Gale Warning 169, NWS Anchorage, AK

563 
FZAK51 PAFC 132341
CWFAER

Coastal Waters Forecast
National Weather Service Anchorage Alaska
241 PM AKST Tue Feb 13 2018

Coastal Waters Forecast for the Northern Gulf of Alaska Coast
up to 100 nm out including Kodiak Island and Cook Inlet.

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.

PKZ197-141230-
241 PM AKST Tue Feb 13 2018
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...

High pressure will be over the Gulf through Wed night. On Thu a 
front associated with a low in the Bering Sea will bring easterly 
winds to coastal areas south of Chiniak.

$$

PKZ119-141230-
Cape Suckling to Cape Cleare-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 25 kt diminishing to 15 kt after midnight. Seas
11 ft.
.WED...SW wind 15 kt. Seas 7 ft.
.WED NIGHT...W wind 15 kt. Seas 6 ft.
.THU AND THU NIGHT...Variable wind 10 kt. Seas 4 ft.
.FRI...NE wind 20 kt. Seas 6 ft.
.SAT...NW wind 15 kt. Seas 6 ft.
.SUN...Variable wind 10 kt. Seas 5 ft.

$$

PKZ120-141230-
Cape Cleare to Gore Point-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY TONIGHT...

.TONIGHT...NW wind 30 kt. Seas 10 ft.
.WED...W wind 20 kt. Seas 6 ft.
.WED NIGHT...W wind 15 kt. Seas 6 ft.
.THU...Variable wind 10 kt. Seas 4 ft.
.THU NIGHT...Variable wind 10 kt. Seas 3 ft.
.FRI...N wind 20 kt. Seas 6 ft.
.SAT...NW wind 20 kt. Seas 6 ft.
.SUN...Variable wind 10 kt. Seas 5 ft.

$$

PKZ121-141230-
Resurrection Bay-
241 PM AKST Tue Feb 13 2018

.TONIGHT...N wind 20 kt diminishing to 10 kt after midnight. Seas 4 
ft subsiding to 2 ft after midnight.
.WED...N wind 10 kt. Seas 2 ft.
.WED NIGHT...N wind 10 kt increasing to 15 kt after midnight. Seas
3 ft. Freezing spray.
.THU AND THU NIGHT...N wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...N wind 20 kt. Seas 4 ft.
.SUN...N wind 15 kt. Seas 3 ft.

$$

PKZ125-141230-
Prince William Sound-
241 PM AKST Tue Feb 13 2018

.TONIGHT...NW wind 20 kt becoming N 10 kt after midnight. Seas 4 ft
subsiding to 2 ft after midnight.
.WED...Variable wind less than 10 kt becoming NE 10 kt in the
afternoon. Seas 2 ft.
.WED NIGHT...N wind 10 kt. Seas 2 ft.
.THU...N wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI THROUGH SUN...NE wind 10 kt. Seas 2 ft.

$$

PKZ126-141230-
Port Valdez-
241 PM AKST Tue Feb 13 2018

.TONIGHT...NE wind 10 kt. Seas 2 ft.
.WED...E wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU...NE wind 10 kt. Seas 2 ft.
.THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 3 ft.
.SUN...NE wind 10 kt. Seas 2 ft.

$$

PKZ127-141230-
Valdez Narrows-
241 PM AKST Tue Feb 13 2018

.TONIGHT...NE wind 20 kt. Seas 3 ft.
.WED...NE wind 15 kt. Seas 3 ft.
.WED NIGHT...NE wind 15 kt. Seas 3 ft.
.THU...NE wind 20 kt. Seas 3 ft.
.THU NIGHT...NE wind 25 kt. Seas 3 ft.
.FRI...NE wind 25 kt. Seas 3 ft.
.SAT...NE wind 20 kt. Seas 3 ft.
.SUN...NE wind 15 kt. Seas 3 ft.

$$

PKZ128-141230-
Valdez Arm-
241 PM AKST Tue Feb 13 2018

.TONIGHT...N wind 15 kt. Seas 3 ft.
.WED...NE wind 10 kt. Seas 2 ft.
.WED NIGHT...NE wind 10 kt. Seas 2 ft.
.THU AND THU NIGHT...NE wind 15 kt. Seas 3 ft.
.FRI THROUGH SAT...NE wind 15 kt. Seas 3 ft.
.SUN...NE wind 10 kt. Seas 2 ft.

$$

PKZ129-141230-
Passage Canal-
241 PM AKST Tue Feb 13 2018

.TONIGHT...W wind 20 kt. Seas 3 ft.
.WED...W wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt becoming W 10 kt after
midnight. Seas 2 ft.
.THU AND THU NIGHT...W wind 10 kt. Seas 2 ft.
.FRI THROUGH SAT...W wind 15 kt. Seas 2 ft.
.SUN...E wind 15 kt. Seas 2 ft.

$$

PKZ130-141230-
West of Barren Islands including Kamishak Bay-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TONIGHT...W wind 25 kt. Seas 6 ft.
.WED...SW wind 25 kt in the morning becoming variable 10 kt. Seas 6 
ft.
.WED NIGHT...N wind 15 kt. Seas 3 ft.
.THU...NE wind 25 kt. Seas 5 ft.
.THU NIGHT...E wind 20 kt. Seas 5 ft.
.FRI...NW wind 25 kt. Seas 5 ft.
.SAT...NW wind 15 kt. Seas 3 ft.
.SUN...Variable wind 10 kt. Seas 3 ft.

$$

PKZ131-141230-
Barren Islands East-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY TONIGHT...

