Small Craft Advisory 973, NWS Anchorage, AK

013 
FZAK52 PAFC 090016
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
316 PM AKST THU DEC 8 2016

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.

PKZ199-091345-
316 PM AKST THU DEC 8 2016
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A STRONG FRONT APPROACHES THE WESTERN ALEUTIANS LATE
TONIGHT...THEN MOVES INTO THE CENTRAL ALEUTIANS AND WESTERN BERING
BY SAT. HIGH PRESSURE OVER THE CENTRAL BERING MOVES TO THE EASTERN
BERING BY SAT.

$$

PKZ150-091345-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...N WIND 25 KT. SEAS 6 FT. SNOW SHOWERS.
.FRI...NW WIND 20 KT. SEAS 6 FT.
.FRI NIGHT...NE WIND 20 KT. SEAS 7 FT. RAIN SHOWERS.
.SAT...NE WIND 20 KT. SEAS 7 FT.
.SAT NIGHT...NE WIND 15 KT. SEAS 7 FT.
.SUN...VARIABLE WIND 10 KT. SEAS 5 FT.
.MON THROUGH TUE...NE WIND 15 KT. SEAS 5 FT.

$$

PKZ155-091345-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...NW WIND 20 KT. SEAS 5 FT. FREEZING SPRAY W OF THE
SHUMAGIN ISLANDS.
.FRI...NW WIND 25 KT. SEAS 6 FT.
.FRI NIGHT...NW WIND 30 KT. SEAS 8 FT.
.SAT...N WIND 20 KT. SEAS 7 FT.
.SAT NIGHT...SE WIND 15 KT. SEAS 6 FT.
.SUN...SE WIND 20 KT. SEAS 7 FT.
.MON...E WIND 15 KT. SEAS 6 FT.
.TUE...E WIND 20 KT. SEAS 12 FT.

$$

PKZ160-091345-
BRISTOL BAY-
316 PM AKST THU DEC 8 2016

...HEAVY FREEZING SPRAY WARNING THROUGH FRIDAY...

.TONIGHT...NE WIND 20 KT. SEAS IN ICE FREE WATERS 3 FT. HEAVY
FREEZING SPRAY.
.FRI...N WIND 20 KT. SEAS IN ICE FREE WATERS 4 FT. HEAVY FREEZING
SPRAY. SNOW SHOWERS.
.FRI NIGHT...N WIND 20 KT. SEAS IN ICE FREE WATERS 4 FT. FREEZING
SPRAY. SNOW SHOWERS.
.SAT AND SAT NIGHT...NE WIND 15 KT. SEAS IN ICE FREE WATERS 3 FT.
.SUN...E WIND 15 KT. SEAS IN ICE FREE WATERS 3 FT.
.MON THROUGH TUE...NE WIND 20 KT. SEAS IN ICE FREE WATERS 6 FT.

$$

PKZ165-091345-
PORT HEIDEN TO CAPE SARICHEF-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...N WIND 15 KT. SEAS 6 FT. FREEZING SPRAY.
.FRI...N WIND 25 KT. SEAS 7 FT. FREEZING SPRAY.
.FRI NIGHT...N WIND 25 KT. SEAS 8 FT. FREEZING SPRAY.
.SAT...NE WIND 15 KT. SEAS 6 FT.
.SAT NIGHT...SE WIND 15 KT. SEAS 4 FT.
.SUN THROUGH TUE...E WIND 20 KT. SEAS 6 FT.

$$

PKZ170-091345-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY...

.TONIGHT...NW WIND 20 KT. SEAS 7 FT.
.FRI...N WIND 25 KT. SEAS 7 FT.
.FRI NIGHT...N WIND 20 KT. SEAS 7 FT.
.SAT...E WIND 15 KT. SEAS 6 FT.
.SAT NIGHT...SE WIND 25 KT. SEAS 5 FT.
.SUN THROUGH TUE...SE WIND 25 KT. SEAS 9 FT.

$$

PKZ171-091345-
UNALASKA BAY-
316 PM AKST THU DEC 8 2016

.TONIGHT...NW WIND 10 KT INCREASING TO 15 KT AFTER MIDNIGHT. SEAS
3 FT BUILDING TO 5 FT AFTER MIDNIGHT.
.FRI...NW WIND 20 KT. SEAS 6 FT.
.FRI NIGHT...NW WIND 15 KT. SEAS 5 FT SUBSIDING TO 3 FT AFTER
MIDNIGHT.
.SAT...E WIND 10 KT. SEAS 3 FT.
.SAT NIGHT...SE WIND 20 KT. SEAS 3 FT.
.SUN...SE WIND 20 KT. SEAS 3 FT.
.MON THROUGH TUE...SE WIND 15 KT. SEAS 2 FT.

