Small Craft Advisory 152, NWS Anchorage, AK

297 
FZAK52 PAFC 200051
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
351 PM AKST SUN FEB 19 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.

PKZ199-201400-
351 PM AKST SUN FEB 19 2017
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...

BOGOSLOF VOLCANO 53 NM WEST OF DUTCH HARBOR REMAINS ACTIVE. A 968
MB NORTH PACIFIC LOW MOVES TO 35 NM NORTHEAST OF ATTU AT 953 MB
MON MORNING CONTINUING TO THE KAMCHATKA COAST AT 962 MB BY TUE
AFTERNOON. THE ASSOCIATED FRONT PUSHES TO THE ALASKA PENINSULA BY
TUE AFTERNOON. A 965 MB NORTH PACIFIC LOW MOVES TO 95 NM WEST OF
ATTU AT 954 MB TUE AFTERNOON. ITS ASSOCIATED FRONT SWEEPS TO THE
CENTRAL ALEUTIANS BY TUE AFTERNOON.

$$

PKZ150-201400-
SOUTH OF THE AK PENINSULA SITKINAK TO CASTLE CAPE-
351 PM AKST SUN FEB 19 2017

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

.TONIGHT...NW WIND 25 KT. SEAS 6 FT. HEAVY FREEZING SPRAY NEAR
THE COAST.
.MON...NW WIND 25 KT. SEAS 5 FT. FREEZING SPRAY.
.MON NIGHT...NW WIND 20 KT. SEAS 4 FT.
.TUE...S WIND 30 KT. SEAS 9 FT.
.TUE NIGHT...SW WIND 30 KT. SEAS 13 FT.
.WED...SW WIND 25 KT. SEAS 12 FT.
.THU...S WIND 30 KT. SEAS 13 FT.
.FRI...SW WIND 20 KT. SEAS 13 FT.

$$

PKZ155-201400-
SOUTH OF THE AK PENINSULA CASTLE CAPE TO CAPE SARICHEF-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY NIGHT...

.TONIGHT...N WIND 20 KT. SEAS 6 FT. FREEZING SPRAY.
.MON...SE WIND 20 KT. FROM THE SHUMAGIN ISLANDS E... N WIND 15 KT
IN THE MORNING BECOMING VARIABLE 10 KT. SEAS 5 FT.
.MON NIGHT...SE WIND 35 KT...SEAS 7 FT BUILDING TO 13 FT AFTER
MIDNIGHT. FROM THE SHUMAGIN ISLANDS E...VARIABLE WIND 10 KT
BECOMING SE 20 KT AFTER MIDNIGHT...SEAS 4 FT. FREEZING SPRAY.
SNOW.
.TUE...S WIND 30 KT. SEAS 15 FT.
.TUE NIGHT...SW WIND 30 KT. SEAS 15 FT.
.WED THROUGH THU...S WIND 35 KT. SEAS 18 FT.
.FRI...SW WIND 20 KT. SEAS 14 FT.

$$

PKZ160-201400-
BRISTOL BAY-
351 PM AKST SUN FEB 19 2017

.TONIGHT...N WIND 10 KT.
.MON...NE WIND 10 KT.
.MON NIGHT...E WIND 20 KT.
.TUE...E WIND 30 KT.
.TUE NIGHT...SE WIND 25 KT.
.WED THROUGH THU...S WIND 25 KT.
.FRI...SW WIND 15 KT.

$$

PKZ165-201400-
PORT HEIDEN TO CAPE SARICHEF-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING TONIGHT AND MON NIGHT...

.TONIGHT...N WIND 15 KT. SEAS 4 FT. HEAVY FREEZING SPRAY FROM
PORT MOLLER E.
.MON...E WIND 20 KT EXCEPT E 10 KT FROM PORT MOLLER E. SEAS 3 FT.
FREEZING SPRAY.
.MON NIGHT...SE WIND 35 KT EXCEPT E 25 KT FROM PORT MOLLER E. SEAS
7 FT. HEAVY FREEZING SPRAY FROM PORT MOLLER E. SNOW.
.TUE...SE WIND 30 KT. SEAS 7 FT.
.TUE NIGHT...SW WIND 30 KT. SEAS 9 FT.
.WED...S WIND 35 KT. SEAS 11 FT.
.THU...S WIND 30 KT. SEAS 10 FT.
.FRI...SW WIND 20 KT. SEAS 9 FT.

