Small Craft Advisory 724, NWS Anchorage, AK

Issued

Sep 27, 2017, 3:13 PM AKDT (23:13 UTC)

Expired

Sep 28, 2017, 3:45 AM AKDT

In force

13 hr

Issued by

NWS Anchorage, AK

816 
FZAK52 PAFC 272313
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
313 PM AKDT Wed Sep 27 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.

PKZ199-281145-
313 PM AKDT Wed Sep 27 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

A 988 mb North Pacific 100 nm southeast of Sitkinak will move into
the western Gulf by Thu morning. High pressure over the southwest
Bering will move to the central Bering Fri.

$$

PKZ150-281145-
South of the AK Peninsula Sitkinak to Castle Cape-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...NW wind 25 kt. Seas 7 ft.
.THU...NW wind 25 kt. Seas 6 ft.
.THU NIGHT...NW wind 30 kt. Seas 7 ft.
.FRI...NW wind 25 kt. Seas 7 ft.
.FRI NIGHT...N wind 20 kt. Seas 6 ft.
.SAT THROUGH SUN...NW wind 15 kt. Seas 4 ft.
.MON...W wind 15 kt. Seas 5 ft.

$$

PKZ155-281145-
South of the AK Peninsula Castle Cape to Cape Sarichef-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...NW wind 30 kt. Seas 8 ft.
.THU...NW wind 30 kt. Seas 8 ft.
.THU NIGHT...NW wind 25 kt. Seas 7 ft.
.FRI...NW wind 25 kt. Seas 6 ft.
.FRI NIGHT...N wind 20 kt. Seas 5 ft.
.SAT...N wind 20 kt. Seas 4 ft.
.SUN...Variable wind 10 kt. Seas 3 ft.
.MON...SW wind 15 kt. Seas 7 ft.

$$

PKZ160-281145-
Bristol Bay-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...N wind 25 kt. Seas 5 ft.
.THU...NW wind 25 kt. Seas 6 ft.
.THU NIGHT...N wind 25 kt. Seas 6 ft.
.FRI AND FRI NIGHT...N wind 20 kt. Seas 5 ft.
.SAT...NW wind 20 kt. Seas 4 ft.
.SUN...W wind 10 kt. Seas 2 ft.
.MON...SW wind 10 kt. Seas 5 ft.

$$

PKZ165-281145-
Port Heiden to Cape Sarichef-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...NW wind 30 kt. Seas 9 ft.
.THU...NW wind 25 kt. Seas 9 ft.
.THU NIGHT...NW wind 25 kt. Seas 8 ft.
.FRI...N wind 25 kt. Seas 7 ft.
.FRI NIGHT...N wind 20 kt. Seas 7 ft.
.SAT...N wind 15 kt. Seas 6 ft.
.SUN...SW wind 15 kt. Seas 6 ft.
.MON...SW wind 15 kt. Seas 10 ft.

$$

PKZ170-281145-
Cape Sarichef to Nikolski Bering Side-
313 PM AKDT Wed Sep 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TONIGHT...NW wind 25 kt. Seas 8 ft.
.THU...NW wind 25 kt. Seas 8 ft.
.THU NIGHT...NW wind 15 kt. Seas 6 ft.
.FRI AND FRI NIGHT...N wind 20 kt. Seas 6 ft.
.SAT...NW wind 15 kt. Seas 5 ft.
.SUN...SW wind 20 kt. Seas 9 ft.
.MON...SW wind 15 kt. Seas 9 ft.

$$

PKZ171-281145-
Unalaska Bay-
313 PM AKDT Wed Sep 27 2017

...SMALL CRAFT ADVISORY THROUGH THURSDAY...

.TONIGHT...NW wind 25 kt. Seas 8 ft.
.THU...NW wind 25 kt. Seas 7 ft.
.THU NIGHT...NW wind 20 kt. Seas 5 ft.
.FRI AND FRI NIGHT...N wind 15 kt. Seas 5 ft.
.SAT...NW wind 10 kt. Seas 3 ft.
.SUN...SW wind 10 kt. Seas 2 ft.
.MON...SW wind 15 kt. Seas 2 ft.

$$

PKZ172-281145-
Cape Sarichef to Nikolski Pacific Side-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...NW wind 25 kt. Seas 7 ft.
.THU...NW wind 25 kt. Seas 7 ft.
.THU NIGHT...NW wind 25 kt. Seas 5 ft.
.FRI AND FRI NIGHT...N wind 20 kt. Seas 5 ft.
.SAT...N wind 20 kt. Seas 4 ft.
.SUN THROUGH MON...SW wind 15 kt. Seas 8 ft.