$$

PKZ172-091345-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...NW WIND 20 KT. SEAS 6 FT.
.FRI...N WIND 25 KT. SEAS 6 FT.
.FRI NIGHT...N WIND 25 KT. SEAS 7 FT.
.SAT...E WIND 20 KT. SEAS 5 FT.
.SAT NIGHT...SE WIND 25 KT. SEAS 11 FT.
.SUN THROUGH MON...SE WIND 25 KT. SEAS 12 FT.
.TUE...SE WIND 25 KT. SEAS 18 FT.

$$

PKZ173-091345-
NIKOLSKI TO SEGUAM ISLAND BERING SIDE-
316 PM AKST THU DEC 8 2016

.TONIGHT...VARIABLE WIND 10 KT. SEAS 6 FT.
.FRI...NE WIND 15 KT. SEAS 6 FT.
.FRI NIGHT...E WIND 20 KT. SEAS 6 FT.
.SAT AND SAT NIGHT...SE WIND 30 KT. SEAS 9 FT.
.SUN...SE WIND 30 KT. SEAS 9 FT.
.MON THROUGH TUE...SE WIND 30 KT. SEAS 18 FT.

$$

PKZ174-091345-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY NIGHT...

.TONIGHT...VARIABLE WIND 10 KT. SEAS 7 FT.
.FRI...NE WIND 15 KT. SEAS 7 FT.
.FRI NIGHT...SE WIND 25 KT. SEAS 6 FT.
.SAT...SE WIND 30 KT. SEAS 11 FT.
.SAT NIGHT...SE WIND 25 KT. SEAS 12 FT.
.SUN...S WIND 25 KT. SEAS 12 FT.
.MON THROUGH TUE...SE WIND 30 KT. SEAS 22 FT.

$$

PKZ175-091345-
SEGUAM ISLAND TO ADAK BERING SIDE-
316 PM AKST THU DEC 8 2016

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 8 FT.
.FRI...E WIND 15 KT INCREASING TO 25 KT IN THE AFTERNOON. 
SEAS 7 FT.
.FRI NIGHT...E WIND 35 KT. SEAS 9 FT.
.SAT...E WIND 35 KT. SEAS 10 FT.
.SAT NIGHT...SE WIND 30 KT. SEAS 10 FT.
.SUN...SE WIND 30 KT. SEAS 8 FT.
.MON THROUGH TUE...SE WIND 30 KT. SEAS 16 FT.

$$

PKZ176-091345-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
316 PM AKST THU DEC 8 2016

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 10 FT. RAIN.
.FRI...E WIND 15 KT INCREASING TO 25 KT IN THE AFTERNOON. 
SEAS 9 FT.
.FRI NIGHT...SE WIND 35 KT. SEAS 11 FT.
.SAT...SE WIND 35 KT. SEAS 14 FT.
.SAT NIGHT...S WIND 25 KT. SEAS 13 FT.
.SUN...S WIND 30 KT. SEAS 12 FT.
.MON THROUGH TUE...SE WIND 30 KT. SEAS 24 FT.

$$

PKZ177-091345-
ADAK TO KISKA-
316 PM AKST THU DEC 8 2016

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...NW WIND 20 KT IN THE EVENING BECOMING NE 25 KT. SEAS
12 FT.
.FRI...E WIND 30 KT. SEAS 10 FT.
.FRI NIGHT...E WIND 40 KT. SEAS 15 FT. RAIN.
.SAT...E WIND 35 KT. SEAS 15 FT.
.SAT NIGHT...SE WIND 30 KT. SEAS 12 FT.
.SUN...S WIND 30 KT. SEAS 13 FT.
.MON...SE WIND 30 KT. SEAS 20 FT.
.TUE...SE WIND 25 KT. SEAS 18 FT.

$$

PKZ178-091345-
KISKA TO ATTU-
316 PM AKST THU DEC 8 2016

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...NE WIND 15 KT BECOMING E 35 KT AFTER MIDNIGHT. SEAS
12 FT.
.FRI...E WIND 40 KT. SEAS 17 FT. RAIN.
.FRI NIGHT...E WIND 40 KT. SEAS 18 FT. RAIN.
.SAT...E WIND 35 KT. SEAS 16 FT.
.SAT NIGHT...SE WIND 30 KT. SEAS 13 FT.
.SUN...S WIND 35 KT. SEAS 15 FT.
.MON...SE WIND 25 KT. SEAS 14 FT.
.TUE...S WIND 20 KT. SEAS 13 FT.

