Small Craft Advisory 803, NWS Anchorage, AK

167 
FZAK52 PAFC 232332
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
332 PM AKDT Mon Oct 23 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.

PKZ199-241230-
332 PM AKDT Mon Oct 23 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 1003 mb low 390 nm southeast of Sand Point will move into the 
western Gulf by Tue morning. A 953 mb low 340 nm west of Shemya 
will move to 75 nm southwest of Shemya at 935 mb by Tue 
afternoon. Then it will move to 75 nm west of Dutch Harbor at 965 
mb by Wed afternoon.

$$

PKZ150-241230-
South of the AK Peninsula Sitkinak to Castle Cape-
332 PM AKDT Mon Oct 23 2017

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...Variable wind 10 kt becoming NE 20 kt after midnight.
Seas 4 ft.
.TUE...NW wind 15 kt becoming SW 30 kt in the afternoon. Seas 9
ft.
.TUE NIGHT...S wind 45 kt. Seas 23 ft. Rain.
.WED...S wind 40 kt. Seas 25 ft.
.WED NIGHT...S wind 25 kt. Seas 20 ft.
.THU...SW wind 25 kt. Seas 16 ft.
.FRI...SW wind 20 kt. Seas 14 ft.
.SAT...S wind 15 kt. Seas 7 ft.

$$

PKZ155-241230-
South of the AK Peninsula Castle Cape to Cape Sarichef-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...SW wind 15 kt. Seas 4 ft.
.TUE...S wind 25 kt increasing to 50 kt in the afternoon, Seas 8 ft 
building to 21 ft in the afternoon. From the Shumagin Islands E, SW 
wind 15 kt becoming S 40 kt in the afternoon, Seas 5 ft building to 
12 ft in the afternoon. Rain.
.TUE NIGHT...S wind 50 kt becoming SW 30 kt after midnight. From the
Shumagin Islands E, S wind 45 kt. Seas 24 ft.
.WED...S wind 30 kt. Seas 21 ft.
.WED NIGHT...S wind 35 kt. Seas 24 ft.
.THU...SW wind 30 kt. Seas 23 ft.
.FRI...SW wind 25 kt. Seas 14 ft.
.SAT...S wind 15 kt. Seas 16 ft.

$$

PKZ160-241230-
Bristol Bay-
332 PM AKDT Mon Oct 23 2017

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...S wind 20 kt. Seas 5 ft. Snow showers.
.TUE...S wind 15 kt becoming SE 30 kt in the afternoon. Seas 5 ft.
.TUE NIGHT...SE wind 45 kt. Seas 10 ft. Rain.
.WED...S wind 20 kt. Seas 7 ft.
.WED NIGHT...SE wind 25 kt. Seas 6 ft.
.THU THROUGH FRI...S wind 25 kt. Seas 9 ft.
.SAT...S wind 20 kt. Seas 5 ft.

$$

PKZ165-241230-
Port Heiden to Cape Sarichef-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY...

.TONIGHT...S wind 20 kt. Seas 5 ft. Snow showers.
.TUE...S wind 35 kt becoming SE 50 kt in the afternoon. Gusts to 65
kt out of bays and passes. From Port Moller E, S wind 20 kt becoming
SE 40 kt in the afternoon. Seas 6 ft building to 14 ft in the 
afternoon. Rain.
.TUE NIGHT...S wind 45 kt diminishing to 30 kt after midnight.
Seas 14 ft.
.WED AND WED NIGHT...SE wind 30 kt. Seas 12 ft.
.THU THROUGH FRI...SW wind 25 kt. Seas 11 ft.
.SAT...S wind 15 kt. Seas 6 ft.

$$

PKZ170-241230-
Cape Sarichef to Nikolski Bering Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY...

.TONIGHT...SW wind 15 kt becoming S 30 kt after midnight. Seas 7
ft. Rain.
.TUE...S wind 50 kt with gusts up to 65 kt out of bays and passes. 
Seas 18 ft. Rain.
.TUE NIGHT...SW wind 30 kt. Seas 15 ft.
.WED...SE wind 35 kt. Seas 17 ft.
.WED NIGHT...S wind 30 kt. Seas 15 ft.
.THU...W wind 30 kt. Seas 12 ft.
.FRI...SW wind 25 kt. Seas 11 ft.
.SAT...S wind 15 kt. Seas 10 ft.

$$

PKZ171-241230-
Unalaska Bay-
332 PM AKDT Mon Oct 23 2017

...GALE WARNING TUESDAY...

