Small Craft Advisory 281, NWS Anchorage, AK

749 
FZAK52 PAFC 042337
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
337 PM AKDT TUE APR 4 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.

PKZ199-051230-
337 PM AKDT TUE APR 4 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A 977 MB LOW 170 NM SOUTH OF KODIAK ISLANDS DISSIPATES TONIGHT. 
A 968 MB MOVES TO 100 NM SOUTHEAST OF KODIAK ISLAND WED AFTERNOON
THEN WEAKENS TO 977 MB BY THU AFTERNOON. A 1005 MB LOW OVER THE 
CENTRAL BERING MOVES SOUTHEAST AND DISSIPATES WED NIGHT. A 987 MB 
LOW NEAR KAMCHATKA WED AFTERNOON MOVES NEAR SHEMYA THU AFTERNOON.

$$

PKZ150-051230-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
337 PM AKDT TUE APR 4 2017

...GALE WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...NW WIND 30 KT. SEAS 10 FT.
.WED...NW WIND 40 KT. SEAS 14 FT. RAIN AND SNOW.
.WED NIGHT...NW WIND 40 KT. SEAS 14 FT.
.THU AND THU NIGHT...NW WIND 30 KT. SEAS 12 FT.
.FRI...SW WIND 30 KT. SEAS 11 FT.
.SAT...S WIND 15 KT. SEAS 8 FT.
.SUN...SE WIND 20 KT. SEAS 8 FT.

$$

PKZ155-051230-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
337 PM AKDT TUE APR 4 2017

...GALE WARNING THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 35 KT. GUSTS TO 50 KT OUT OF BAYS AND PASSES. 
SEAS 11 FT.
.WED AND WED NIGHT...NW WIND 40 KT. GUSTS TO 55 KT OUT OF BAYS 
AND PASSES. SEAS 12 FT.
.THU AND THU NIGHT...W WIND 35 KT. SEAS 12 FT.
.FRI...W WIND 30 KT. SEAS 10 FT.
.SAT...SW WIND 15 KT. SEAS 9 FT.
.SUN...SE WIND 20 KT. SEAS 7 FT.

$$

PKZ160-051230-
BRISTOL BAY-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...N WIND 20 KT. SEAS IN ICE FREE WATERS 3 FT.
.WED...NW WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT. 
SNOW AND RAIN.
.WED NIGHT...NW WIND 30 KT. SEAS IN ICE FREE WATERS 6 FT. 
SNOW AND RAIN.
.THU...N WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT.
.THU NIGHT...NE WIND 30 KT. SEAS IN ICE FREE WATERS 5 FT.
.FRI...E WIND 30 KT. SEAS IN ICE FREE WATERS 5 FT.
.SAT THROUGH SUN...SE WIND 15 KT. SEAS IN ICE FREE WATERS 3 FT.

$$

PKZ165-051230-
PORT HEIDEN TO CAPE SARICHEF-
337 PM AKDT TUE APR 4 2017

...GALE WARNING WEDNESDAY...

.TONIGHT...NW WIND 30 KT. SEAS 9 FT.
.WED...NW WIND 35 KT. SEAS 10 FT.
.WED NIGHT...NW WIND 30 KT. SEAS 10 FT. SNOW.
.THU...NW WIND 30 KT. SEAS 9 FT.
.THU NIGHT...NW WIND 25 KT. SEAS 9 FT.
.FRI...W WIND 25 KT. SEAS 7 FT.
.SAT...SW WIND 15 KT. SEAS 6 FT.
.SUN...SE WIND 15 KT. SEAS 5 FT.

$$

PKZ170-051230-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 8 FT.
.WED AND WED NIGHT...NW WIND 30 KT. SEAS 9 FT.
.THU AND THU NIGHT...W WIND 25 KT. SEAS 8 FT.
.FRI THROUGH SAT...NW WIND 20 KT. SEAS 7 FT.
.SUN...E WIND 15 KT. SEAS 6 FT.

$$

PKZ171-051230-
UNALASKA BAY-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 8 FT.
.WED AND WED NIGHT...NW WIND 30 KT. SEAS 8 FT.
.THU...NW WIND 25 KT. SEAS 7 FT.
.THU NIGHT...W WIND 15 KT. SEAS 5 FT.
.FRI...NW WIND 15 KT. SEAS 3 FT.
.SAT...W WIND 15 KT. SEAS 2 FT.
.SUN...E WIND 10 KT. SEAS 2 FT.