$$

PKZ170-201400-
CAPE SARICHEF TO NIKOLSKI BERING SIDE-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...E WIND 20 KT. SEAS 4 FT. FREEZING SPRAY.
.MON...SE WIND INCREASING TO 40 KT. SEAS 6 FT BUILDING TO 10 FT
IN THE AFTERNOON. FREEZING SPRAY. SNOW.
.MON NIGHT...SE WIND 40 KT. SEAS 12 FT. FREEZING SPRAY E OF
UNALASKA. SNOW AND RAIN.
.TUE...SW WIND 25 KT. SEAS 10 FT.
.TUE NIGHT...S WIND 35 KT. SEAS 13 FT.
.WED...S WIND 40 KT. SEAS 15 FT.
.THU THROUGH FRI...S WIND 25 KT. SEAS 10 FT.

$$

PKZ171-201400-
UNALASKA BAY-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...NE WIND 10 KT. SEAS 3 FT.
.MON...SE WIND 20 KT INCREASING TO 35 KT IN THE AFTERNOON. SEAS 3
FT BUILDING TO 5 FT. SNOW.
.MON NIGHT...SE WIND 35 KT. SEAS 5 FT. SNOW AND RAIN.
.TUE...SW WIND 15 KT. SEAS 2 FT.
.TUE NIGHT...S WIND 25 KT. SEAS 4 FT.
.WED...S WIND 30 KT. SEAS 5 FT.
.THU THROUGH FRI...S WIND 15 KT. SEAS 2 FT.

$$

PKZ172-201400-
CAPE SARICHEF TO NIKOLSKI PACIFIC SIDE-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...NE WIND 15 KT BECOMING E 25 KT AFTER MIDNIGHT. SEAS 4
FT. FREEZING SPRAY.
.MON...SE WIND INCREASING TO 40 KT. SEAS 7 FT BUILDING TO 14 FT
IN THE AFTERNOON. SNOW AND RAIN.
.MON NIGHT...SE WIND 40 KT. SEAS 17 FT. SNOW AND RAIN.
.TUE...W WIND 25 KT. SEAS 16 FT.
.TUE NIGHT...S WIND 35 KT. SEAS 18 FT.
.WED...S WIND 40 KT. SEAS 24 FT.
.THU...SW WIND 30 KT. SEAS 22 FT.
.FRI...SW WIND 20 KT. SEAS 14 FT.

$$

PKZ173-201400-
NIKLOSKI TO SEGUAM ISLAND BERING SIDE-
351 PM AKST SUN FEB 19 2017

...GALE WARNING THROUGH MONDAY...

.TONIGHT...SE WIND 25 KT INCREASING TO 40 KT AFTER MIDNIGHT. SEAS
5 FT BUILDING TO 11 FT. FREEZING SPRAY.
.MON...SE WIND 45 KT. SEAS 16 FT. RAIN AND SNOW.
.MON NIGHT...SW WIND 25 KT. SEAS 14 FT. RAIN.
.TUE...SW WIND 30 KT. SEAS 11 FT.
.TUE NIGHT...S WIND 35 KT. SEAS 15 FT.
.WED...S WIND 40 KT. SEAS 18 FT.
.THU...S WIND 25 KT. SEAS 14 FT.
.FRI...S WIND 30 KT. SEAS 11 FT.

$$

PKZ174-201400-
NIKOLSKI TO SEGUAM ISLAND PACIFIC SIDE-
351 PM AKST SUN FEB 19 2017

...GALE WARNING THROUGH MONDAY...

.TONIGHT...SE WIND 25 KT INCREASING TO 40 KT AFTER MIDNIGHT. SEAS
5 FT BUILDING TO 11 FT.
.MON...S WIND 45 KT. SEAS 17 FT. RAIN AND SNOW.
.MON NIGHT...W WIND 30 KT. SEAS 18 FT.
.TUE...SW WIND 35 KT. SEAS 18 FT.
.TUE NIGHT...S WIND 40 KT. SEAS 24 FT.
.WED...S WIND 45 KT. SEAS 26 FT.
.THU...SW WIND 25 KT. SEAS 22 FT.
.FRI...S WIND 30 KT. SEAS 15 FT.

$$

PKZ175-201400-
SEGUAM ISLAND TO ADAK BERING SIDE-
351 PM AKST SUN FEB 19 2017

...STORM WARNING TONIGHT...

