Small Craft Advisory 771, NWS Anchorage, AK

324 
FZAK52 PAFC 122336
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
336 PM AKDT Thu Oct 12 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.

PKZ199-131245-
336 PM AKDT Thu Oct 12 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 963 mb low 270 nm southwest of Gambell moves to 350 nm northwest
of Gambell at 977 mb Fri afternoon. A 998 mb low 80 nm southeast 
of Adak Fri morning moves to 75 nm southeast of Sitkinak at 990 mb Sat
afternoon.

$$

PKZ150-131245-
South of the AK Peninsula Sitkinak to Castle Cape-
336 PM AKDT Thu Oct 12 2017

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

.TONIGHT...W wind 25 kt. Seas 13 ft.
.FRI...W wind 20 kt. Seas 10 ft.
.FRI NIGHT...S wind 20 kt increasing to 30 kt after midnight. Seas
9 ft.
.SAT...SW wind 40 kt. Seas 20 ft.
.SAT NIGHT...NW wind 30 kt. Seas 14 ft.
.SUN...W wind 30 kt. Seas 13 ft.
.MON THROUGH TUE...NW wind 20 kt. Seas 9 ft.

$$

PKZ155-131245-
South of the AK Peninsula Castle Cape to Cape Sarichef-
336 PM AKDT Thu Oct 12 2017

...STORM WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 12 ft.
.FRI...SW wind 25 kt. Seas 10 ft.
.FRI NIGHT...S wind 40 kt becoming SW 50 kt after midnight, Seas
14 ft building to 21 ft after midnight. From the Shumagin Islands
E, S wind 25 kt becoming 35 kt after midnight, Seas 13 ft. Rain.
.SAT...W wind 50 kt. Seas 21 ft.
.SAT NIGHT...W wind 30 kt. Seas 13 ft.
.SUN THROUGH MON...W wind 25 kt. Seas 10 ft.
.TUE...NW wind 25 kt. Seas 17 ft.

$$

PKZ160-131245-
Bristol Bay-
336 PM AKDT Thu Oct 12 2017

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

.TONIGHT...SW wind 25 kt. Seas 8 ft.
.FRI...SW wind 25 kt. Seas 9 ft.
.FRI NIGHT...SE wind 25 kt. Seas 7 ft.
.SAT...NE wind 25 kt. Seas 6 ft.
.SAT NIGHT...NW wind 25 kt. Seas 6 ft.
.SUN...W wind 25 kt. Seas 7 ft.
.MON...W wind 20 kt. Seas 6 ft.
.TUE...NW wind 15 kt. Seas 4 ft.

$$

PKZ165-131245-
Port Heiden to Cape Sarichef-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 17 ft.
.FRI...S wind 30 kt except SW 20 kt from Port Moller E. Seas 15
ft.
.FRI NIGHT...S wind 40 kt except SE 30 kt from Port Moller E. Seas 
13 ft. Rain.
.SAT...NW wind 35 kt. Seas 11 ft.
.SAT NIGHT...W wind 25 kt. Seas 9 ft.
.SUN...W wind 25 kt. Seas 9 ft.
.MON...W wind 20 kt. Seas 9 ft.
.TUE...NW wind 20 kt. Seas 9 ft.

$$

PKZ170-131245-
Cape Sarichef to Nikolski Bering Side-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 21 ft.
.FRI...S wind 25 kt increasing to 35 kt in the afternoon. Seas
18 ft.
.FRI NIGHT...SW wind 45 kt becoming NW after midnight. Seas 15 ft. 
Rain.
.SAT...W wind 30 kt. Seas 13 ft.
.SAT NIGHT...W wind 25 kt. Seas 10 ft.
.SUN THROUGH MON...SW wind 25 kt. Seas 10 ft.
.TUE...NW wind 25 kt. Seas 18 ft.

$$

PKZ171-131245-
Unalaska Bay-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 3 ft.
.FRI...S wind 15 kt increasing to 25 kt in the afternoon. Seas 2
ft building to 4 ft in the afternoon. Rain.
.FRI NIGHT...W wind 45 kt. Seas 7 ft. Rain.
.SAT...W wind 30 kt. Seas 5 ft.
.SAT NIGHT...W wind 15 kt. Seas 2 ft.
.SUN...W wind 20 kt. Seas 2 ft.
.MON...SW wind 15 kt. Seas 2 ft.
.TUE...W wind 20 kt. Seas 2 ft.