$$

PKZ172-051230-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
337 PM AKDT TUE APR 4 2017

...GALE WARNING WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...NW WIND 30 KT. SEAS 9 FT.
.WED AND WED NIGHT...NW WIND 35 KT. SEAS 9 FT.
.THU AND THU NIGHT...W WIND 30 KT. SEAS 8 FT.
.FRI...N WIND 20 KT. SEAS 10 FT.
.SAT...SW WIND 20 KT. SEAS 10 FT.
.SUN...E WIND 20 KT. SEAS 10 FT.

$$

PKZ173-051230-
NIKLOSKI TO SEGUAM ISLAND BERING SIDE-
337 PM AKDT TUE APR 4 2017

.TONIGHT...NW WIND 20 KT. SEAS 6 FT.
.WED...NW WIND 20 KT. SEAS 6 FT.
.WED NIGHT...NW WIND 15 KT. SEAS 5 FT.
.THU...W WIND 15 KT. SEAS 5 FT.
.THU NIGHT...SE WIND 20 KT. SEAS 5 FT.
.FRI...N WIND 20 KT. SEAS 7 FT.
.SAT THROUGH SUN...NE WIND 20 KT. SEAS 7 FT.

$$

PKZ174-051230-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW WIND 25 KT. SEAS 7 FT.
.WED...NW WIND 20 KT. SEAS 6 FT.
.WED NIGHT...W WIND 20 KT. SEAS 6 FT.
.THU...W WIND 20 KT. SEAS 6 FT.
.THU NIGHT...SW WIND 30 KT. SEAS 11 FT.
.FRI...NW WIND 30 KT. SEAS 14 FT.
.SAT...SE WIND 20 KT. SEAS 11 FT.
.SUN...NE WIND 20 KT. SEAS 13 FT.

$$

PKZ175-051230-
SEGUAM ISLAND TO ADAK BERING SIDE-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY WEDNESDAY NIGHT...

.TONIGHT...NW WIND 15 KT. SEAS 4 FT.
.WED...W WIND 15 KT. SEAS 4 FT.
.WED NIGHT...W WIND 25 KT. SEAS 6 FT.
.THU...SW WIND 25 KT. SEAS 6 FT.
.THU NIGHT...W WIND 30 KT. SEAS 9 FT.
.FRI...N WIND 25 KT. SEAS 9 FT.
.SAT...NE WIND 25 KT. SEAS 8 FT.
.SUN...N WIND 25 KT. SEAS 8 FT.

$$

PKZ176-051230-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
337 PM AKDT TUE APR 4 2017

.TONIGHT...NW WIND 15 KT. SEAS 5 FT.
.WED...W WIND 20 KT. SEAS 5 FT.
.WED NIGHT...W WIND 20 KT. SEAS 6 FT.
.THU...SW WIND 30 KT. SEAS 10 FT.
.THU NIGHT...W WIND 30 KT. SEAS 14 FT.
.FRI...NW WIND 30 KT. SEAS 14 FT.
.SAT...E WIND 25 KT. SEAS 16 FT.
.SUN...N WIND 25 KT. SEAS 16 FT.

$$

PKZ177-051230-
ADAK TO KISKA-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY WEDNESDAY AND WEDNESDAY NIGHT...

.TONIGHT...W WIND 15 KT. SEAS 4 FT.
.WED...W WIND 15 KT INCREASING TO 25 KT IN THE AFTERNOON. 
SEAS 5 FT.
.WED NIGHT...SW WIND 30 KT. SEAS BUILDING TO 10 FT.
.THU...SW WIND 30 KT. SEAS 14 FT.
.THU NIGHT...W WIND 30 KT. SEAS 15 FT.
.FRI THROUGH SUN...N WIND 25 KT. SEAS 15 FT.

$$

PKZ178-051230-
KISKA TO ATTU-
337 PM AKDT TUE APR 4 2017

...GALE WARNING WEDNESDAY NIGHT...