.TONIGHT...SE WIND 40 KT INCREASING TO 50 KT AFTER MIDNIGHT. SEAS
10 FT BUILDING TO 16 FT. SNOW AND RAIN.
.MON...SE WIND 45 KT BECOMING SW 30 KT IN THE AFTERNOON. SEAS 16
FT. RAIN.
.MON NIGHT...SW WIND 25 KT. SEAS 11 FT.
.TUE...S WIND 35 KT. SEAS 13 FT.
.TUE NIGHT...S WIND 40 KT. SEAS 15 FT.
.WED...S WIND 35 KT. SEAS 15 FT.
.THU...S WIND 30 KT. SEAS 11 FT.
.FRI...S WIND 35 KT. SEAS 15 FT.

$$

PKZ176-201400-
SEGUAM ISLAND TO ADAK PACIFIC SIDE-
351 PM AKST SUN FEB 19 2017

...STORM WARNING TONIGHT...

.TONIGHT...SE WIND INCREASING TO 50 KT. SEAS 13 FT BUILDING TO 18
FT AFTER MIDNIGHT. RAIN AND SNOW.
.MON...S WIND 40 KT BECOMING SW 25 KT IN THE AFTERNOON. SEAS 16 FT
BUILDING TO 22 FT. RAIN.
.MON NIGHT...SW WIND 25 KT. SEAS 22 FT.
.TUE...S WIND 40 KT. SEAS 21 FT.
.TUE NIGHT...S WIND 40 KT. SEAS 28 FT.
.WED...S WIND 40 KT. SEAS 27 FT.
.THU...S WIND 30 KT. SEAS 20 FT.
.FRI...S WIND 35 KT. SEAS 18 FT.

$$

PKZ177-201400-
ADAK TO KISKA-
351 PM AKST SUN FEB 19 2017

...STORM WARNING THROUGH MONDAY...

.TONIGHT...SE WIND INCREASING TO 60 KT. SEAS 24 FT. RAIN AND
SNOW.
.MON...S WIND 55 KT BECOMING SW 45 KT IN THE AFTERNOON. SEAS 25 FT
BERING SIDE...34 FT PACIFIC SIDE.
.MON NIGHT...SW WIND 35 KT. SEAS 25 FT. SNOW.
.TUE AND TUE NIGHT...S WIND 45 KT. SEAS 26 FT.
.WED THROUGH THU...S WIND 35 KT. SEAS 22 FT.
.FRI...S WIND 40 KT. SEAS 24 FT.

$$

PKZ178-201400-
KISKA TO ATTU-
351 PM AKST SUN FEB 19 2017

...STORM WARNING THROUGH MONDAY...

.TONIGHT...E WIND INCREASING TO 55 KT. SEAS 18 FT BUILDING TO 27
FT AFTER MIDNIGHT. WIDESPREAD RAIN SHOWERS.
.MON...SE WIND 55 KT BECOMING SW IN THE AFTERNOON. SEAS 32 FT.
RAIN SHOWERS.
.MON NIGHT...SW WIND 45 KT. SEAS 30 FT. SNOW.
.TUE...SE WIND 35 KT. SEAS 19 FT.
.TUE NIGHT...SW WIND 35 KT. SEAS 24 FT.
.WED THROUGH THU...S WIND 35 KT. SEAS 24 FT.
.FRI...S WIND 40 KT. SEAS 28 FT.