$$

PKZ172-131245-
Cape Sarichef to Nikolski Pacific Side-
336 PM AKDT Thu Oct 12 2017

...STORM WARNING FRIDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 13 ft.
.FRI...SW wind 25 kt becoming S 40 kt in the afternoon. Seas 14
ft.
.FRI NIGHT...W wind 50 kt. Seas 20 ft. Rain.
.SAT...W wind 35 kt. Seas 15 ft.
.SAT NIGHT...W wind 25 kt. Seas 9 ft.
.SUN THROUGH MON...SW wind 25 kt. Seas 11 ft.
.TUE...W wind 25 kt. Seas 19 ft.

$$

PKZ173-131245-
Nikloski to Seguam Island Bering Side-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 22 ft.
.FRI...S wind 30 kt increasing to 40 kt in the afternoon. Seas
18 ft. Rain.
.FRI NIGHT...W wind 45 kt diminishing to 30 kt after midnight.
Seas 16 ft.
.SAT AND SAT NIGHT...W wind 25 kt. Seas 11 ft.
.SUN...W wind 25 kt. Seas 11 ft.
.MON...SW wind 20 kt. Seas 15 ft.
.TUE...W wind 20 kt. Seas 20 ft.

$$

PKZ174-131245-
Nikolski to Seguam Island Pacific Side-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 25 kt. Seas 17 ft.
.FRI...S wind 30 kt increasing to 45 kt in the afternoon. Seas
19 ft. Widespread rain showers.
.FRI NIGHT...W wind 45 kt diminishing to 30 kt after midnight.
Seas 19 ft.
.SAT...W wind 25 kt. Seas 12 ft.
.SAT NIGHT...W wind 20 kt. Seas 9 ft.
.SUN...W wind 25 kt. Seas 10 ft.
.MON...SW wind 20 kt. Seas 18 ft.
.TUE...W wind 25 kt. Seas 21 ft.

$$

PKZ175-131245-
Seguam Island to Adak Bering Side-
336 PM AKDT Thu Oct 12 2017

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

.TONIGHT...SW wind 30 kt. Seas 21 ft.
.FRI...S wind 25 kt becoming W in the afternoon. Seas 16 ft. Rain.
.FRI NIGHT...W wind 30 kt. Seas 12 ft.
.SAT...W wind 30 kt. Seas 12 ft.
.SAT NIGHT...W wind 25 kt. Seas 11 ft.
.SUN...W wind 25 kt. Seas 10 ft.
.MON...SW wind 20 kt. Seas 22 ft.
.TUE...W wind 20 kt. Seas 22 ft.

$$

PKZ176-131245-
Seguam Island to Adak Pacific Side-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING FRIDAY...

.TONIGHT...SW wind 25 kt. Seas 16 ft.
.FRI...S wind 30 kt becoming SW wind 40 kt in the late morning. Seas
15 ft. Rain.
.FRI NIGHT...W wind 30 kt. Seas 14 ft.
.SAT...W wind 25 kt. Seas 10 ft.
.SAT NIGHT...W wind 20 kt. Seas 8 ft.
.SUN...W wind 25 kt. Seas 10 ft.
.MON...SW wind 30 kt. Seas 20 ft.
.TUE...W wind 25 kt. Seas 20 ft.

$$

PKZ177-131245-
Adak to Kiska-
336 PM AKDT Thu Oct 12 2017

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

.TONIGHT...SW wind 30 kt. Seas 20 ft.
.FRI...W wind 25 kt. Seas 13 ft.
.FRI NIGHT...W wind 30 kt. Seas 11 ft.
.SAT...W wind 30 kt. Seas 12 ft.
.SAT NIGHT...W wind 25 kt. Seas 11 ft.
.SUN...W wind 25 kt. Seas 10 ft.
.MON...W wind 30 kt. Seas 19 ft.
.TUE...W wind 25 kt. Seas 19 ft.