.TONIGHT...Variable wind less than 10 kt becoming S 20 kt after
midnight. Seas 3 ft. Rain.
.TUE...SE wind 45 kt with gusts up to 65 kt. Seas 7 ft. Rain.
.TUE NIGHT...SW wind 20 kt. Seas 3 ft.
.WED...SE wind 30 kt. Seas 5 ft.
.WED NIGHT...S wind 25 kt. Seas 4 ft.
.THU...W wind 25 kt. Seas 4 ft.
.FRI...SW wind 20 kt. Seas 3 ft.
.SAT...S wind 10 kt. Seas 2 ft.

$$

PKZ172-241230-
Cape Sarichef to Nikolski Pacific Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY...

.TONIGHT...Variable wind 10 kt becoming S 30 kt after midnight.
Seas 6 ft.
.TUE...S wind 55 kt. Seas 19 ft building to 25 ft in the
afternoon. Rain.
.TUE NIGHT...SW wind 30 kt. Seas 24 ft.
.WED AND WED NIGHT...SW wind 40 kt. Seas 31 ft.
.THU...W wind 30 kt. Seas 23 ft.
.FRI...SW wind 25 kt. Seas 13 ft.
.SAT...S wind 15 kt. Seas 17 ft.

$$

PKZ173-241230-
Nikloski to Seguam Island Bering Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY...

.TONIGHT...S wind 25 kt becoming SE 50 kt after midnight. Seas 7
ft building to 15 ft after midnight. Rain.
.TUE...S wind 55 kt becoming SW 35 kt in the afternoon. Seas 23
ft. Rain.
.TUE NIGHT...S wind 35 kt. Seas 19 ft. Widespread rain showers.
.WED...S wind 40 kt. Seas 21 ft.
.WED NIGHT...NW wind 35 kt. Seas 15 ft.
.THU...W wind 30 kt. Seas 14 ft.
.FRI...SW wind 25 kt. Seas 12 ft.
.SAT...S wind 15 kt. Seas 10 ft.

$$

PKZ174-241230-
Nikolski to Seguam Island Pacific Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY...

.TONIGHT...S wind 25 kt increasing to 50 kt after midnight. Seas
7 ft building to 15 ft after midnight. Rain.
.TUE...S wind 55 kt becoming SW 40 kt in the afternoon. Seas 26
ft. Rain.
.TUE NIGHT...SW wind 35 kt becoming S 45 kt after midnight. Seas
31 ft. Rain.
.WED...S wind 45 kt. Seas 39 ft.
.WED NIGHT...W wind 35 kt. Seas 31 ft.
.THU...W wind 30 kt. Seas 21 ft.
.FRI...SW wind 25 kt. Seas 15 ft.
.SAT...S wind 15 kt. Seas 12 ft.

$$

PKZ175-241230-
Seguam Island to Adak Bering Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY...

.TONIGHT...SE wind 45 kt increasing to 55 kt after midnight. Seas
11 ft building to 20 ft after midnight. Rain.
.TUE...SW wind 55 kt diminishing to 40 kt in the afternoon. Seas
20 ft. Rain.
.TUE NIGHT...SE wind 40 kt. Seas 20 ft. Rain showers.
.WED AND WED NIGHT...NW wind 35 kt. Seas 16 ft.
.THU...W wind 30 kt. Seas 13 ft.
.FRI...SW wind 25 kt. Seas 11 ft.
.SAT...Variable wind 10 kt. Seas 8 ft.

$$

PKZ176-241230-
Seguam Island to Adak Pacific Side-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...S wind 45 kt increasing to 55 kt after midnight. Seas
12 ft building to 24 ft after midnight. Rain.
.TUE...SW wind 55 kt diminishing to 40 kt in the afternoon. Seas
32 ft. Rain.
.TUE NIGHT...SW wind 35 kt increasing to 50 kt after midnight. Seas 
35 ft building to 42 ft after midnight. Widespread rain showers.
.WED...W wind 40 kt. Seas 41 ft.
.WED NIGHT...NW wind 35 kt. Seas 28 ft.
.THU...W wind 30 kt. Seas 19 ft.
.FRI...SW wind 30 kt. Seas 13 ft.
.SAT...S wind 15 kt. Seas 8 ft.