$$

PKZ179-201400-
PRIBILOF ISLANDS NEAR SHORE WATERS-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...VARIABLE WIND 10 KT BECOMING SE 15 KT AFTER MIDNIGHT.
SEAS 2 FT.
.MON...E WIND 25 KT INCREASING TO 35 KT IN THE AFTERNOON. SEAS 4
FT BUILDING TO 9 FT. FREEZING SPRAY.
.MON NIGHT...E WIND 45 KT. SEAS 14 FT BUILDING TO 19 FT AFTER
MIDNIGHT. FREEZING SPRAY. SNOW.
.TUE...S WIND 40 KT. SEAS 16 FT.
.TUE NIGHT...SE WIND 30 KT. SEAS 12 FT.
.WED...S WIND 35 KT. SEAS 18 FT.
.THU...S WIND 20 KT. SEAS 14 FT.
.FRI...S WIND 25 KT. SEAS 12 FT.

$$

PKZ180-201400-
KUSKOKWIM DELTA AND ETOLIN STRAIT-
351 PM AKST SUN FEB 19 2017

...BRISK WIND ADVISORY MONDAY NIGHT...

.TONIGHT...N WIND 15 KT.
.MON...NE WIND 10 KT INCREASING TO 15 KT IN THE AFTERNOON.
.MON NIGHT...E WIND 25 KT.
.TUE...E WIND 35 KT.
.TUE NIGHT...E WIND 20 KT.
.WED THROUGH THU...S WIND 30 KT.
.FRI...S WIND 20 KT.

$$

PKZ181-201400-
NORTH AND WEST OF NUNIVAK ISLAND-
351 PM AKST SUN FEB 19 2017

...BRISK WIND ADVISORY MONDAY NIGHT...

.TONIGHT...N WIND 10 KT.
.MON...E WIND 15 KT.
.MON NIGHT...E WIND 25 KT.
.TUE AND TUE NIGHT...NE WIND 25 KT.
.WED...SE WIND 30 KT.
.THU...S WIND 20 KT.
.FRI...S WIND 25 KT.

$$

PKZ185-201400-
SAINT MATTHEW ISLAND WATERS-
351 PM AKST SUN FEB 19 2017

...GALE WARNING MONDAY AND MONDAY NIGHT...
...HEAVY FREEZING SPRAY WARNING MONDAY AND MONDAY NIGHT...

.TONIGHT...VARIABLE WIND 10 KT E OF SAINT MATTHEW ISLAND...E 25 KT
W OF SAINT MATTHEW ISLAND. SEAS IN ICE FREE WATERS 4 FT. FREEZING
SPRAY.
.MON...E WIND 25 KT E OF SAINT MATTHEW ISLAND...E 40 KT W OF SAINT
MATTHEW ISLAND. SEAS IN ICE FREE WATERS 6 FT BUILDING TO 10 FT IN
THE AFTERNOON. HEAVY FREEZING SPRAY W OF SAINT MATTHEW ISLAND.
.MON NIGHT...E WIND 30 KT E OF SAINT MATTHEW ISLAND...E 40 KT W OF
SAINT MATTHEW ISLAND. SEAS IN ICE FREE WATERS 18 FT. HEAVY
FREEZING SPRAY W OF SAINT MATTHEW ISLAND.
.TUE...E WIND 40 KT. SEAS IN ICE FREE WATERS 21 FT.
.TUE NIGHT...E WIND 45 KT. SEAS IN ICE FREE WATERS 20 FT.
.WED...SE WIND 45 KT. SEAS IN ICE FREE WATERS 20 FT.
.THU...SE WIND 25 KT. SEAS IN ICE FREE WATERS 16 FT.
.FRI...S WIND 30 KT. SEAS IN ICE FREE WATERS 15 FT.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
438 PM AKST Sat Feb 18 2017

.ANALYSIS AND UPPER LEVELS...
A broad upper level trough is located over the Bering Strait and
continuing southward across the Alaska Peninsula and well into
the Pacific Ocean. Areas east of this trough axis are getting weak
south to southwest flow aloft with areas to the west in generally
northwest flow. The jet stream is remaining well south of the
forecast area.

&&

.MODEL DISCUSSION...
Models are mostly in good agreement with the overall synoptic
pattern. The exception is with a strong low that will move into
the western Aleutians and Bering Sea early next week where the
Canadian model was dismissed due to a storm track that is 400
miles and 10 to 15 mb different from where the other three main
models are clustered. This is one of the those days where the
difference in the details is where the most significant portion of
the forecast decisions are made. Therefore the higher resolution
models are being used to capture the weak upper level disturbances
moving though Bristol Bay and Cook Inlet as well as some of the
outflow winds that should develop in the Gulf Coast region.