.TONIGHT...NW WIND 15 KT. SEAS 5 FT.
.WED...W WIND 25 KT. SEAS 6 FT.
.WED NIGHT...SW WIND 35 KT. SEAS 14 FT. SNOW AND RAIN.
.THU...W WIND 30 KT. SEAS 16 FT.
.THU NIGHT...NW WIND 30 KT. SEAS 17 FT.
.FRI...E WIND 20 KT. SEAS 15 FT.
.SAT...N WIND 25 KT. SEAS 14 FT.
.SUN...NE WIND 20 KT. SEAS 10 FT.

$$

PKZ179-051230-
PRIBILOF ISLANDS NEAR SHORE WATERS-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT. 
FREEZING SPRAY.
.WED...NW WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT.
.WED NIGHT...NW WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT. 
FREEZING SPRAY.
.THU...NW WIND 25 KT. SEAS IN ICE FREE WATERS 5 FT.
.THU NIGHT...NW WIND 20 KT. SEAS IN ICE FREE WATERS 3 FT.
.FRI...NW WIND 20 KT. SEAS IN ICE FREE WATERS 6 FT.
.SAT THROUGH SUN...NE WIND 15 KT. SEAS IN ICE FREE WATERS 6 FT.

$$

PKZ180-051230-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
337 PM AKDT TUE APR 4 2017

...BRISK WIND ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 30 KT.
.WED AND WED NIGHT...NW WIND 30 KT.
.THU...NW WIND 30 KT.
.THU NIGHT...N WIND 25 KT.
.FRI...NE WIND 20 KT.
.SAT THROUGH SUN...SE WIND 15 KT.

$$

PKZ181-051230-
NORTH AND WEST OF NUNIVAK ISLAND-
337 PM AKDT TUE APR 4 2017

...BRISK WIND ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT.
.WED AND WED NIGHT...NW WIND 25 KT.
.THU...NW WIND 25 KT.
.THU NIGHT...N WIND 15 KT.
.FRI...N WIND 20 KT.
.SAT...NE WIND 15 KT.
.SUN...VARIABLE WIND 10 KT.

$$

PKZ185-051230-
SAINT MATTHEW ISLAND WATERS-
337 PM AKDT TUE APR 4 2017

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY NIGHT...

.TONIGHT...NW WIND 25 KT. SEAS IN ICE FREE WATERS 2 FT.
.WED...NW WIND 30 KT E OF SAINT MATTHEW ISLAND...NW 20 KT 
W OF SAINT MATTHEW ISLAND. SEAS IN ICE FREE WATERS 2 FT.
.WED NIGHT...NW WIND 25 KT. SEAS IN ICE FREE WATERS 3 FT.
.THU...NW WIND 20 KT. SEAS IN ICE FREE WATERS 3 FT.
.THU NIGHT...N WIND 15 KT. SEAS IN ICE FREE WATERS 4 FT.
.FRI...N WIND 15 KT. SEAS IN ICE FREE WATERS 7 FT.
.SAT...N WIND 25 KT. SEAS IN ICE FREE WATERS 7 FT.
.SUN...NE WIND 20 KT. SEAS IN ICE FREE WATERS 6 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
430 PM AKDT Mon Apr 3 2017

.ANALYSIS AND UPPER LEVELS...

Synoptically, the primary feature of interest is a strong, fully
wrapped up low inching northward towards the Gulf, and its
associated front already causing strong winds and precipitation
along the Gulf Coast and Kodiak. Relatively weak high pressure is
in place across the Bering, with tranquil weather there.

Cloud cover is rapidly spreading north over much of Southern
Alaska as a strong front pushes towards the Gulf Coast. This
morning's scatterometer (satellite derived winds) pass shows a
broad area of gale force winds over much of the central Gulf. A
number of coastal weather stations have reported peak wind gusts
in the 40-50 mph range already today, with stronger gusts still to
come. A broad stratiform shield of precipitation is filling in on
Middleton Island radar imagery. The airport in Kodiak reported
moderate rain earlier this afternoon as wind gusts approached 50
mph.

For inland areas from Anchorage north, upper and mid-level clouds
are lowering and thickening with time as the front approaches. As
a result, many stations are reporting increasing northerly winds
with the tightening pressure gradient. Thus, Anchorage is running
about 5 degrees cooler than yesterday thus far. Despite this, the
front is ushering in a warmer air mass.

In the upper levels, the Gulf low formed as a piece of energy from
a subtropical jet racing off the North Pacific spun off into the
occluded low that is now presently over the Gulf. Comparatively
speaking, the Bering side is very quiet. Broad northerly flow
around the periphery of the Gulf low continues to keep a cold air
mass in place across the region. A vast stratus deck encompasses
most of the Bering. The Saint Paul sounding shows why, with two
inversions in the lower atmosphere capping three unstable layers.
Thus, cold air relative to the warm waters is quite effectively
extracting moisture from the sea surface, but the presence of the
capping inversions is confining the amount of atmosphere being
moistened to the lowest part of the atmosphere. Widespread stratus
is the result.