$$

PKZ178-131245-
Kiska to Attu-
336 PM AKDT Thu Oct 12 2017

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

.TONIGHT...SW wind 30 kt. Seas 19 ft.
.FRI...Variable wind 15 kt becoming W wind 30 kt in the late 
morning. Seas 13 ft.
.FRI NIGHT...W wind 30 kt. Seas 12 ft.
.SAT...W wind 30 kt. Seas 12 ft.
.SAT NIGHT...W wind 25 kt. Seas 12 ft.
.SUN...SW wind 25 kt. Seas 11 ft.
.MON...W wind 30 kt. Seas 17 ft.
.TUE...W wind 25 kt. Seas 14 ft.

$$

PKZ179-131245-
Pribilof Islands Near Shore Waters-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING TONIGHT...

.TONIGHT...SW wind 35 kt. Seas 24 ft.
.FRI...SW wind 25 kt. Seas 19 ft.
.FRI NIGHT...Variable wind 10 kt becoming NW 20 kt after midnight. 
Seas 12 ft.
.SAT AND SAT NIGHT...W wind 25 kt. Seas 11 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 10 ft.
.TUE...NW wind 15 kt. Seas 12 ft.

$$

PKZ180-131245-
Kuskokwim Delta and Etolin Strait-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING TONIGHT...

.TONIGHT...SW wind 35 kt. Seas 15 ft.
.FRI...SW wind 30 kt. Seas 14 ft.
.FRI NIGHT...S wind 25 kt. Seas 10 ft.
.SAT AND SAT NIGHT...W wind 20 kt. Seas 8 ft.
.SUN THROUGH MON...W wind 20 kt. Seas 8 ft.
.TUE...NW wind 15 kt. Seas 5 ft.

$$

PKZ181-131245-
North and West of Nunivak Island-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING TONIGHT...

.TONIGHT...S wind 40 kt. Seas 20 ft.
.FRI...SW wind 30 kt. Seas 16 ft.
.FRI NIGHT...S wind 20 kt. Seas 11 ft.
.SAT AND SAT NIGHT...W wind 15 kt. Seas 8 ft.
.SUN THROUGH MON...NW wind 20 kt. Seas 7 ft.
.TUE...N wind 15 kt. Seas 6 ft.

$$

PKZ185-131245-
Saint Matthew Island Waters-
336 PM AKDT Thu Oct 12 2017

...GALE WARNING THROUGH FRIDAY...

.TONIGHT...SW wind 40 kt. Seas 27 ft.
.FRI...SW wind 35 kt. Seas 22 ft.
.FRI NIGHT...S wind 20 kt E of Saint Matthew Island... SW 25 kt W
of Saint Matthew Island. Seas 16 ft.
.SAT...SW wind 25 kt. Seas 12 ft.
.SAT NIGHT...SW wind 20 kt. Seas 10 ft.
.SUN...W wind 20 kt. Seas 10 ft.
.MON...NW wind 15 kt. Seas 7 ft.
.TUE...N wind 20 kt. Seas 9 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
420 PM AKDT Wed Oct 11 2017

.ANALYSIS AND UPPER LEVELS...
An amplifying upper level ridge is tracking across the mainland
part of the state today as it is being pushed eastward by a strong
upper level low in the northwest Bering Sea. The jet stream is
wrapping around the low to the south and then moves over the north
side of the ridge. This is bringing strong southerly flow over the
central Bering Sea.
At the surface the low is in the northwest Bering Sea and around
958 mb this afternoon. This large low encompasses the entire
Bering Sea and into Southwest Alaska.

&&

.MODEL DISCUSSION...
Models are in good agreement with the significant exception of a
low tracking rapidly near the Aleutians and into Bristol Bay or
the AK Peninsula Friday into Saturday. This is a pattern where
models typically struggle. The GFS is by far the most northerly
brining it onshore near Dillingham. The ECMWF is holding firm
with a solution taking it south of the Alaska Peninsula. The
Canadian and NAM are in between but differ in speed. All solutions
are significantly farther south than yesterday. Afternoon
forecasts reflect a track through the center of Bristol Bay,
which looks likely at this point. This track will minimize the
chance of any coastal flooding with the weekend low.