&&

.AVIATION...
PANC...The persistent and weak southerly flow up Cook Inlet is
conducive for keeping in the mostly MVFR conditions around the
airport through the night. There may be periods of IFR from some
low clouds or a short time where the lower cloud deck goes
scattered, but it should mostly be MVFR through Sunday morning.

&&

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

Cold air advection at the lower levels of the atmosphere, cyclonic
flow, and embedded midlevel shortwaves moving from southwest to
northeast up Cook Inlet are a recipe for hit-or-miss snow showers
across most of the area today. This general pattern will continue
through the start of the week. There will be a few features that
should act to focus these showers over a certain area, and the
first of those features is a weak shortwave that comes through
upper Cook Inlet late tonight/early Sunday morning. This should
give an extra bit of lift that produces a more widespread - but
still light - area of snow showers around the Anchorage and lower
Mat-Su areas. In fact, as of this writing, snow shower activity is
already starting to increase over the southern Kenai peninsula
likely in response to this shortwave moving into the area.
Accumulations should be minor, but some locations could see an
inch or so by Sunday afternoon. Additionally, with cold advection
slowly getting more established, the patchy fog around Knik Arm experienced
this morning should not recur tonight.

During the day Monday, an upper low currently over the west coast
of Alaska will start to swing more toward the Gulf of Alaska as a
negatively tilted upper level trough. Models have all started to
show the lower-atmospheric response to this (in addition to the
ongoing cold air advection) in the form of a surface low spinning
up in Prince William Sound. Models are not currently showing
precipitation wrapping all the way back into the Anchorage and
Mat-Su Valleys from this development, but anytime we see a
negatively tilted upper trough there is the potential for the
moisture to come back further to the west than expected. Thus have
kept moderate chances for precip in the forecast, and will need to
monitor subtle changes in future model runs in case it starts to
look like upper Cook Inlet could see another round of light
snowfall before things dry out on Tuesday.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
A weak trough will continue to produce light snow along the Alaska
and Aleutian Ranges tonight before moving off to the east on
Sunday. Otherwise, the main story will be clearing skies and
frigid temperatures into the beginning of the work week as colder
air filters into the region on the back side of the longwave
trough sitting over the western mainland.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
Convective snow showers will continue across the central and
eastern Bering through Sun night as cold northerly flow continues
over the region. Attention will turn to a powerful low approaching
the Western Aleutians late Sunday into Monday. This will push a
storm force front into the Central and Western Aleutians, with
hurricane force gusts possible over the waters of the western
Bering. The front will then shift eastward towards Dutch Harbor
and the Pribilof Islands Monday afternoon into Monday evening
accompanied by heavy precipitation and gale force winds. Blowing
snow is not expected to be a significant concern across the chain
as snow quickly changes over to rain with the arrival of the
front, however it may eventually become an issue over the
Pribilofs where cold air hangs on a little bit longer.

&&

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

The long term forecast starting Tuesday will continue the active
trend. The western weather pattern will be dominated by a cluster
of lows that will slide north across the Kamchatka peninsula.
beneath these systems and at the surface will be low pressure
systems that will slide north - pulling a warm front with it. Each
successful low will drive more moisture and warmth north,
eventually eating away at the cold h85 temperatures that will
settle in through this weekend. By Wednesday evening the first of
these lows will slip north across Norton Sound. This low will
pull a weakening front across southcentral late in the week. The
forecast confidence in specifics drops mid week for a few reasons.
All guidance agrees on a low spinning along the front that will be
driven east along the AKPEN and south of Kodiak. It is at this
point that the biggest differences, and ultimately the drivers in
our weather, appear. The GFS drives the low well south of the Gulf
of Alaska while the EC and Canadian skirt Prince William Sound.
GFS Ensemble members do not give too much help as the spread is
rather large into the early week. Wednesday the GFS and ensembles
keep SC dry while the EC and Canadian bring in some snow.
Regardless, an active pattern will continue through next weekend
with details to be appearing through the week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Storms 175-178 411 413. Gales 173 174 412.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...AD
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...CB
LONG TERM...SS