Small Craft Advisory 702, NWS Anchorage, AK

191 
FZAK52 PAFC 202308
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
308 PM AKDT Wed Sep 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.

PKZ199-211145-
308 PM AKDT Wed Sep 20 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 986 mb low 240 nm south of Adak moves to 210 nm southwest of 
Dutch Harbor at 998 mb Thu evening moving eastward becoming 
complex through Fri. The associated front moves over the Eastern 
Aleutians and the Alaska Peninsula Thu evening then will move into
the western Gulf Fri afternoon.

$$

PKZ150-211145-
South of the AK Peninsula Sitkinak to Castle Cape-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SE wind 25 kt. Seas 8 ft. Rain.
.THU...S wind 25 kt. Seas 10 ft.
.THU NIGHT...SW wind 25 kt. Seas 10 ft.
.FRI...S wind 20 kt. Seas 9 ft.
.FRI NIGHT...S wind 25 kt. Seas 10 ft.
.SAT...SW wind 20 kt. Seas 10 ft.
.SUN...W wind 25 kt. Seas 9 ft.
.MON...W wind 20 kt. Seas 8 ft.

$$

PKZ155-211145-
South of the AK Peninsula Castle Cape to Cape Sarichef-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...S wind 25 kt. Seas 10 ft.
.THU...S wind 25 kt. Seas 10 ft.
.THU NIGHT...S wind 25 kt. Seas 11 ft.
.FRI...S wind 20 kt. Seas 10 ft.
.FRI NIGHT...SW wind 20 kt. Seas 10 ft.
.SAT...NW wind 20 kt. Seas 8 ft.
.SUN...W wind 25 kt. Seas 8 ft.
.MON...W wind 20 kt. Seas 7 ft.

$$

PKZ160-211145-
Bristol Bay-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt. Seas 4 ft. Rain.
.THU...SE wind 20 kt becoming S 10 kt in the afternoon. Seas 3 ft.
.THU NIGHT...S wind 20 kt. Seas 3 ft. Rain.
.FRI AND FRI NIGHT...E wind 20 kt. Seas 4 ft.
.SAT...N wind 15 kt. Seas 3 ft.
.SUN THROUGH MON...W wind 20 kt. Seas 4 ft.

$$

PKZ165-211145-
Port Heiden to Cape Sarichef-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...E wind 25 kt becoming S 15 kt after midnight. Seas 5 ft.
.THU...S wind 15 kt. Seas 3 ft.
.THU NIGHT...S wind 20 kt. Seas 4 ft. Rain.
.FRI...SE wind 20 kt. Seas 5 ft.
.FRI NIGHT...NW wind 20 kt. Seas 8 ft.
.SAT...NW wind 25 kt. Seas 8 ft.
.SUN THROUGH MON...W wind 20 kt. Seas 6 ft.

$$

PKZ170-211145-
Cape Sarichef to Nikolski Bering Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THURSDAY NIGHT...

.TONIGHT...S wind 20 kt. Seas 6 ft.
.THU...E wind 15 kt. Seas 4 ft. Rain.
.THU NIGHT...E wind 20 kt becoming N 30 kt after midnight. Seas 5
ft building to 9 ft. Rain.
.FRI AND FRI NIGHT...NW wind 25 kt. Seas 10 ft.
.SAT THROUGH MON...NW wind 20 kt. Seas 8 ft.

$$

PKZ171-211145-
Unalaska Bay-
308 PM AKDT Wed Sep 20 2017

.TONIGHT...S wind 10 kt. Seas 2 ft. Rain.
.THU...SE wind 10 kt. Seas 2 ft. Rain.
.THU NIGHT...S wind 10 kt in the evening becoming variable less
than 10 kt. Seas 3 ft. Rain.
.FRI AND FRI NIGHT...NW wind 20 kt. Seas 7 ft.
.SAT...NW wind 15 kt. Seas 5 ft.
.SUN...NW wind 20 kt. Seas 2 ft.
.MON...W wind 15 kt. Seas 2 ft.

$$

PKZ172-211145-
Cape Sarichef to Nikolski Pacific Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...S wind 15 kt. Seas 11 ft. Rain.
.THU AND THU NIGHT...S wind 25 kt. Seas 10 ft. Rain.
.FRI AND FRI NIGHT...NW wind 25 kt. Seas 9 ft.
.SAT THROUGH MON...NW wind 20 kt. Seas 8 ft.

$$

PKZ173-211145-
Nikloski to Seguam Island Bering Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...S wind 15 kt becoming E 20 kt after midnight. Seas 9 ft.
.THU...NE wind 25 kt. Seas 9 ft.
.THU NIGHT...N wind 30 kt. Seas 13 ft.
.FRI AND FRI NIGHT...N wind 25 kt. Seas 12 ft.
.SAT THROUGH MON...NW wind 20 kt. Seas 8 ft.

