Small Craft Advisory 486, NWS Anchorage, AK

491 
FZAK52 PAFC 222256
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
256 PM AKDT Fri Jun 22 2018

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.

PKZ199-231130-
256 PM AKDT Fri Jun 22 2018
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A 1004 mb low 270 nm northwest of Saint Paul weakens and exits 
the Bering to the northwest Sat afternoon. A front associated with
a 998 mb low moves over the western Aleutians Sat afternoon. The 
low moves 140 nm northwest of Adak at 999 mb Sun afternoon.

$$

PKZ150-231130-
South of the AK Peninsula Sitkinak to Castle Cape-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...Variable wind 10 kt. Seas 3 ft.
.SAT...Variable wind 10 kt. Seas 2 ft.
.SAT NIGHT...Variable wind 10 kt. Seas 4 ft. Patchy fog.
.SUN AND SUN NIGHT...S wind 15 kt. Seas 5 ft.
.MON...SE wind 25 kt. Seas 9 ft.
.TUE THROUGH WED...S wind 15 kt. Seas 8 ft.

$$

PKZ155-231130-
South of the AK Peninsula Castle Cape to Cape Sarichef-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...Variable wind 10 kt. Seas 3 ft.
.SAT...S wind 10 kt. Seas 3 ft. Patchy fog.
.SAT NIGHT...S wind 10 kt. Seas 3 ft. Patchy fog.
.SUN...S wind 15 kt. Seas 4 ft.
.SUN NIGHT...SE wind 25 kt. Seas 7 ft.
.MON...S wind 25 kt. Seas 9 ft.
.TUE THROUGH WED...S wind 15 kt. Seas 8 ft.

$$

PKZ160-231130-
Bristol Bay-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...Variable wind less than 10 kt. Seas 1 foot.
.SAT...Variable wind less than 10 kt. Seas 1 foot.
.SAT NIGHT...W wind 10 kt. Seas 2 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.SUN NIGHT...NE wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...SE wind 20 kt. Seas 3 ft.
.WED...SE wind 15 kt. Seas 4 ft.

$$

PKZ165-231130-
Port Heiden to Cape Sarichef-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...SE wind 15 kt. Seas 3 ft.
.SAT...S wind 10 kt. Seas 3 ft.
.SAT NIGHT...S wind 10 kt. Seas 3 ft. Patchy fog.
.SUN...SE wind 15 kt. Seas 2 ft.
.SUN NIGHT...E wind 20 kt. Seas 4 ft.
.MON...SE wind 20 kt. Seas 4 ft.
.TUE...S wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 4 ft.

$$

PKZ170-231130-
Cape Sarichef to Nikolski Bering Side-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...S wind 15 kt. Seas 3 ft.
.SAT...SW wind 10 kt. Seas 3 ft. Patchy fog.
.SAT NIGHT...S wind 15 kt. Seas 3 ft. Patchy fog. Rain.
.SUN...SE wind 20 kt. Seas 5 ft.
.SUN NIGHT...E wind 25 kt. Seas 6 ft.
.MON...S wind 20 kt. Seas 5 ft.
.TUE...SW wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 4 ft.

$$

PKZ171-231130-
Unalaska Bay-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...S wind 10 kt. Seas 1 foot.
.SAT...SW wind less than 10 kt. Seas 2 ft. Patchy fog.
.SAT NIGHT...S wind less than 10 kt becoming S 10 kt after midnight.
Seas 2 ft. Patchy fog. Rain.
.SUN...SE wind 15 kt. Seas 2 ft.
.SUN NIGHT...SE wind 20 kt. Seas 3 ft.
.MON THROUGH TUE...SW wind 10 kt. Seas 2 ft.
.WED...Variable wind less than 10 kt. Seas 2 ft.

$$

PKZ172-231130-
Cape Sarichef to Nikolski Pacific Side-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...S wind 15 kt. Seas 3 ft.
.SAT...SW wind 15 kt. Seas 4 ft. Patchy fog.
.SAT NIGHT...SW wind 15 kt. Seas 4 ft. Patchy fog. Rain.
.SUN AND SUN NIGHT...SE wind 25 kt. Seas 9 ft.
.MON THROUGH WED...SW wind 15 kt. Seas 9 ft.

$$

PKZ173-231130-
Nikolski to Seguam Island Bering Side-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...W wind 10 kt. Seas 3 ft. Patchy fog.
.SAT...SW wind 10 kt. Seas 3 ft. Patchy fog.
.SAT NIGHT...SE wind 20 kt. Seas 5 ft. Rain.
.SUN...SE wind 25 kt. Seas 8 ft.
.SUN NIGHT...NE wind 20 kt. Seas 7 ft.
.MON THROUGH TUE...SW wind 15 kt. Seas 6 ft.
.WED...Variable wind 10 kt. Seas 4 ft.

$$

PKZ174-231130-
Nikolski to Seguam Island Pacific Side-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY SATURDAY NIGHT...