Finally, across the western Bering through the central Aleutians,
a far more unstable air mass is in place as evidenced by the
Shemya sounding. The result atmospherically is exactly what we are
seeing on satellite, much more patchy cloud cover dominated by
cumulus.

&&

.MODEL DISCUSSION...

On the synoptic scale, all of the models are in agreement on the
track and positioning of the Gulf low over the next couple days.
There are some minor differences by Wednesday afternoon as to
where any associated fronts will be and their strength. Due to
the small scale of those differences, however, high resolution
versions of the NAM/GFS were used to help iron out small scale
wind effects. The changes in the winds through southern Alaska's
many bays and passes remains the primary forecast challenge in
this environment. Thus, overall forecast confidence is high with
less confidence in local effects.

&&

.AVIATION...
PANC...VFR conditions are expected to persist through Tue
morning. Generally light northerly winds are expected to continue
into Tue afternoon. Weak directional wind shear may develop this
evening as winds around 2000 ft becoming southeasterly. These
conditions will last through Tue morning.

&&
.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...

A frontal boundary is quickly pushing north across the Gulf of
Alaska this afternoon ahead of a sub 970 mb low in the North
Pacific. Buoy 46001 in the southern Gulf has reported winds
upwards to 50 kts and should continue to bring winds of anywhere
from 45 to 55 kt to much of the Gulf of Alaska this evening
through Tuesday morning. The front will weaken rapidly Tuesday
morning as it clashes the the coastal mountains. A second area of
low pressure (currently 650 miles south of the low responsible for
the front in the Gulf of Alaska) will rotate around the low
pressure system in the southern Gulf of Alaska Tuesday afternoon
and push into the Gulf Wednesday morning. This will bring another
round of Gale force winds to much of the Gulf while Kodiak
Island, Prince William Sound and the Kenai Peninsula will see yet
another round of ample rainfall. Snow levels will rise to 1K ft
to 2K ft along the Gulf Coast by Wednesday which reinforces that
chances for heavy rainfall at sea level while locations above 2K ft
could see a decent dumping of snowfall. Temperatures will
continue to warm through the forecast period with continued warm
air advection from the south. Temps approaching or exceeding the
mid 40s will be common Tuesday and Wednesday with low temperatures
near or above freezing.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
The strong low approaching the south end of Kodiak Island will
push a front across the Aleutian Range this evening, with
light precipitation spreading into western portions of Bristol Bay
tonight and then into the Kuskokwim Delta on Tuesday. Snow will
quickly mix with rain across Bristol Bay as warmer air moves into
the region, helping to mitigate any accumulation. The delta will
likely stay cold enough to remain all snow, with potential for
minor accumulations in the Bethel area. Downsloping will keep
areas along the western slopes of the Alaska/Aleutian ranges
mostly dry. Another system moving into the gulf will maintain a
showery pattern across the southwest mainland through Wednesday.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
The front along the Pacific side of the Akpen will begin to
weaken this evening as it pushes inland, with heavier
precipitation gradually spreading westward towards Cold Bay by
morning. Strong north to northwest flow will then persist across
the eastern Bering through Wednesday as low pressure remains
parked south of Kodiak Island. This will support widespread snow
showers over the Akpen, with several inches of accumulation
possible by Wednesday afternoon. More benign showery conditions
will continue across the rest of the Bering as a weak low remains
over the area.

&&

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

The extended forecast period beginning Wednesday evening will
feature a continued active Pacific Jet stream in the vicinity of
40N with a high latitude blocking high over the North Slope. There
will be weakening near-Gale force low near Kodiak Island with
rain along the coast. This will set in motion another rather
quiet weather pattern as the low near Kodiak Island weakens
slowly and the storm track shifts south again. Rain and snow
shower threats will be possible inland, but right now, they look
rather meager since the low will be falling apart as some moisture
aloft moves inland. Otherwise, this pattern will feature slightly
above normal temperatures with a continuation of the slow spring
thaw through the weekend.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 125 140 155 160 172.
		 Storm 119 120 130 131 138 139.

&&

SYNOPSIS AND MODEL DISCUSSION...JW/BC
SOUTHCENTRAL ALASKA...MC
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...JA