$$

PKZ174-211145-
Nikolski to Seguam Island Pacific Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...SE wind 20 kt. Seas 10 ft.
.THU...SE wind 15 kt. Seas 9 ft. Rain.
.THU NIGHT...N wind 30 kt. Seas 11 ft. Rain.
.FRI...N wind 30 kt. Seas 12 ft.
.FRI NIGHT...N wind 25 kt. Seas 9 ft.
.SAT...NW wind 20 kt. Seas 9 ft.
.SUN...NW wind 25 kt. Seas 9 ft.
.MON...NW wind 20 kt. Seas 7 ft.

$$

PKZ175-211145-
Seguam Island to Adak Bering Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 20 kt. Seas 9 ft.
.THU...NE wind 30 kt. Seas 12 ft.
.THU NIGHT...N wind 30 kt. Seas 13 ft.
.FRI AND FRI NIGHT...N wind 25 kt. Seas 11 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 8 ft.
.MON...NW wind 15 kt. Seas 6 ft.

$$

PKZ176-211145-
Seguam Island to Adak Pacific Side-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...E wind 20 kt. Seas 10 ft. Rain.
.THU...N wind 25 kt. Seas 9 ft.
.THU NIGHT...N wind 25 kt. Seas 10 ft.
.FRI...N wind 25 kt. Seas 9 ft.
.FRI NIGHT...N wind 20 kt. Seas 7 ft.
.SAT THROUGH SUN...NW wind 20 kt. Seas 6 ft.
.MON...NW wind 15 kt. Seas 5 ft.

$$

PKZ177-211145-
Adak to Kiska-
308 PM AKDT Wed Sep 20 2017

...GALE WARNING TONIGHT...

.TONIGHT...NE wind 35 kt. Seas 15 ft.
.THU...N wind 30 kt. Seas 14 ft.
.THU NIGHT...N wind 25 kt. Seas 13 ft.
.FRI...NE wind 20 kt. Seas 10 ft.
.FRI NIGHT...N wind 15 kt. Seas 8 ft.
.SAT THROUGH MON...NW wind 15 kt. Seas 6 ft.

$$

PKZ178-211145-
Kiska to Attu-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...N wind 30 kt. Seas 13 ft.
.THU...N wind 30 kt. Seas 13 ft.
.THU NIGHT...NE wind 20 kt. Seas 12 ft.
.FRI...NE wind 15 kt. Seas 9 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 7 ft.
.SAT...Variable wind 10 kt. Seas 6 ft.
.SUN THROUGH MON...W wind 15 kt. Seas 5 ft.

$$

PKZ179-211145-
Pribilof Islands Near Shore Waters-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 30 kt. Seas 10 ft. Rain.
.THU...NE wind 30 kt. Seas 10 ft. Rain.
.THU NIGHT...N wind 30 kt. Seas 10 ft.
.FRI AND FRI NIGHT...N wind 30 kt. Seas 9 ft.
.SAT...NW wind 20 kt. Seas 7 ft.
.SUN...NW wind 25 kt. Seas 7 ft.
.MON...NW wind 20 kt. Seas 6 ft.

$$

PKZ180-211145-
Kuskokwim Delta and Etolin Strait-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 25 kt. Seas 6 ft. Rain.
.THU...NE wind 25 kt except variable 10 kt S of Cape Newenham. Seas 
6 ft. Rain.
.THU NIGHT...NE wind 25 kt except S 15 kt S of Cape Newenham. Seas 6
ft.
.FRI AND FRI NIGHT...NE wind 25 kt. Seas 6 ft.
.SAT THROUGH MON...NW wind 20 kt. Seas 6 ft.

$$

PKZ181-211145-
North and West of Nunivak Island-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 25 kt. Seas 7 ft.
.THU...N wind 30 kt. Seas 8 ft.
.THU NIGHT...N wind 25 kt. Seas 8 ft.
.FRI...N wind 25 kt. Seas 8 ft.
.FRI NIGHT...N wind 30 kt. Seas 9 ft.
.SAT THROUGH SUN...N wind 25 kt. Seas 8 ft.
.MON...N wind 20 kt. Seas 8 ft.

$$

PKZ185-211145-
Saint Matthew Island Waters-
308 PM AKDT Wed Sep 20 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY NIGHT...

.TONIGHT...NE wind 30 kt. Seas 8 ft.
.THU...NE wind 30 kt. Seas 9 ft.
.THU NIGHT...N wind 25 kt. Seas 8 ft.
.FRI AND FRI NIGHT...N wind 25 kt. Seas 8 ft.
.SAT...N wind 25 kt. Seas 7 ft.
.SUN THROUGH MON...N wind 20 kt. Seas 7 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
442 AM AKDT Wed Sep 20 2017

.ANALYSIS AND UPPER LEVELS...

