Small Craft Advisory 855, NWS Anchorage, AK

Issued

Nov 9, 2017, 2:48 AM AKST (11:48 UTC)

Expired

Nov 9, 2017, 3:45 PM AKST

In force

13 hr

Issued by

NWS Anchorage, AK

532 
FZAK52 PAFC 091148
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
248 AM AKST Thu Nov 9 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.

PKZ199-100045-
248 AM AKST Thu Nov 9 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

High pressure moves into the Eastern Bering by Sat morning. A 987
mb Russian Far East low extends a front over the Western Bering 
that slips through the Bering Strait for Sat morning. The trailing
front approaches the Western Aleutians Sat morning.

$$

PKZ150-100045-
South of the AK Peninsula Sitkinak to Castle Cape-
248 AM AKST Thu Nov 9 2017

...GALE WARNING TONIGHT AND FRIDAY...

.TODAY...W wind 20 kt becoming NW 30 kt in the afternoon. Gusts to 40
kt out of bays and passes. Seas 10 ft.
.TONIGHT...NW wind 25 kt except 35 kt E of Chirikof Island. Seas 11 
ft.
.FRI...NW wind 30 kt except 40 kt E of Chirikof Island. Seas 12 ft.
.FRI NIGHT...NW wind 40 kt. Seas 12 ft.
.SAT...NW wind 40 kt. Seas 12 ft.
.SUN THROUGH MON...NW wind 30 kt. Seas 9 ft.

$$

PKZ155-100045-
South of the AK Peninsula Castle Cape to Cape Sarichef-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...W wind 25 kt. Seas 9 ft.
.TONIGHT...NW wind 30 kt. Seas 9 ft.
.FRI...NW wind 30 kt. Seas 8 ft.
.FRI NIGHT...NW wind 30 kt. Seas 8 ft.
.SAT...NW wind 30 kt. Seas 7 ft.
.SUN THROUGH MON...NW wind 25 kt. Seas 5 ft.

$$

PKZ160-100045-
Bristol Bay-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NW wind 25 kt. Seas 9 ft. Rain showers.
.TONIGHT...NW wind 25 kt. Seas 9 ft.
.FRI...NW wind 25 kt. Seas 8 ft.
.FRI NIGHT...NW wind 25 kt. Seas 7 ft.
.SAT THROUGH MON...N wind 25 kt. Seas 7 ft.

$$

PKZ165-100045-
Port Heiden to Cape Sarichef-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NW wind 25 kt. Seas 10 ft.
.TONIGHT...NW wind 30 kt. Seas 11 ft.
.FRI...NW wind 25 kt. Seas 9 ft.
.FRI NIGHT...NW wind 25 kt. Seas 8 ft.
.SAT THROUGH SUN...W wind 25 kt. Seas 7 ft.
.MON...N wind 20 kt. Seas 6 ft.

$$

PKZ170-100045-
Cape Sarichef to Nikolski Bering Side-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...NW wind 20 kt. Seas 10 ft.
.TONIGHT...NW wind 20 kt. Seas 8 ft.
.FRI...W wind 20 kt. Seas 7 ft.
.FRI NIGHT...W wind 15 kt. Seas 6 ft.
.SAT THROUGH SUN...SW wind 15 kt. Seas 6 ft.
.MON...SE wind 20 kt. Seas 5 ft.

$$

PKZ171-100045-
Unalaska Bay-
248 AM AKST Thu Nov 9 2017

.TODAY...NW wind 15 kt. Seas 7 ft.
.TONIGHT...NW wind 15 kt. Seas 5 ft subsiding to 2 ft after
midnight.
.FRI...W wind 15 kt diminishing to 10 kt in the afternoon. Seas
2 ft.
.FRI NIGHT...W wind 10 kt. Seas 2 ft.
.SAT...Variable wind less than 10 kt. Seas 3 ft.
.SUN...SW wind 10 kt. Seas 2 ft.
.MON...SE wind 10 kt. Seas 2 ft.

$$

PKZ172-100045-
Cape Sarichef to Nikolski Pacific Side-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...NW wind 20 kt. Seas 9 ft.
.TONIGHT...NW wind 20 kt. Seas 7 ft.
.FRI...NW wind 20 kt. Seas 6 ft.
.FRI NIGHT...NW wind 20 kt. Seas 5 ft.
.SAT THROUGH SUN...SW wind 15 kt. Seas 6 ft.
.MON...S wind 15 kt. Seas 6 ft.

$$

PKZ173-100045-
Nikloski to Seguam Island Bering Side-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...N wind 15 kt. Seas 8 ft.
.TONIGHT...Variable wind 10 kt. Seas 6 ft.
.FRI...S wind 15 kt. Seas 5 ft.
.FRI NIGHT...S wind 15 kt. Seas 4 ft.
.SAT THROUGH MON...SE wind 20 kt. Seas 7 ft.

$$

PKZ174-100045-
Nikolski to Seguam Island Pacific Side-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY TODAY...