.TONIGHT...SW wind 15 kt. Seas 5 ft. Patchy fog.
.SAT...SW wind 15 kt. Seas 5 ft. Patchy fog.
.SAT NIGHT...S wind 25 kt. Seas 7 ft. Rain.
.SUN...SE wind 25 kt. Seas 10 ft.
.SUN NIGHT...W wind 15 kt. Seas 9 ft.
.MON...W wind 15 kt. Seas 9 ft.
.TUE...SW wind 20 kt. Seas 7 ft.
.WED...Variable wind 10 kt. Seas 7 ft.

$$

PKZ175-231130-
Seguam Island to Adak Bering Side-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY SATURDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 3 ft. Patchy fog.
.SAT...S wind 15 kt. Seas 3 ft. Patchy fog.
.SAT NIGHT...SE wind 25 kt. Seas 7 ft. Rain.
.SUN...E wind 20 kt. Seas 7 ft.
.SUN NIGHT...E wind 15 kt. Seas 5 ft.
.MON THROUGH TUE...W wind 15 kt. Seas 5 ft.
.WED...Variable wind 10 kt. Seas 4 ft.

$$

PKZ176-231130-
Seguam Island to Adak Pacific Side-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY SATURDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 5 ft. Patchy fog.
.SAT...S wind 20 kt. Seas 5 ft. Patchy fog. Rain.
.SAT NIGHT...SE wind 30 kt. Seas 11 ft. Rain.
.SUN...S wind 25 kt. Seas 11 ft.
.SUN NIGHT...W wind 15 kt. Seas 8 ft.
.MON...W wind 15 kt. Seas 7 ft.
.TUE...W wind 20 kt. Seas 7 ft.
.WED...Variable wind 10 kt. Seas 6 ft.

$$

PKZ177-231130-
Adak to Kiska-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY SATURDAY AND SATURDAY NIGHT...

.TONIGHT...W wind 15 kt. Seas 4 ft. Patchy fog.
.SAT...SE wind 25 kt. Seas 5 ft building to 9 ft in the afternoon.
Rain.
.SAT NIGHT...SE wind 25 kt. Seas 11 ft.
.SUN...S wind 20 kt. Seas 9 ft.
.SUN NIGHT...NW wind 15 kt. Seas 7 ft.
.MON THROUGH WED...NW wind 15 kt. Seas 6 ft.

$$

PKZ178-231130-
Kiska to Attu-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY SATURDAY and SATURDAY NIGHT...

.TONIGHT...SE wind 25 kt. Seas 6 ft.
.SAT...E wind 30 kt. Seas 12 ft. Rain.
.SAT NIGHT...E wind 25 kt. Seas 11 ft.
.SUN AND SUN NIGHT...N wind 20 kt. Seas 8 ft.
.MON...NW wind 15 kt. Seas 7 ft.
.TUE THROUGH WED...Variable wind 10 kt. Seas 7 ft.

$$

PKZ179-231130-
Pribilof Islands Near Shore Waters-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...SE wind 15 kt. Seas 3 ft.
.SAT...S wind 10 kt. Seas 3 ft.
.SAT NIGHT...S wind 10 kt. Seas 3 ft.
.SUN...SE wind 20 kt. Seas 4 ft.
.SUN NIGHT...E wind 15 kt. Seas 6 ft.
.MON...E wind 20 kt. Seas 6 ft.
.TUE...SE wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 3 ft.

$$

PKZ180-231130-
Kuskokwim Delta and Etolin Strait-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...S wind 15 kt. Seas 3 ft.
.SAT...SE wind 15 kt. Seas 3 ft.
.SAT NIGHT...S wind 15 kt. Seas 3 ft.
.SUN AND SUN NIGHT...SE wind 15 kt. Seas 3 ft.
.MON...E wind 20 kt. Seas 5 ft.
.TUE...SE wind 15 kt. Seas 4 ft.
.WED...SE wind 10 kt. Seas 5 ft.

$$

PKZ181-231130-
North and West of Nunivak Island-
256 PM AKDT Fri Jun 22 2018

.TONIGHT...SE wind 20 kt. Seas 4 ft.
.SAT...SE wind 20 kt. Seas 4 ft.
.SAT NIGHT...SE wind 15 kt. Seas 4 ft.
.SUN...SE wind 15 kt. Seas 4 ft.
.SUN NIGHT...Variable wind 10 kt. Seas 2 ft.
.MON THROUGH TUE...E wind 15 kt. Seas 5 ft.
.WED...Variable wind 10 kt. Seas 3 ft.

$$

PKZ185-231130-
Saint Matthew Island Waters-
256 PM AKDT Fri Jun 22 2018

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...S wind 25 kt. Seas 6 ft.
.SAT...SE wind 20 kt. Seas 6 ft.
.SAT NIGHT...S wind 20 kt. Seas 5 ft.
.SUN AND SUN NIGHT...E wind 15 kt. Seas 5 ft.
.MON THROUGH TUE...NE wind 15 kt. Seas 6 ft.
.WED...Variable wind 10 kt. Seas 4 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
455 PM AKDT Thu Jun 21 2018

.ANALYSIS AND UPPER LEVELS...
The long-lived cold upper level low is still lurking in the
eastern Bering Sea today where it has resided for nearly a week.
The upper level ridge that was nosing into the interior of the
state from the Yukon yesterday is a little farther north over the
Brooks Range as the short wave in the northern Gulf pushes into
it. This is keeping the upper level south to southeast flow over
mainland southern Alaska again today.