The polar jet remains positioned over the area in a northwest to
southeast orientation from the northern Bering across Southwest
Alaska and into the western Gulf. A wave of energy moving along
the north side of the jet is currently spreading light rain across
the Kuskokwim Delta up through the Lower Kuskokwim Valley.
Proximity to the jet appears to be hampering much southward
progress to the rainfall, however.

Another low centered south of the central Aleutians consists of a
strong warm front transporting a subtropical air mass northward
across the eastern Aleutians. The moisture-laden air mass is
producing rainfall that is heavy at times across much of the chain
this morning. This very warm air mass aloft is helping push the
jet north and east with time, which will play into the forecast
for mainland Alaska over the next few days. More on that below.

Mainly clear skies and light winds across Southcentral are
allowing temperatures to plummet across the region this morning,
with numerous locations dropping down into the 30s and threatening
a first frost for many inland locations.

&&

.MODEL DISCUSSION...

The models all are in very good agreement for much of the short-
term. One significant difference appears by Thursday evening where
the GFS depicts a much stronger secondary low developing over the
northern Gulf in advance of the subtropical air mass lifting
northward as compared with all of the other models. The other
models keep a trough over the north Gulf Coast, but it never
really develops. The result is the GFS shows much stronger winds
across the northern Gulf than the other models, and being the
outlier, was eliminated as part of the forecast. The differences
between the other models were not significant with regards to that
feature. During the day Friday, the models diverge on
precipitation coverage, with the GFS and to a lesser extent the
NAM ending the rain earlier in the day, with the other models
keeping more persistent rainfall. Forecast confidence remains
high with excellent overall model agreement, though confidence is
lower regarding those other differences between the models.

&&

.AVIATION...
PANC...VFR conditions and light winds will persist. A brief shower
or sprinkle will be possible during the day, but should not cause
any long-term changes to the VFR conditions.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A fast moving upper level short-wave trough over Southwest Alaska
this morning will cross Southcentral today, bringing a quick shot
of rain to most inland areas, including the Mat-Su and Copper
River Basin. Areas to the south will remain dry with just some
passing mid to high clouds.

All eyes will then shift to the storm south of the Aleutians,
which will send a warm front, with very warm and moist air toward
Southcentral. There will be a break tonight between the departing
short-wave and this warm front, but mid to high clouds will
stream well out ahead of it. Thus, temperatures will not fall as
far as they did this morning for most of Southcentral.

Rain will overspread Kodiak Island this evening then continue
north and east overnight through Thursday. It looks like a fairly
quick shot of steady rain for most places right out ahead of the
warm front. Development of a triple point low over the northern
Gulf on Thursday afternoon combined with progressive flow in the
upper levels will then help shunt the deepest moisture eastward
toward Southeast Alaska. A persistent supply of upper waves
transiting Southcentral combined with the fairly warm and moist
air mass in place will maintain a threat of rain Thursday night
and beyond. The forecast challenge will be to try and lock in on
specific features and associated rainfall.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
There is a fast moving low and and associated frontal boundary
moving into western Alaska. More precipitation is expected for the
Kuskokwim Delta. A break in activity is expected and then a
second wave of moisture will enter the region from the south and
move directly into the Bristol Bay coastline. Rain looks to
continue into Thursday evening and beyond as the longwave trough
extending from the Arctic phases with the upper low south of the
Aleutian chain and helps to establish broad southwest flow over
the region into the latter half of the week.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The latest ASCAT pass has the low south of Adak. The associated
warm front is overtaking the Aleutians. Expect rain and gale
force winds. These unsettled conditions will spread from the
Central and Eastern Aleutians to the Alaska Peninsula and the
Pribilof Islands as the forecast period unfolds. The eastern half
of the Bering will remain in a wet and windy pattern while
western portions of the Bering including will remain on the drier
side on the back side of the longwave trough.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Beginning the extended period forecast Thursday night, there will
be an arctic trough merging with a North Pacific warm front over
the state. Broad southwest flow will bring rain to most of
Southern Alaska heading into Saturday as the upper trough remains
in place. Uncertainty develops on Saturday night with another warm
front moving north toward the Gulf of Alaska with the ECMWF
favoring a deep 978 hpa surface low tucked into the west side of
the Gulf. However, the 12z GFS and Canadian GDPS models are
notably weaker and much farther east with the surface low.
However, even with this uncertainty, there will still be plenty of
forcing for continued coastal rain and rain chances inland through
the weekend. Eventually, the upper low will move southward into
the North Pacific and Gulf of Alaska, which, in theory, should
result in less precipitation chances heading into mid/late week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...NONE.
MARINE...Gales: 170 173 175 177 178 179 411 412 413 414
FIRE WEATHER...NONE.

&&

SYNOPSIS AND MODEL DISCUSSION...JPW
SOUTHCENTRAL ALASKA...SEB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PS
LONG TERM...JA