.TODAY...N wind 15 kt. Seas 8 ft.
.TONIGHT...Variable wind 10 kt. Seas 6 ft.
.FRI...SE wind 15 kt. Seas 6 ft.
.FRI NIGHT...SE wind 15 kt. Seas 6 ft.
.SAT THROUGH MON...SE wind 20 kt. Seas 10 ft.

$$

PKZ175-100045-
Seguam Island to Adak Bering Side-
248 AM AKST Thu Nov 9 2017

.TODAY...Variable wind 10 kt. Seas 6 ft.
.TONIGHT...S wind 15 kt. Seas 5 ft.
.FRI...SE wind 20 kt. Seas 4 ft.
.FRI NIGHT...SE wind 25 kt. Seas 5 ft.
.SAT THROUGH MON...SE wind 25 kt. Seas 6 ft.

$$

PKZ176-100045-
Seguam Island to Adak Pacific Side-
248 AM AKST Thu Nov 9 2017

.TODAY...Variable wind 10 kt. Seas 6 ft.
.TONIGHT...SE wind 15 kt. Seas 6 ft.
.FRI...SE wind 20 kt. Seas 7 ft.
.FRI NIGHT...SE wind 25 kt. Seas 10 ft.
.SAT THROUGH MON...SE wind 25 kt. Seas 13 ft.

$$

PKZ177-100045-
Adak to Kiska-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY FRIDAY...

.TODAY...Variable wind less than 10 kt. Seas 5 ft.
.TONIGHT...SE wind 20 kt. Seas 6 ft.
.FRI...SE wind 25 kt. Seas 8 ft.
.FRI NIGHT...SE wind 25 kt. Seas 10 ft.
.SAT THROUGH MON...SE wind 25 kt. Seas 13 ft.

$$

PKZ178-100045-
Kiska to Attu-
248 AM AKST Thu Nov 9 2017

...GALE WARNING TONIGHT...

.TODAY...S wind 20 kt increasing to 30 kt in the afternoon. Seas
7 ft.
.TONIGHT...S wind 35 kt. Seas 11 ft.
.FRI...S wind 30 kt. Seas 13 ft.
.FRI NIGHT...SE wind 30 kt. Seas 13 ft.
.SAT THROUGH SUN...E wind 25 kt. Seas 11 ft.
.MON...SE wind 20 kt. Seas 9 ft.

$$

PKZ179-100045-
Pribilof Islands Near Shore Waters-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH TONIGHT...

.TODAY...NW wind 20 kt. Seas 10 ft.
.TONIGHT...W wind 20 kt. Seas 9 ft.
.FRI...W wind 20 kt. Seas 7 ft.
.FRI NIGHT...W wind 15 kt. Seas 5 ft.
.SAT THROUGH SUN...W wind 15 kt. Seas 7 ft.
.MON...E wind 20 kt. Seas 6 ft.

$$

PKZ180-100045-
Kuskokwim Delta and Etolin Strait-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...NW wind 25 kt. Seas 11 ft.
.TONIGHT...NW wind 25 kt. Seas 10 ft.
.FRI...W wind 25 kt. Seas 8 ft.
.FRI NIGHT...NW wind 25 kt. Seas 8 ft.
.SAT THROUGH SUN...NW wind 25 kt. Seas 7 ft.
.MON...N wind 20 kt. Seas 5 ft.

$$

PKZ181-100045-
North and West of Nunivak Island-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...W wind 30 kt. Seas 11 ft.
.TONIGHT...W wind 25 kt. Seas 10 ft.
.FRI...W wind 25 kt. Seas 8 ft. Rain and snow.
.FRI NIGHT...W wind 25 kt. Seas 8 ft.
.SAT...W wind 30 kt. Seas 9 ft.
.SUN...NW wind 30 kt. Seas 9 ft.
.MON...NE wind 20 kt. Seas 6 ft.

$$

PKZ185-100045-
Saint Matthew Island Waters-
248 AM AKST Thu Nov 9 2017

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...W wind 25 kt. Seas 12 ft.
.TONIGHT...SW wind 25 kt. Seas 10 ft.
.FRI...SW wind 25 kt. Seas 9 ft.
.FRI NIGHT...SW wind 30 kt. Seas 13 ft.
.SAT...W wind 30 kt. Seas 15 ft.
.SUN...N wind 25 kt. Seas 11 ft.
.MON...E wind 30 kt. Seas 12 ft.

$$

NWS Anchorage, AK wrote its last area forecast discussion before this small craft advisory went out at Nov 8, 4:06 PM AKST, 10 hours 42 minutes earlier.

