Small Craft Advisory 571, NWS Anchorage, AK

725 
FZAK52 PAFC 052352
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
352 PM AKDT Sat Aug 5 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.

PKZ199-061245-
352 PM AKDT Sat Aug 5 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 1002 mb low 140 nm south of Cold Bay slowly moves southward 
into the north Pacific by Mon morning. The associated front 
remains nearly stationary over the eastern Aleutians/Bering and 
Alaska Peninsula through Mon. A 1008 mb low east of Kamchatka Sun
moves 240 nm north of Shemya at 1003 mb by Mon afternoon. The 
associated front tracks into the western Bering/Aleutians by Sun 
morning, then into the central Bering/Aleutians by Mon morning.

$$

PKZ150-061245-
South of the AK Peninsula Sitkinak to Castle Cape-
352 PM AKDT Sat Aug 5 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt. Seas 9 ft. Rain.
.SUN...E wind 20 kt. Seas 6 ft. Rain.
.SUN NIGHT...E wind 15 kt. Seas 6 ft. Rain.
.MON AND MON NIGHT...SE wind 15 kt. Seas 5 ft.
.TUE...E wind 20 kt. Seas 6 ft.
.WED...S wind 15 kt. Seas 5 ft.
.THU...E wind 15 kt. Seas 5 ft.

$$

PKZ155-061245-
South of the AK Peninsula Castle Cape to Cape Sarichef-
352 PM AKDT Sat Aug 5 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt diminishing to 15 kt after midnight. Seas
7 ft. Periods of rain.
.SUN...NE wind 20 kt. Seas 6 ft.
.SUN NIGHT...NE wind 15 kt. Seas 6 ft. Patchy fog.
.MON AND MON NIGHT...Variable wind 10 kt. Seas 5 ft.
.TUE...E wind 20 kt. Seas 4 ft.
.WED...S wind 15 kt. Seas 5 ft.
.THU...Variable wind 10 kt. Seas 4 ft.

$$

PKZ160-061245-
Bristol Bay-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...E wind 20 kt. Seas 4 ft.
.SUN...E wind 15 kt. Seas 3 ft.
.SUN NIGHT...NE wind 15 kt becoming E after midnight. Seas 2 ft.
Patchy fog.
.MON...E wind 10 kt. Seas 2 ft.
.MON NIGHT...E wind 15 kt. Seas 2 ft.
.TUE...E wind 15 kt. Seas 2 ft.
.WED THROUGH THU...E wind 10 kt. Seas 3 ft.

$$

PKZ165-061245-
Port Heiden to Cape Sarichef-
352 PM AKDT Sat Aug 5 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NE wind 25 kt. Seas 7 ft.
.SUN...NE wind 20 kt. Seas 6 ft. Patchy fog.
.SUN NIGHT...NE wind 20 kt. Seas 4 ft. Areas of fog.
.MON...Variable wind 10 kt. Seas 3 ft.
.MON NIGHT...Variable wind 10 kt. Seas 2 ft.
.TUE...E wind 15 kt. Seas 2 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.THU...Variable wind 10 kt. Seas 3 ft.

$$

PKZ170-061245-
Cape Sarichef to Nikolski Bering Side-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt. Seas 6 ft. Patchy fog.
.SUN...N wind 20 kt. Seas 7 ft. Patchy fog.
.SUN NIGHT...N wind 15 kt. Seas 6 ft. Areas of fog.
.MON...Variable wind 10 kt. Seas 3 ft.
.MON NIGHT...Variable wind 10 kt. Seas 2 ft.
.TUE...Variable wind 10 kt. Seas 2 ft.
.WED...Variable wind 10 kt. Seas 3 ft.
.THU...Variable wind 10 kt. Seas 2 ft.

$$

PKZ171-061245-
Unalaska Bay-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 15 kt. Seas 5 ft. Patchy fog.
.SUN...N wind 15 kt. Seas 5 ft. Patchy fog.
.SUN NIGHT...N wind 10 kt. Seas 3 ft. Areas of fog.
.MON...N wind 10 kt. Seas 3 ft.
.MON NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.TUE...Variable wind less than 10 kt. Seas 1 foot.
.WED...Variable wind less than 10 kt. Seas 1 foot.
.THU...Variable wind less than 10 kt. Seas 1 foot.

$$

PKZ172-061245-
Cape Sarichef to Nikolski Pacific Side-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt. Seas 6 ft. Patchy fog.
.SUN...N wind 20 kt. Seas 6 ft. Patchy fog.
.SUN NIGHT...N wind 20 kt. Seas 6 ft. Patchy fog.
.MON...N wind 15 kt. Seas 5 ft.
.MON NIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...Variable wind 10 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 5 ft.

$$

PKZ173-061245-
Nikloski to Seguam Island Bering Side-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt. Seas 5 ft. Patchy fog.
.SUN...N wind 20 kt. Seas 7 ft. Patchy fog.
.SUN NIGHT...N wind 20 kt. Seas 6 ft. Areas of fog.
.MON...Variable wind 10 kt. Seas 5 ft.
.MON NIGHT...Variable wind 10 kt. Seas 3 ft.
.TUE...S wind 15 kt. Seas 3 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 4 ft.

$$

PKZ174-061245-
Nikolski to Seguam Island Pacific Side-
352 PM AKDT Sat Aug 5 2017

...SMALL CRAFT ADVISORY THROUGH SUNDAY...