$$

PKZ173-281145-
Nikloski to Seguam Island Bering Side-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 20 kt. Seas 7 ft.
.THU...NW wind 20 kt. Seas 6 ft.
.THU NIGHT...NW wind 20 kt. Seas 6 ft.
.FRI...N wind 15 kt. Seas 5 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 4 ft.
.SAT...SW wind 15 kt. Seas 6 ft.
.SUN...S wind 25 kt. Seas 9 ft.
.MON...SW wind 20 kt. Seas 9 ft.

$$

PKZ174-281145-
Nikolski to Seguam Island Pacific Side-
313 PM AKDT Wed Sep 27 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...N wind 25 kt. Seas 7 ft.
.THU...NW wind 20 kt. Seas 6 ft.
.THU NIGHT...NW wind 20 kt. Seas 5 ft.
.FRI...N wind 20 kt. Seas 5 ft.
.FRI NIGHT...N wind 15 kt. Seas 4 ft.
.SAT...Variable wind 10 kt. Seas 4 ft.
.SUN...S wind 20 kt. Seas 10 ft.
.MON...SW wind 15 kt. Seas 10 ft.

$$

PKZ175-281145-
Seguam Island to Adak Bering Side-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 15 kt. Seas 6 ft.
.THU...NW wind 20 kt. Seas 5 ft.
.THU NIGHT...NW wind 20 kt. Seas 6 ft.
.FRI...NW wind 15 kt. Seas 5 ft.
.FRI NIGHT...SW wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...S wind 25 kt. Seas 8 ft.
.MON...SW wind 20 kt. Seas 8 ft.

$$

PKZ176-281145-
Seguam Island to Adak Pacific Side-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...N wind 20 kt. Seas 5 ft.
.THU...NW wind 20 kt. Seas 4 ft.
.THU NIGHT...NW wind 20 kt. Seas 4 ft.
.FRI...N wind 15 kt. Seas 4 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 3 ft.
.SAT...S wind 20 kt. Seas 7 ft.
.SUN...S wind 25 kt. Seas 12 ft.
.MON...SW wind 15 kt. Seas 10 ft.

$$

PKZ177-281145-
Adak to Kiska-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 15 kt. Seas 5 ft.
.THU...NW wind 15 kt. Seas 5 ft.
.THU NIGHT...NW wind 15 kt. Seas 4 ft.
.FRI...W wind 15 kt. Seas 3 ft.
.FRI NIGHT...S wind 30 kt. Seas 8 ft.
.SAT...S wind 35 kt. Seas 14 ft.
.SUN...SW wind 25 kt. Seas 12 ft.
.MON...SW wind 20 kt. Seas 9 ft.

$$

PKZ178-281145-
Kiska to Attu-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...W wind 15 kt. Seas 4 ft.
.THU...SW wind 15 kt. Seas 3 ft.
.THU NIGHT...SW wind 20 kt. Seas 5 ft.
.FRI AND FRI NIGHT...S wind 35 kt. Seas 15 ft.
.SAT...SW wind 35 kt. Seas 16 ft.
.SUN THROUGH MON...SW wind 25 kt. Seas 12 ft.

$$

PKZ179-281145-
Pribilof Islands Near Shore Waters-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 20 kt. Seas 6 ft.
.THU...NW wind 15 kt. Seas 5 ft.
.THU NIGHT...N wind 15 kt. Seas 4 ft.
.FRI...N wind 15 kt. Seas 4 ft.
.FRI NIGHT...Variable wind 10 kt. Seas 4 ft.
.SAT THROUGH MON...SW wind 20 kt. Seas 11 ft.

$$

PKZ180-281145-
Kuskokwim Delta and Etolin Strait-
313 PM AKDT Wed Sep 27 2017

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

.TONIGHT...N wind 30 kt. Seas 8 ft.
.THU...NW wind 25 kt. Seas 7 ft.
.THU NIGHT...N wind 25 kt. Seas 6 ft.
.FRI AND FRI NIGHT...N wind 25 kt. Seas 7 ft.
.SAT...W wind 20 kt. Seas 4 ft.
.SUN...SW wind 20 kt. Seas 6 ft.
.MON...S wind 20 kt. Seas 11 ft.

$$

PKZ181-281145-
North and West of Nunivak Island-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 20 kt. Seas 4 ft.
.THU...N wind 20 kt. Seas 4 ft.
.THU NIGHT...N wind 20 kt. Seas 6 ft.
.FRI...NW wind 20 kt. Seas 5 ft.
.FRI NIGHT...W wind 15 kt. Seas 3 ft.
.SAT THROUGH SUN...SW wind 20 kt. Seas 8 ft.
.MON...S wind 15 kt. Seas 9 ft.

$$

PKZ185-281145-
Saint Matthew Island Waters-
313 PM AKDT Wed Sep 27 2017

.TONIGHT...NW wind 15 kt. Seas 3 ft.
.THU...NW wind 15 kt. Seas 4 ft.
.THU NIGHT...N wind 15 kt. Seas 4 ft.
.FRI...SW wind 20 kt. Seas 4 ft.
.FRI NIGHT...SW wind 30 kt. Seas 9 ft.
.SAT...S wind 35 kt. Seas 17 ft.
.SUN...S wind 20 kt. Seas 13 ft.
.MON...SW wind 15 kt. Seas 10 ft.

$$

NWS Anchorage, AK wrote its last area forecast discussion before this small craft advisory went out at Sep 27, 4:35 AM AKDT, 10 hours 38 minutes earlier.