$$

PKZ177-241230-
Adak to Kiska-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...SE wind 55 kt. Seas 24 ft. Rain.
.TUE...SW wind 50 kt. Seas 27 ft bering side... 42 ft Pacific side. 
Widespread rain showers.
.TUE NIGHT...S wind 50 kt becoming N 40 kt after midnight. Seas
27 ft bering side...46 ft Pacific side.
.WED...NW wind 45 kt. Seas 33 ft.
.WED NIGHT...NW wind 35 kt. Seas 23 ft.
.THU THROUGH FRI...W wind 25 kt. Seas 14 ft.
.SAT...N wind 15 kt. Seas 9 ft.

$$

PKZ178-241230-
Kiska to Attu-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING THROUGH TUESDAY NIGHT...

.TONIGHT...S wind 55 kt. Bering side, seas 25 ft. Pacific side, seas
23 ft building to 30 ft after midnight. Rain.
.TUE...SW wind 50 kt. Seas 32 ft bering side... 46 ft Pacific side. 
Rain.
.TUE NIGHT...N wind 35 kt increasing to 50 kt after midnight. Bering
side, seas 35 ft. Pacific side, seas 44 ft subsiding to 35 ft after 
midnight.
.WED...NW wind 40 kt. Seas 29 ft.
.WED NIGHT...W wind 30 kt. Seas 22 ft.
.THU...SW wind 25 kt. Seas 15 ft.
.FRI THROUGH SAT...N wind 20 kt. Seas 11 ft.

$$

PKZ179-241230-
Pribilof Islands Near Shore Waters-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY...

.TONIGHT...Variable wind 10 kt becoming SE 25 kt after midnight.
Seas 6 ft.
.TUE...SE wind 35 kt increasing to 50 kt in the afternoon. Seas 12 
ft building to 20 ft in the afternoon. Rain and snow.
.TUE NIGHT...S wind 25 kt. Seas 18 ft.
.WED...SE wind 25 kt. Seas 17 ft.
.WED NIGHT...NE wind 20 kt. Seas 16 ft.
.THU...W wind 25 kt. Seas 10 ft.
.FRI...SW wind 25 kt. Seas 10 ft.
.SAT...S wind 15 kt. Seas 9 ft.

$$

PKZ180-241230-
Kuskokwim Delta and Etolin Strait-
332 PM AKDT Mon Oct 23 2017

...GALE WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...SW wind 20 kt. Seas 5 ft. Snow showers.
.TUE...S wind 20 kt becoming SE 40 kt in the afternoon. Seas 5 ft
building to 10 ft in the afternoon. Rain.
.TUE NIGHT...SE wind 45 kt becoming S 30 kt after midnight. Seas
15 ft. Rain.
.WED...S wind 25 kt. Seas 11 ft.
.WED NIGHT...SE wind 30 kt. Seas 10 ft.
.THU THROUGH FRI...SW wind 25 kt. Seas 10 ft.
.SAT...S wind 20 kt. Seas 8 ft.

$$

PKZ181-241230-
North and West of Nunivak Island-
332 PM AKDT Mon Oct 23 2017

...GALE WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...Variable wind 10 kt. Seas 4 ft.
.TUE...E wind 20 kt increasing to 35 kt in the afternoon. Seas 3
ft building to 7 ft in the afternoon. Rain.
.TUE NIGHT...E wind 45 kt. Seas 14 ft. Widespread rain showers and
snow.
.WED...S wind 25 kt. Seas 11 ft.
.WED NIGHT...SE wind 20 kt. Seas 10 ft.
.THU...SE wind 20 kt. Seas 7 ft.
.FRI THROUGH SAT...SW wind 20 kt. Seas 8 ft.

$$

PKZ185-241230-
Saint Matthew Island Waters-
332 PM AKDT Mon Oct 23 2017

...STORM WARNING TUESDAY AND TUESDAY NIGHT...