&&

.AVIATION...
PANC...VFR conditions and light winds will remain for the rest of
the night. Rain should move into the area tomorrow but conditions
will likely remain mostly VFR as southeasterly flow helps keep
ceilings in the 3500 to 5000 ft range.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
An amplifying ridge building in over the Mainland this evening
will maintain westerly flow across the Gulf, along with some weak
gap winds along the north Gulf coast. Mostly drier and cloudy
conditions are expected through Thursday morning, with a few
lingering showers over the Susitna Valley and Copper River Basin.
The focus will then shift to a large storm system tracking over
the far western Bering Sea, and the associated front marching
eastward into the western Gulf by Thursday morning. As is so often
the case, expect development of a triple point low over the far
western Gulf as the frontal system makes its way through the
western Gulf. This will lead to strengthening low level
southeasterly winds ahead of the low on Thursday, from the
northern Gulf across Prince William Sound to the Kenai Peninsula,
Turnagain Arm and Anchorage. However, instead of downslope drying,
deep and moist southwest flow aloft combined with a series of
sharp upper level short-waves will lead to steady rainfall for the
population centers Thursday through Friday morning. Strong gusty
gap winds are also expected to develop along Turnagain arm
Thursday, and diminish Friday morning.

Marginally colder air will filter into Southcentral overnight
Thursday into Friday, leading to falling snow levels area-wide.
Upslope flow along the west side of the Chugach and Talkeetna
Mountains combined with potential for locally heavy precipitation
as a short-wave moves through the region could lower snow levels
even more. For now, we have kept the potential for snowfall over
the Copper River Basin, and along the higher elevations of the
Chugach and Talkeetna mountains.

&&

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

The southwest coast of Alaska is experiencing gusty south to
southeasterly winds this afternoon as a front approaches the
shore. Expect winds to taper off overnight as the front moves
onshore and weakens. Rain associated with the front has already
reached the lower Kuskokwim Delta and Bristol Bay area. As the
front pushes east tonight, expect rain to continue through
Thursday, tapering off from west to east Thursday afternoon.
Behind the front, continued strong southwesterly flow over the
Bering Sea will raise water levels along coastal areas of the
Kuskokwim Delta Thursday. Minor flooding of coastal low lying
areas is possible during high tide Thursday afternoon. Once the
front has pushed through the area, temperatures will cool
throughout the day Thursday. Friday will be cooler and showery
with temperatures returning to near normal for this time of year
after a few relatively warm (albeit wet) days.

&&

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

The low pressure system over the western Bering Sea will reach
peak intensity overnight before beginning to gradually weaken
Thursday morning. A swath of storm force winds over the western
Aleutians and western Bering will weaken to gale force as the
system moves north Thursday afternoon. By late Thursday night,
this low will move into eastern Siberia, leaving much of the
Bering Sea in a broad cyclonic, showery pattern overnight.
The next system to impact the area will approach the western and
central Aleutians from the southwest Friday morning. A strong
zonal jet to the south of the western Aleutians will move the
feature quickly east, however models are struggling with the exact
track and intensity of the low. Current thinking is that the low
will move along the base of the longwave trough, tracking eastward
just to the north of the Alaska Peninsula Friday through Friday
evening, then crossing into the western Gulf by Saturday morning.
The main impacts of this low will be felt along the Aleutians,
with a small swath of storm force winds possible around the
central and eastern Aleutians Friday night. With the difficulties
in the handling of this system, forecast confidence in the exact
placement of the strongest core of winds is fairly low.

&&

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

Saturday, the models have a low near the AKPEN. There have been
some major model discrepancies with the track of the low. The
ECMWF has brought the surface low south of the AKPEN while the GFS
has kept it well north of the AKPEN. The NAM is trending slightly
more to the south. There is still a lot of uncertainty with this
storm and it will impact everything from potential storm surge
issues to rainfall amounts. Given the vagaries of the models,
expect more updates associated with this system. Next week, the
pattern stays very active across the Bering Sea. As the zonal jet
continues, expect new systems to be steered across the AKPEN and
into the Gulf. This would result in calmer and clearer weather
across the mainland. The models are picking up on colder air
pooling up over the interior and spilling over the Alaska Range.
Increasing confidence that there will be a cold air outbreak by
the middle of next week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 191
MARINE...None.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...TP
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...RD
LONG TERM...PS