.TONIGHT...NW wind 25 kt. Seas 6 ft.
.SUN...N wind 25 kt. Seas 7 ft.
.SUN NIGHT...N wind 20 kt. Seas 7 ft. Patchy fog.
.MON...NW wind 15 kt. Seas 5 ft.
.MON NIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...S wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 5 ft.

$$

PKZ175-061245-
Seguam Island to Adak Bering Side-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt. Seas 5 ft. Patchy fog.
.SUN...N wind 20 kt. Seas 5 ft. Patchy fog.
.SUN NIGHT...N wind 20 kt. Seas 5 ft. Patchy fog.
.MON...W wind 15 kt. Seas 5 ft.
.MON NIGHT...S wind 20 kt. Seas 3 ft.
.TUE...SW wind 15 kt. Seas 4 ft.
.WED...NE wind 15 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 3 ft.

$$

PKZ176-061245-
Seguam Island to Adak Pacific Side-
352 PM AKDT Sat Aug 5 2017

...SMALL CRAFT ADVISORY SUNDAY...

.TONIGHT...NW wind 20 kt. Seas 6 ft. Patchy fog.
.SUN...N wind 25 kt. Seas 6 ft.
.SUN NIGHT...N wind 20 kt. Seas 6 ft. Patchy fog.
.MON...NW wind 15 kt. Seas 5 ft.
.MON NIGHT...S wind 15 kt. Seas 4 ft.
.TUE...SW wind 15 kt. Seas 4 ft.
.WED...Variable wind 10 kt. Seas 4 ft.
.THU...Variable wind 10 kt. Seas 4 ft.

$$

PKZ177-061245-
Adak to Kiska-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...NW wind 20 kt. Seas 5 ft. Areas of fog.
.SUN...N wind 15 kt. Seas 4 ft. Patchy fog.
.SUN NIGHT...SW wind 15 kt. Seas 4 ft. Areas of fog.
.MON...SW wind 15 kt. Seas 4 ft.
.MON NIGHT...W wind 15 kt. Seas 5 ft.
.TUE...Variable wind 10 kt. Seas 5 ft.
.WED THROUGH THU...NE wind 15 kt. Seas 5 ft.

$$

PKZ178-061245-
Kiska to Attu-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...Variable wind 10 kt. Seas 4 ft. Areas of fog.
.SUN...SW wind 15 kt. Seas 4 ft. Areas of fog.
.SUN NIGHT...SW wind 15 kt. Seas 6 ft. Areas of fog. Rain.
.MON AND MON NIGHT...NW wind 15 kt. Seas 6 ft.
.TUE...NW wind 15 kt. Seas 6 ft.
.WED THROUGH THU...NE wind 15 kt. Seas 5 ft.

$$

PKZ179-061245-
Pribilof Islands Near Shore Waters-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...NE wind 20 kt. Seas 5 ft. Areas of fog.
.SUN...N wind 20 kt. Seas 5 ft. Areas of fog.
.SUN NIGHT...N wind 10 kt. Seas 4 ft. Areas of fog.
.MON...Variable wind 10 kt. Seas 2 ft.
.MON NIGHT...Variable wind 10 kt. Seas 2 ft.
.TUE...E wind 15 kt. Seas 4 ft.
.WED THROUGH THU...Variable wind 10 kt. Seas 4 ft.

$$

PKZ180-061245-
Kuskokwim Delta and Etolin Strait-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...NE wind 20 kt. Seas 5 ft. Patchy fog.
.SUN...NE wind 15 kt. Seas 4 ft. Patchy fog.
.SUN NIGHT...NW wind 15 kt. Seas 3 ft. Areas of fog.
.MON...S wind 10 kt. Seas 2 ft.
.MON NIGHT...SE wind 10 kt. Seas 2 ft.
.TUE...E wind 15 kt. Seas 2 ft.
.WED...E wind 10 kt. Seas 3 ft.
.THU...N wind 10 kt. Seas 2 ft.

$$

PKZ181-061245-
North and West of Nunivak Island-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt. Seas 4 ft. Areas of fog.
.SUN...N wind 20 kt. Seas 5 ft. Areas of fog.
.SUN NIGHT...N wind 20 kt. Seas 4 ft. Areas of fog.
.MON...Variable wind 10 kt. Seas 3 ft.
.MON NIGHT...Variable wind 10 kt. Seas 2 ft.
.TUE...Variable wind 10 kt. Seas 3 ft.
.WED THROUGH THU...Variable wind 10 kt. Seas 4 ft.