.TONIGHT...E of Saint Matthew Island, E wind 15 kt. W of Saint
Matthew Island, E wind 25 kt increasing to 40 kt after midnight.
Seas 7 ft.
.TUE...E of Saint Matthew Island, E wind 30 kt increasing to 45 kt
in the afternoon. W of Saint Matthew Island, E wind 50 kt. Seas
15 ft building to 22 ft in the afternoon. Rain.
.TUE NIGHT...E wind 45 kt E of Saint Matthew Island... NE 55 kt W
of Saint Matthew Island. Seas 26 ft. Widespread rain showers.
.WED...NE wind 45 kt. Seas 26 ft.
.WED NIGHT...NE wind 30 kt. Seas 18 ft.
.THU...N wind 25 kt. Seas 13 ft.
.FRI...NW wind 20 kt. Seas 13 ft.
.SAT...W wind 15 kt. Seas 10 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
421 PM AKDT Sun Oct 22 2017

.ANALYSIS AND UPPER LEVELS...
A deep upper level trough has carved itself out over the Bering
Sea and into the North Pacific, reaching as far south as 35N. The
center of the upper level arctic low is centered over the Y-K
Delta with a broad area of cold air advection over the Bering
Sea. Closer to Alaska, there is a trio of low amplitude shortwave
troughs embedded within the cold air. The first is a very subtle
feature lifting northeast across Cook Inlet this afternoon. This
one, however, is weak and rather moisture starved. A more
substantial shortwave is developing south of the Alaska Peninsula,
and there is another on satellite imagery developing south of
that feature around 43N. Rounding out the synoptic features...there
is an upper level low just west of the Kamchatka Peninsula, and
this will eventually merge with the remnants of Typhoon Lan and
deepen into a strong storm over the Bering Sea.

In terms of impacts for the mainland, the biggest story remains
convectively enhanced snow showers, which have been focused over
the Bering Sea and Southwest coast, some of which have been quite
heavy along the AKPen. However, a batch of instability driven
showers are also showing up on both the Kenai and Middleton radar
sites, likely enhanced by the subtle shortwave trough lifting
through Cook Inlet.

&&

.MODEL DISCUSSION...
The numerical weather models remain consistent in depicting the
general synoptic pattern through late week, but are in overall
terrible agreement and consistency regarding smaller scale details
associated with the pattern. These details revolve around shortwave
trough features embedded within the larger scale upper level
trough. It seems most of the low level forcing with these subtle
lows is associated with instability/convective driven ascent given
the very steep low level lapse rates. Moreover, the complex wave
mergers as these lows move north toward Southcentral further muddy
the details. For this forecast, a blend of the NAM and ECMWF were
favored for snow potential across Southcentral. The GFS was an
outlier with a much deeper, slower, and farther west track with
the second low moving towards Southcentral Tuesday.

Out across the Bering Sea, the models are in excellent agreement
with the developing near hurricane force low over the western
Bering Sea, so a blend of all the models was favored.

&&

.AVIATION...
PANC...VFR conditions will dominate through the TAF period with
just some passing mid level clouds in the vicinity. Winds are
expected to remain less than 10 kts.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The longwave pattern featuring a sprawling Arctic low over
western Alaska with southwesterly flow into Southcentral will
remain in place through Tuesday morning. Upper-level disturbances
will continue to rotate around the wave and up Cook Inlet, which
will keep chances for snow in the forecast. Models are notoriously
bad at handling individual waves in this pattern, so timing of
snowfall continues to be a forecast challenge. With the exception
of a few light flurries scattered over the area, the next shot of
organized precipitation looks to affect the Anchorage/Kenai area
Monday afternoon/evening. The wave responsible for this low is
currently south of the Alaska Peninsula. As this feature moves to
near Kodiak Island this evening, rain/snow will spread over the
lower Cook Inlet area and Kodiak Island. By Monday morning,
precipitation will move to the southern Kenai Peninsula with
mainly snow falling over land and some mixed precipitation over
the waters. Monday evening, the wave will move into Southcentral,
spreading light snow over the area. Lower-level support is weak
at this time, so expect snow accumulations to be fairly minimal.
Between one and two inches are possible along the Anchorage
Hillside and higher elevations, while under an inch, if anything,
is expected in the Anchorage Bowl.