$$

PKZ179-091345-
PRIBILOF ISLANDS NEAR SHORE WATERS-
316 PM AKST THU DEC 8 2016

.TONIGHT...N WIND 20 KT. SEAS 7 FT. FREEZING SPRAY.
.FRI...NE WIND 20 KT. SEAS 7 FT. FREEZING SPRAY.
.FRI NIGHT...N WIND 15 KT. SEAS 6 FT. FREEZING SPRAY.
.SAT...VARIABLE WIND 10 KT. SEAS 5 FT.
.SAT NIGHT...SE WIND 15 KT. SEAS 4 FT.
.SUN...SE WIND 25 KT. SEAS 10 FT.
.MON THROUGH TUE...SE WIND 20 KT. SEAS 14 FT.

$$

PKZ180-091345-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY FRIDAY AND FRIDAY NIGHT...

.TONIGHT...NE WIND 20 KT. SEAS IN ICE FREE WATERS 4 FT. FREEZING
SPRAY.
.FRI AND FRI NIGHT...N WIND 25 KT. SEAS IN ICE FREE WATERS 6 FT.
FREEZING SPRAY.
.SAT...NE WIND 10 KT. SEAS IN ICE FREE WATERS 4 FT.
.SAT NIGHT...E WIND 15 KT. SEAS IN ICE FREE WATERS 3 FT.
.SUN THROUGH MON...E WIND 20 KT. SEAS IN ICE FREE WATERS 6 FT.
.TUE...E WIND 20 KT. SEAS IN ICE FREE WATERS 10 FT.

$$

PKZ181-091345-
NORTH AND WEST OF NUNIVAK ISLAND-
316 PM AKST THU DEC 8 2016

...HEAVY FREEZING SPRAY WARNING TONIGHT...
...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NE WIND 25 KT EARLY DIMINISHING TO 15 KT. SEAS IN ICE
FREE WATERS 6 FT. HEAVY FREEZING SPRAY.
.FRI...NE WIND 20 KT. SEAS IN ICE FREE WATERS 5 FT. FREEZING
SPRAY.
.FRI NIGHT...N WIND 20 KT. SEAS IN ICE FREE WATERS 5 FT. FREEZING
SPRAY.
.SAT...NE WIND 20 KT. SEAS IN ICE FREE WATERS 5 FT.
.SAT NIGHT...E WIND 15 KT. SEAS IN ICE FREE WATERS 4 FT.
.SUN THROUGH TUE...E WIND 20 KT. SEAS IN ICE FREE WATERS 10 FT.

$$

PKZ185-091345-
SAINT MATTHEW ISLAND WATERS-
316 PM AKST THU DEC 8 2016

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...E WIND 25 KT. SEAS 12 FT. FREEZING SPRAY.
.FRI...NE WIND 15 KT. SEAS 9 FT. FREEZING SPRAY.
.FRI NIGHT...NE WIND 20 KT. SEAS 7 FT.
.SAT AND SAT NIGHT...E WIND 20 KT. SEAS 6 FT.
.SUN...SE WIND 30 KT. SEAS 11 FT.
.MON THROUGH TUE...SE WIND 25 KT. SEAS 18 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion...UPDATED
National Weather Service Anchorage AK
609 PM AKST Wed Dec 7 2016

.ANALYSIS AND UPPER LEVELS...
A high amplitude Ridge over the Bering sea is blocking the
approach of systems from the west while a cold upper level trough
remains nearly stationary over the eastern Interior and
Southcentral Alaska. At the surface there is high pressure over
the northern half of the state and through the central Bering Sea
with a broad complex low in the Gulf of Alaska. This is a typical
pattern for this time of year and is increasing the pressure
gradient in Southwest mainland Alaska as well as along the north
Gulf coast.

&&

.MODEL DISCUSSION...
Models are continuing to be in good agreement with a stable
synoptic pattern over the state. The one wild card remain in the
Gulf of Alaska with the complex low. While this low will persist
the details on the movement of the individual waves is causing a
large range of forecasted snowfall amounts along the north Gulf
Coast and especially Kodiak Island. Over Kodiak, the GFS and NAM
differ on predicted snow amounts with the NAM showing three to
four times the amounts from the GFS. Looking through the detail,
the lower GFS values seem more reasonable.