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
435 AM AKDT Wed Sep 27 2017

.ANALYSIS AND UPPER LEVELS...
An upper level low is centered just south of Dutch Harbor and is
slowly moving south while a secondary low is beginning to form to
the east over the North Pacific and rotating north towards Kodiak
Island. The upper level low is being supported by a 130 kt portion
of the sub-tropical jet stream which is taking a southward dive
into the Central Pacific. The jet then takes a sharp northward
turn into the Eastern Gulf of Alaska pumping a large influx of
warm moist sub-tropical air towards the Southeast Alaskan Coast
with precipitable water values maxing out at around 2 inches. A
front at the leading edge of this sub-tropical air is currently
moving over Southcentral with rain spreading across the Northern
Gulf Coast, Western Kenai Peninsula, and Prince William Sound.

Out West, a large area of high pressure is present over the
Western Bering Sea leading to broad northerly flow across most of
the Bering and Western Alaska as well as decreased cloud cover
over most inland locations.

&&

.MODEL DISCUSSION...
Models are all in fairly good agreement with the overall synoptic
pattern, depicting the low continuing to spin and slowly weaken
over the gulf as a high amplitude ridge builds in over the Bering
by the end of the week. There are some differences with minor
features associated with the gulf low, specifically the NAM model as
it brings the center further north which would lead to stronger
winds along the North Gulf Coast and Prince William Sound.
Continued to side with the more consistent GFS/EC solution for
this morning's forecast package.

&&

.AVIATION...
PANC...Periods of rain will move across the terminal today but
general southeast flow will tend to dry out the low levels
keeping VFR conditions throughout the day.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
The timing of rainfall, especially in Southcentral, will be one
of the forecast challenges over the next day or so. The first band
of rain that moved developed over Southcentral overnight will push
off to the west early this morning, leaving most areas with a
relatively brief break before another round of heavier rain
pushes in for the afternoon-evening hours. Rain will then likely
diminish overnight tonight as increasing cross barrier flow
develops along the Chugach Mountains as a wave moving over the
North Gulf moves inland. This will produce a persistent pressure
gradient along the North Gulf coast that will bring gusty winds
through Turnagain Arm, the Knik River Valley, and Copper River
areas through Thursday, with the strongest of these winds expected
along Turnagain Arm. There is some question as to whether these
winds will reach into the Anchorage Bowl as well with a weak down
inlet flow, however recent model runs suggest this may be more
likely for West Anchorage.

&&

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

Dry offshore flow will remain dominant across the region today
through Thursday, keeping a majority of Southwest Alaska dry and
cool as a moderated Arctic air mass moves into the region.
Sporadic light rain will impact mainly the Alaska Range today
before a better organized deformation zone forms tonight and
Thursday. This feature will spread rain over the Alaska Range and
into the foothills west of the Alaska Range.

&&

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

Broad northerly flow will dominate the entire Bering Sea as a
ridge of high pressure over the North Pacific and a low in the
Gulf of Alaska keeps the region in a stale but quiescent weather
pattern. Beyond light instability driven showers, precipitation
will remain light through the forecast period. The strongest core
of winds will be over the eastern Bering Sea where northerly winds
will gust close to 30-35 knots, enhanced a little through favored
gaps.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Day 3 (Friday) will start off with a ridge axis over Attu Island and
spanning northward into Russia, and a trough of low pressure over
much of the southern Mainland. Models are showing a pair of upper
level lows, one near Kenai and a second one south over the Gulf Of
Alaska. The low pressure system that is expected to be set up over
the western Gulf will bring continue to bring additional rainfall to
the gulf coast before dissipating Saturday morning. The surface
ridge over the Bering will get shifted eastward as the next front
tracks eastward over the Bering Friday night through Monday.

During the early half of next week, the models hinting at a
secondary shot of reinforcing energy with the next upper level
trough and associated surface low tracking through the Bering and
spreading through much of the southern Mainland by Tuesday. At this
point models are struggling with the timing and track of the systems
following the above mentioned low as they work their way across the
Bering and potentially into the southwest Mainland during the mid-to-
late week time frame. Therefore, confidence remains low in the
forecast from Monday through Wednesday next week.

&&

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

&&

SYNOPSIS AND MODEL DISCUSSION...KVP
SOUTHCENTRAL ALASKA...DEK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JA
LONG TERM...PS/TP

Small Craft Advisories in Alaska, 2017Every small craft advisory in 2017

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text.