The snow should taper off Monday night before the next low quickly
moves into the area Tuesday morning. The dynamics associated with
this system are much more impressive than Monday's weak low, so
expect Tuesday's to be a much more impactful system. Models are
having difficulty coming to a consensus on the track of the low as
it tracks to the northern Gulf Tuesday afternoon, so confidence
in the exact timing and placement of Tuesday's snow is fairly low.
However, confidence is rising that this system will bring
snowfall that will impact portions of the Kenai Peninsula,
Anchorage, and Mat-Su Valleys on Tuesday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 through 3)...
A North Pacific low developing south of the Alaska Peninsula will
track north tonight spreading snow across the eastern areas of
Bristol Bay. The track of this system is expected to track north
across the Aleutian Range through Monday afternoon as it weakens
into a trough. A winter weather advisory was issued during the
afternoon package for areas east of King Salmon as heavy snow is
expected to accumulate along the Aleutian Range. The next front to
move into the southwest reaches the coast Tuesday. Southeasterly
gusty winds increase along the coast Tuesday afternoon as the
frontal boundary moves across the eastern Bering. Precipitation
will likely start as snow then quickly change over to rain as a
warm air mass advects inland, however the Kuskokwim Valley should
be monitored for changes as the cold pool along the Western Alaska
Range may bring precipitation challenges late Wednesday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 through 3)...
A strong extra-tropical low (being fed by warmth and moisture from
Typhoon LAN) tracks northward tonight, pushing a frontal system
across the western Aleutians. Heavy rain and gusty southeasterly
winds develop overnight across Shemya along the boundary. The high
wind watches for the western and central Aleutians were upgraded
to warnings during the afternoon package as confidence increased
for gusts between 70 to 80 mph to occur along the boundary Monday
through Monday night. Storm force winds with hurricane force
gusts are expected across the marine waters surrounding the
western and central Aleutian islands along with seas between 40
to 50 ft. The low center picks up eastward momentum by Tuesday
morning and pushes the frontal boundary into the eastern and
northern Bering. As it tracks to the east the low slowly fills,
however this system remains strong enough on its track to bring
max gale and storm force winds to the rest of the Bering through
Wednesday. Moderate to heavy rain will accompany this system,
reducing visibility at times.

&&

.LONG TERM FORECAST (Days 3 through 7)...
An active pattern is expected to continue during the long range
forecast through the end of next week. The focus remains on an
upper level disturbance tracking over the northern Gulf and
Southcentral Alaska Tuesday evening into Wednesday, as well as
the very deep low with tropical connections tracking across the
Bering and Southern Mainland through the end of next week.

An upper level wave tracking further inland over Southcentral
Tuesday night, along with a surface low over the northwestern
Gulf, can bring another shot of snow for the southcentral area
through Wednesday. Highest snowfall totals are currently expected
along the Eastern Kenai and areas surrounding Prince William sound
Tuesday afternoon though Wednesday morning. Models are still
struggling with the overall timing and track of the low, but have
started to show a trend toward tracking it over the western
Gulf/eastern Kenai. Confidence is still not high in this scenario,
but if models continue to trend in this direction it will increase
the potential for the above mentioned snowfall to occur.

The leading frontal system ahead of the rapidly deepening low over
the NW Pacific will track eastward through the eastern Aleutians,
Alaska Peninsula, and Southwest Mainland Tuesday into Wednesday.
This will begin to usher in warmer temperatures over the eastern
Bering and southwest mainland by Wednesday morning, and build over
much of the southern Mainland through the end of the week. This
system will also bring some moderate to heavy precipitation to
these areas, as well as strong gusty winds. Rain is expected to be
the dominant precipitation type along the Aleutians and Alaska
Peninsula given the warming southerly flow and heavy marine
influence. The southern Mainland on the other hand will start off
as snow Tuesday afternoon and transition to rain or a rain snow
mix along the Gulf and Southwest coast Thursday. Models remain in
good agreement through the later half of the week regarding this
system, but confidence begins to wane as the models begin
struggling more with the track and timing as the low center tracks
into the eastern Bering on Thursday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...High Wind Warning 187 191. Winter Weather Advisory 161.
MARINE...Storm Warning 173 174 175 176 177 178.
 		 Gale Warning 185.

&&

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