&&

.AVIATION...
PANC...Periods of light snow will occur into the evening with
some warm air over-running the cold air in place over the
Anchorage bowl. This pattern will allow ceilings and visibilities
to remain mainly VFR with only a chance of occasional marginal
conditions. Winds will continue to be from the north for the
foreseeable future.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A cold upper level low remains the focus for precipitation across
the Gulf of Alaska and Kodiak Island. 850-500mb lapse rates are
fairly steep, with the 00Z Kodiak sounding showing 7.9 degrees
C/km. Thus, the character of precipitation is showery. A weak
upper wave is headed westward across the Kenai Peninsula this
afternoon, but with dry low level northerly flow, don't expect
anything more than flurries or very light snow from the Western
Kenai Peninsula up to Anchorage and the Mat-Su. There is also some
low to mid level isentropic lift, as marginally warmer air
overrides the deep arctic air sitting over interior Southcentral.
This will continue to produce some persistent light snow over
portions of the Copper River Basin.

The next feature of interest is an inverted surface trough sitting
over the Eastern Gulf. This will bring snow to the Copper River
Basin and Prince William Sound region on Thursday. A 20 to 30 kt
low level jet will advect warmer and moister air northward and
combine with strong low level convergence along the trough axis
to produce moderate snow in places. The cold air in place will
produce a low density snow, which is favorable for blowing snow
and reduced visibilities. With persistent strong winds through
Thompson Pass have issued a Blizzard Warning for this event.

Forecast confidence starts out high, but quickly drops to low
Thursday Night and Friday. The trough and associated forcing for
snow will weaken as it rotates westward, with a building ridge
rapidly taking its place. The question is how fast does it weaken
and how far west does the snow spread. For now have introduced a
chance of snow from the Western Kenai to Anchorage and the
Matanuska Valley. There is potential for light accumulation of
snow, though the persistent dry northerly flow will work against
this idea.

&&

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

The pattern for the southwest mainland will largely be
characterized by dry offshore flow through Thursday on the
backside of the trough centered over the western Gulf. This will
yield frigid temperatures beneath mostly clear skies, although
numerous disturbances embedded in the upper level flow will
continue to provide chances for periodic cloud cover over the
Bristol Bay region. Persistent gusty winds will lead to very cold
wind chill values across the Kuskokwim Delta, although these
conditions are not expected to meet advisory criteria at this
time.

&&

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

Cold, offshore north to northeasterly flow over the near-shore ice
will allow for continued sea-effect snow showers to continue over
the southeastern Bering over the next several periods, and also
allow for continued freezing spray issues. Easterly waves will
begin to undercut the ridging to the north and west over the
Bering region and allow for increasing precipitation chances for
the Alaska Peninsula Thursday night into Saturday.

Meanwhile, on the western side of the high pressure ridge, the
gale-force front across the western Bering and Western Aleutians
will continue to weaken as it slowly moves into the high pressure
downstream. As this front gets sheared apart, low pressure will
develop over the southern Bering and move across the Central
Aleutians late Thursday into Friday, bringing small-craft-
advisory-level winds. This front will dissipate by Friday as
easterly flow overtakes the region ahead of a stronger front that
will attempt to push north toward the Western Aleutians later
Friday. Models are beginning to diverge with how far the front
makes it to the Aleutians through the end of the week.

&&

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

High latitude blocking ridge will be the dominant mode across the
Alaska region for the beginning of the weekend and into the middle
of next week, as a stout upper high builds across northern
Alaska. Even though temperatures aloft will actually be warming in
response to this feature, temperatures at the surface will be
dominated by increasing inversions. Temperatures will once again
fall below climatological norms by the weekend as skies clear and
outflow winds persist into next week. While the numerical models
differ in the exact details for much of next week, the ensemble
and multi-model approach all depicts similar sensible weather
solutions as the ridging rebuilds across the eastern Bering Sea
and western Alaska. Offshore flow will remain dominant across
Southern Alaska with no precipitation events expected in the
foreseeable future for inland locales. In other words, continued
cold and dry conditions over much of the mainland, with the main
storm track over Siberia and the Western Aleutians and Western
Bering Sea.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Blizzard warning Thompson Pass.
MARINE...Gales 127 128 138 139 177 128 411. Heavy Freezing Spray
160 180 181.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...SB
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CC
LONG TERM...JA/TP