$$

PKZ185-061245-
Saint Matthew Island Waters-
352 PM AKDT Sat Aug 5 2017

.TONIGHT...N wind 20 kt E of Saint Matthew Island...E 10 kt W of 
Saint Matthew Island. Seas 4 ft. Areas of fog.
.SUN...NE wind 20 kt. Seas 4 ft. Areas of fog.
.SUN NIGHT...Ne wind 15 kt E of Saint Matthew Island...SW 15 kt W of
Saint Matthew Island. Seas 4 ft. Patchy fog.
.MON...SE wind 15 kt. Seas 4 ft.
.MON NIGHT...E wind 15 kt. Seas 4 ft.
.TUE...E wind 15 kt. Seas 5 ft.
.WED THROUGH THU...Variable wind 10 kt. Seas 4 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
427 PM AKDT Fri Aug 4 2017

.ANALYSIS AND UPPER LEVELS...
The frontal boundary that brought widespread rain and clouds to
much of Southwest Alaska and Southcentral on Thu is being pushed
north and west as a high pressure builds northwest from the Gulf.
Satellite imagery shows a frontal band over the western Alaska
Peninsula and another weaker band and surface low approaching the
western Gulf and central Ak Pen from the south. Widespread
stratus under the strengthening ridge is evident over much of the
Gulf and North Coast. Cloud breaks are developing inland across
Southcentral with the building ridge.

&&

.MODEL DISCUSSION...
Models are in relatively good agreement with the synoptic
features through the weekend. Higher res models will be used in
part to capture the mesoscale influences.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Southcentral Alaska continues to have a negative tilted ridge
building over the region extending through the Panhandle. This
synoptic feature looks to maintain through the the weekend.
Therefore, look for high temperatures in the 70s through majority
of the Southcentral. While the warmest temperatures will be in the
lower 80s in the Susitna valley and Copper River Basin for
Saturday before dropping into the mid 70s by Sunday. A thermal
trough looks to be located just north of the Alaska Range by
Sunday afternoon/evening. Therefore, there is a slight chance for
thunderstorms to develop along the Talkeetna Mountains, and the
Alaska Range. Meanwhile, by Sunday morning the flow in the Cook
Inlet will shift to more southwesterly, and will push the marine
layer stratus/fog up the Inlet into the Anchorage Bowl by Sunday
morning. The challenge will be how dense the fog and stratus
develops with this southwesterly flow, and the ridge overhead. For
Kodiak, a continued decaying front remains through the weekend.
The wind flow remains east to southeast flow off the Gulf, and the
marine layer stratus/fog remains parked over the lower
Southwestern Gulf producing cool and cloudy conditions.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
Southwest Alaska remains sandwiched in between a longwave trough
containing a large upper low over the Bering/North Pacific and a
ridge over the Mainland. Between the two features, southeasterly
flow will continue over the area tonight and shift to easterly
offshore flow Saturday night as the upper low departs to the
south. This shift in winds will support a warming and drying trend
through the weekend. As the ridge noses in from the Interior, a
thermal trough will develop, allowing for low-level instability to
increase. This will support some isolated thunderstorms Sunday
along the Alaska Range, Kilbuck Mountains, and Kuskokwim Delta
area. Upper- level forcing is weak, however if any disturbances
develop within the cyclonic flow, thunderstorms could become more
widespread.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The broad low over the Bering at the base of the longwave trough
will continue to slowly shift southward tonight, crossing the
Aleutians this evening and moving into the North Pacific by
Saturday. As the low departs the Bering, ridging will build over
the western Aleutians and western Bering. Warm air advection in
this area will continue to create a strong inversion, trapping the
marine layer at or just above the surface. Fog and low stratus
will persist for the next few days over the Bering with the
thickest fog over the western Bering and western Aleutians.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Beginning the extended forecast period Monday, there will be a
large closed low south of the Alaska Peninsula with an eastward
moving ridge axis centered over the Yukon. Clouds will be on the
increase across all of Southern Alaska as difluent upper level
flow associated with the NPAC trough will be moving northward.
This will support coastal rain and some inland showers, although
Monday will generally be a decent day across inland areas,
especially Southcentral. Thereafter, the upper trough will begin
to lift north and spread more rain into Southern Alaska,
especially Wednesday and beyond as a series of Arctic troughs dig
through the Bering Sea and reinforce the NPAC trough. Currently
there is some discrepancy among the GFS and ECMWF on exactly when
the rain chances increases as the GFS is more bullish lifting the
trough northward. Either way, by late Tue into Wednesday expect
cooling temps and increasing threats for rain which will last
through the remainder of the week.

&&

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

&&

SYNOPSIS AND MODEL DISCUSSION...RC
SOUTHCENTRAL ALASKA...PD
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RD
LONG TERM...Ahsenmacher