas 2 ft.
.SAT...N wind 10 kt. Seas 2 ft.
.SAT NIGHT...N wind 15 kt. Seas 2 ft.
.SUN...N wind 15 kt. Seas 2 ft.
.MON...Variable wind 10 kt. Seas 3 ft.
.TUE...NE wind 20 kt. Seas 4 ft.

$$

PKZ185-190045-
Saint Matthew Island Waters-
355 AM AKDT Fri Jun 18 2021

.TODAY...NE wind 15 kt E of Saint Matthew Island... variable 10 kt
W of Saint Matthew Island. Seas 3 ft.
.TONIGHT...Variable wind 10 kt. Seas 2 ft.
.SAT...NE wind 15 kt. Seas 3 ft.
.SAT NIGHT...NE wind 15 kt. Seas 3 ft.
.SUN THROUGH MON...NE wind 15 kt. Seas 5 ft.
.TUE...NE wind 20 kt. Seas 6 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
538 AM AKDT Thu Jun 17 2021

.ANALYSIS AND UPPER LEVELS...

An upper-level ridge extends from northwest Canada across the
northern half of the state. Farther south, an upper-level low
remains nearly stationary over the western Gulf with a trough
extending northeast across the Gulf toward Yakutat. Between these
two main features, an easterly flow persists across the southern
Mainland. A series of shortwaves is embedded within this flow.
The more potent of these waves has moved into the interior of the
state with shower activity continuing overnight and into the early
morning hours from along the Alaska Range west over the Kuskokwim
Mountains and YK-Delta. Shower activity is also occurring along
coastal Bristol Bay this morning as a second wave moves over the
AKPEN. Extensive cloud cover also remains across much of the
state in association with these waves.

Farther west, a ridge is situated over the eastern Bering. A
layer of low stratus and fog is developing within the more stable
airmass, and a light southeasterly flow is advecting the fog and
low cloud deck to the Pribilof Islands this morning. Elsewhere, a
weak upper-level wave is lifting north and exiting the Bering with
a second ridge parked over the western Bering and Aleutians. A
993 mb North Pacific low is south of Adak. This feature is
extending a cloud shield across the central Aleutians this
morning.

&&

.MODEL DISCUSSION...

Models are coming into to better agreement on the timing and
track of a more amplified easterly shortwave moving from
Southcentral this morning to Southwest Alaska by this evening.
There is also better agreement with a secondary easterly wave
moving into the Copper River Basin for Friday morning then
tracking west to the Southwest interior of the state by late
Friday. The NAM, however, does advertise a more northerly track
with this feature, moving it westward just north of the Alaska
Range due to the influence of yet another wave in the Gulf.

It is this third wave where more model uncertainty creeps into
the picture. This concerns the track of an upper-level wave
lifting from the North Pacific to the eastern Gulf for Friday. The
00z and 06z NAM runs continue to push this feature farther north
and west, placing it over the northwestern Gulf by late Friday.
The 00z runs of the GFS and GEM continue a more northerly track,
moving it onshore near Yakutat over the eastern Gulf with the EC
pushing it closer to the Alaska Panhandle. The 06z GFS solution is
trending closer to the most recent NAM run, though. If the NAM
solution holds, it would mean a wider expanse of rain and stronger
easterly winds along the northern and western Gulf coast for the
weekend.

&&

.AVIATION...
PANC...The Turnagain Arm/SE winds will be the most challenging
aspect to this TAF package. They will likely ebb and flow as they
gradually weaken through the day. Ceilings and visibility will
remain VFR.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 through 3...Thu
through Sat)...The pattern will be rather dynamic over the next
couple days, especially for this time of year. The main weather
makers will continue to be waves of energy traveling from east to
west ("easterly waves"). The first of these moved through Wed
afternoon and the next one is currently sliding off the Talkeetna
Mountains. This will keep cloud cover widespread across the area
this morning, with the best chances over the northern half of the
Susitna Valley and the North Gulf Coast. As the wave exits the
area later this afternoon, it will leave a cool and stable airmass
in its wake. This will inhibit any convective development and
allowing a brief period of drying to ensue.

For Friday, most areas will see a dry day as some weak mid-
level ridging pushes over the area from the east. There will still
be a fair amount of cloud cover which will limit high temperatures
to the mid-60s to low 70s. Another easterly wave will slide into
the Copper River Basin and the AK Range during the afternoon and
evening. This will trigger another round of convection, with
widespread showers and a slight chance of thunderstorms in the
mountains. Some southeasterly gap winds are also expected ahead of
this wave, especially through the typical areas of the Turnagain
Arm and the Knik/Copper River Valleys.

Saturday will start to see the upper levels transition while much
of the sensible weather remains similar to Friday. Expect south to
southeast flow to continue to bring some gusty gap winds and a
healthy amount of cloud cover. We anticipate there will be enough
instability for another round of afternoon convection, especially
along the mountains over the Copper River Basin. We have held off
on including any mention of thunderstorms at this point as we wait
for the models to get a better handle on the next series of waves.

&&

&&

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

Easterly flow aloft in tandem with an upper level trough and
associated low over the western Gulf will bring series of
shortwaves tracking across the Alaska Range as well north of AKPEN
into the forecast area. Today through Saturday, the resultant
weather will be cooler temperatures with increasing cloudiness and
steady rain moving into the Middle Kuskokwim Valley and spreading
westward over coastal areas of Bristol Bay and the Y-K Delta.
Moisture associated with the aforementioned western Gulf low will
also provide chances of rain over the southern AKPEN in the next
couple of days.

&&

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

A combination of a weakening low south of Sand Point and an
approaching low moving south of the western Aleutians will help
maintain easterly gap winds across much of the Chain through
Friday morning. As the two lows exits the forecast area, a weak
ridge of high pressure aloft will build over the Bering and help
maintain area of low clouds and fog from Friday through Saturday
morning. Thereafter, a well-developed low will approach the
western Aleutians on Saturday morning with increasing chances of
rain and the potential of low end gale force winds near the low
center.

&&

.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...TM
SOUTHCENTRAL ALASKA...MSO
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...MF
MARINE/LONG TERM...ED