At the surface there is the main low between Bethel and Norton
Sound with a trough extending out of it across the interior of
the state. This low can be see in the radar data out of Bethel
from early this afternoon.

&&

.MODEL DISCUSSION...
While models continue to be fine on the synoptic scale, the
smaller features are still a bit elusive. In particular, the
movement of the short waves over Southcentral Alaska are not
picked up overly well, even on the higher resolution models, much
more than 6 to 12 hours in advance.

&&

.AVIATION...
PANC...Overall VFR conditions are expected to persist through
Friday. However, there is a chance for a brief MVFR ceiling
overnight into Friday morning as some rain moves through the area.
Some gusty southeast winds will kick in this evening but should
diminish after midnight.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
An upper level short-wave trough over the northern Gulf will
lift northward across Southcentral Alaska tonight through Friday
morning, with showers spreading northward and becoming more
numerous. Strong low level southeast flow will initially limit
precip in the lee of the Kenai and Chugach Mountains, though this
flow will rapidly weaken overnight as the short-wave moves
overhead. The best chance for steadier showers in Anchorage and
the Matanuska Valley looks to be Friday morning as flow shifts to
southerly right behind the upper wave, as weak cyclonic flow
persists aloft.

Conditions will dry out a little bit Friday afternoon in the wake
of the upper wave, with just some scattered convection focused
mainly along the mountains. Saturday will be direr and sunnier as
a weak ridge builds overhead. There will still be enough
instability to produce a few afternoon/evening showers, especially
along interior mountains. Sunday doesn't look to bad either,
though the thermal trough will begin to strengthen across inland
portions of Southcentral, likely leading to an increase in
afternoon/evening showers.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The main driver of the weather over southwest Alaska is the weak
low pressure over the southwest mainland to the weak low over the
eastern Bering Sea. The upper low is anchored over the eastern
Bering Sea keeping the upper level flow out of the southeast
across the region. The upper level and surface low will move to
the Saint Matthew Island area by Friday morning. This will shift
the flow to southwest across the region by Friday evening bringing
a more showery weather regime Friday. The cool moist onshore
southwest flow into the southwest mainland is not very conducive
to increasing the instability. The CAPE becomes slightly elevated
Friday evening along the Kuskokwim Mountains, however, the chances
for thunderstorms remains minimal and we will stick with isolated
in the forecast for the region.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The surface and upper low over the eastern Bering Sea will drift
north over Saint Matthew Island Friday then slowly drift west to
the dateline by late Saturday. The presence of this low will help
to keep the eastern Bering Sea more mixed, thus fog (typically
associated with the Bering Sea high), will be less extensive over
the Bering Sea through Saturday. A north Pacific low is moving
toward the western Aleutians and will be over the Shemya to Adak
region of the Aleutians by Saturday afternoon as a weak 996 to 998
MB low and trough. As the low approaches the western Aleutians
Saturday morning, pre-frontal wind may reach gale force briefly.

&&

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

The long term forecast begins Sunday night with the deterministic
models and ensemble runs in better agreement than 24 hours ago
with the overall synoptic pattern, especially through late
Tuesday. At the upper levels, a 552dm shortwave low will slide
underneath the ridge over eastern Alaska as it comes onshore over
the Alaska Peninsula. Farther west, two shortwaves along the
ALeutians will undercut and phase with the the longwave trough,
keeping persistent cyclonic flow going over the Bering. In
between the two, an upper-level ridge tries to build over the
northern Gulf. However, the ridge quickly shifts east as the
shortwaves rounding the base of the main trough eject along the
AKpen and into southwestern Alaska. The biggest question is
placement of the trough over the Bering after Wednesday and the
timing of these shortwaves moving toward the Alaska mainland.

This all translates to a surface low along the Alaska Panhandle
Sunday evening with a ridge over the northern Gulf. Another
surface low in the southern Bering will push an occluded front
over the eastern Aleutians through late Monday with a secondary
low developing near Kodiak Island brining rain along the AKpen.
Over southern and southwest AK, afternoon and evening showers will
fire up Sunday through Tuesday along a thermal trough draped
across the interior.

The low moves into the northern Gulf for Wednesday, spreading rain
along southern coast with scattered showers continuing for the
interior. It is at this point that the models begin to diverge.
The GFS is still the more progressive solution, pushing the
upper-level trough axis closer to southwest Alaska and building a
ridge over the Western Aleutians. The EC and Canadian favor a
continuation of the broad low over the Bering and the development
of a stronger, second surface low following the track of the
previous for Wednesday night into Thursday. As of right now, and
given the current synoptic pattern, the EC/Canadian is preferred
over the GFS. Either way, next week looks to remain quite
unsettled from the eastern Aleutians to the northern Gulf.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...SA
LONG TERM...TM