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
406 PM AKST Wed Nov 8 2017

.ANALYSIS AND UPPER LEVELS...
Broad west to southwest flow aloft with weak embedded waves
extends from the western Bering Sea to across Southcentral Alaska.
The waves over the mainland are predominately cloud makers with
only a smattering of showers over the western mainland. The more
significant of the waves in the wave train, located over the
Central Bering Sea this morning, has a developing surface low and
frontal boundary associated with it. It is moving rapidly east and
will be the main weather maker over the next 24-36 hours as it
heads east.

&&

.MODEL DISCUSSION...
Overall, models are in good agreement with the main features,
upper trough and associated weather front, which moves across the
mainland. Models however differ on QPF amounts. Will probably lean
toward the higher resolution models in this regard as well as for
outflow winds across the Gulf coast Thursday night and Friday.

&&

.AVIATION...
PANC...VFR conditions and light winds will continue through tonight.
MVFR to IFR ceiling and visibilities in snow are expected Thursday
afternoon.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Zonal flow aloft will continue through tonight. On Thursday a
trough will push into the area from the west. This system is
moving fairly fast. There does appear to be enough dynamics with
this system to produce some snow for much of Southcentral. This
includes the Anchorage area and the Matanuska valley, with the
flow aloft from the southwest. Accumulations should be fairly
light due to the speed of the system. After this trough passes
through late Thursday, a fairly strong offshore event will begin.
A surface low will form just south of the Kenai Peninsula
Thursday afternoon that will move to the east-southeast through
Friday. Cold advection will help to drive the winds, with the
usual areas (including Seward, Whittier, Valdez) becoming fairly
gusty.

&&

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

A strong upper-level trough stretched from the Chukchi Sea,
through Saint Paul Island, towards the central Aleutians this
afternoon. Water vapor imagery was showing surface low development
has commenced near Saint Paul Island. This low will rapidly
deepen to near 993 mb as it moves ashore in the Golovin area late
this evening, with a strong front extending south from this low.
With very good surface convergence along it seen in the model
data, look for widespread precipitation to develop along this
front as it sweeps eastward through Thursday.

As for precipitation type, that becomes a little tricky once you
get near or just south of the Kuskokwim Delta. Soundings along
the coast in this region show a warm wedge from the surface
through about 2000 feet. However, moderately intense precipitation
rates will allow for some snowflakes to survive the trip through
the melting layer during the first few hours. After that, the
lower levels of the atmosphere will cool enough for a transition
to all snow to occur before the precipitation ends. Most
locations will see 1 to 4 inches of snowfall, with higher amounts
likely once you get closer to the Alaskan Range.

&&

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

A developing surface low near Saint Paul Island will lift north
towards Golovin by late this evening, with an attendant surface
cold front sweeping eastward. Gale force winds will precede this
front across the eastern Bering and adjacent coastal waters of
Southwest Alaska and the Alaska Peninsula. Rain will transition
to snow following frontal passage from west to east, with winds
subsiding behind the front, as a ridge of high pressure builds in
from the west.

&&

.LONG TERM FORECAST (Days 3 through 7)...
Models remain in very good agreement through much of the long term
forecast, with some minor discrepancies out west during the early
part of next week. Models continue to agree and provide higher
confidence in a long-wave ridge over much of the Bering Sea and
Aleutian chain, and a long-wave trough over Southcentral Alaska
and the Gulf Friday night through Monday morning. Several short
wave troughs traverse the top of the ridge, and drop northwest to
southeast across the state during the forecast period. The
strongest of these waves drop through the southern Mainland on
Sunday, providing some strong gusty outflow winds along the
northern Gulf and Alaska Peninsula through Monday. Some light snow
showers are expected to develop as this system tracks through
Southcentral, however the limiting factor on snowfall amounts will
be dependent on how much moisture is available. As of now, there
is limited amounts of moisture available during this time frame,
so we are expecting a quick shot of light snow showers Sunday into
Monday.

The models continue to struggle with regards to the placement and
track of a north Pacific low and its associated front impacting
the western half of the Bering and Aleutians Sunday into the
middle of next week. The slightly faster GFS track was preferred
overall, which the 12Z ECMWF trended toward and WPC guidance
leaned toward today. There remains lower confidence on the timing
and strength of the system overall, but there is higher confidence
in wet and gusty conditions making their way through the western
and central Bering/Aleutians Sunday through Tuesday.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 121 127 130-132 136-138 150 165 170 178-181 351 352
411 414.

&&

SYNOPSIS AND MODEL DISCUSSION...RMC
SOUTHCENTRAL ALASKA...BL
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...P Doll
LONG TERM...Pepe

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.