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

$$

PKZ132-141230-
Marmot Island to Sitkinak-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TONIGHT...W wind 25 kt. Seas 9 ft.
.WED...SW wind 25 kt. Seas 7 ft.
.WED NIGHT...SW wind 15 kt in the evening becoming variable 10 kt.
Seas 6 ft.
.THU...E wind 20 kt. Seas 6 ft.
.THU NIGHT...SE wind 20 kt. Seas 7 ft.
.FRI...NW wind 30 kt. Seas 9 ft.
.SAT...W wind 20 kt. Seas 8 ft.
.SUN...S wind 15 kt. Seas 7 ft.

$$

PKZ136-141230-
Chiniak Bay-
241 PM AKST Tue Feb 13 2018

.TONIGHT...W wind 10 kt. Seas 2 ft.
.WED...SW wind 15 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU...Variable wind less than 10 kt. Seas 3 ft.
.THU NIGHT...SE wind 15 kt. Seas 3 ft.
.FRI...NW wind 20 kt. Seas 3 ft.
.SAT...W wind 10 kt. Seas 2 ft.
.SUN...S wind 10 kt. Seas 1 ft.

$$

PKZ137-141230-
Marmot Bay-
241 PM AKST Tue Feb 13 2018

.TONIGHT...W wind 15 kt becoming SW 10 kt after midnight. Seas 3
ft.
.WED...SW wind 10 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt. Seas 2 ft.
.THU...Variable wind less than 10 kt. Seas 3 ft.
.THU NIGHT...SE wind 10 kt. Seas 3 ft.
.FRI...W wind 20 kt. Seas 3 ft.
.SAT...W wind 10 kt. Seas 2 ft.
.SUN...SE wind 10 kt. Seas 3 ft.

$$

PKZ138-141230-
Shelikof Strait-
241 PM AKST Tue Feb 13 2018

...SMALL CRAFT ADVISORY THROUGH WEDNESDAY...

.TONIGHT...SW wind 25 kt. Seas 7 ft.
.WED...SW wind 25 kt. Seas 7 ft.
.WED NIGHT...Variable wind 10 kt. Seas 2 ft.
.THU AND THU NIGHT...E wind 15 kt. Seas 3 ft.
.FRI...W wind 20 kt. Seas 4 ft.
.SAT...SW wind 15 kt. Seas 3 ft.
.SUN...Variable wind 10 kt. Seas 2 ft.

$$

PKZ139-141230-
Cook Inlet Kalgin Island to Point Bede-
241 PM AKST Tue Feb 13 2018

.TONIGHT...W wind 15 kt in the evening becoming variable less than 
10 kt. Seas in ice free waters 3 ft.
.WED...NE wind 15 kt. Seas in ice free waters 3 ft.
.WED NIGHT...Variable wind less than 10 kt becoming N 15 kt after
midnight. Seas in ice free waters 1 ft building to 3 ft after
midnight.
.THU AND THU NIGHT...NE wind 20 kt. Seas in ice free waters 5 ft.
.FRI...N wind 15 kt. Seas in ice free waters 3 ft.
.SAT THROUGH SUN...NE wind 10 kt. Seas in ice free waters 2 ft.

$$

PKZ140-141230-
Cook Inlet North of Kalgin Island-
241 PM AKST Tue Feb 13 2018

.TONIGHT...Variable wind less than 10 kt.
.WED...NE wind 10 kt.
.WED NIGHT...Variable wind less than 10 kt.
.THU...N wind 10 kt.
.THU NIGHT...Variable wind less than 10 kt.
.FRI THROUGH SUN...NE wind 10 kt.

$$

PKZ141-141230-
Kachemak Bay-
241 PM AKST Tue Feb 13 2018

.TONIGHT...SW wind 15 kt in the evening becoming variable less
than 10 kt. Seas 4 ft subsiding to 2 ft tonight.
.WED...SE wind 10 kt in the morning becoming variable less than
10 kt. Seas 2 ft.
.WED NIGHT...Variable wind less than 10 kt becoming NE 10 kt after
midnight. Seas 2 ft.
.THU AND THU NIGHT...NE wind 10 kt. Seas 2 ft.
.FRI...NW wind 15 kt. Seas 2 ft.
.SAT...NW wind 10 kt. Seas 2 ft.
.SUN...E wind 10 kt. Seas 2 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
405 PM AKST Mon Feb 12 2018

.ANALYSIS AND UPPER LEVELS...
The warm upper level ridge has drifted over Southeast Alaska which
brought the jet stream over Prince William Sound this morning and
it is slowly moving eastward. The upper level trough is over
Southwest mainland Alaska and tracking eastward in progressive
upper level flow as a low amplitude ridge is over the central
Bering Sea. This ridge is expected to amplify as it heads eastward
tomorrow.
At the surface there is a weak low in northern Cook Inlet which
has been the catalyst for downslope winds today over the Anchorage
area. This low should move eastward into Prince William Sound
this evening and move quickly eastward. This change in low
location will also start gusty outflow winds over the north Gulf
Coast.

&&

.MODEL DISCUSSION...
While models remain in good overall synoptic agreement until
late in the week, there are enough uncertainties to keep a degree
of uncertainty to the forecasts. The biggest questions arise in
the Bering Sea for middle to late in the week as there is
significant differences in the track of two different lows. Models
all recognize the lows but tracks remain hundreds of miles apart.
The short term challenges concentrate on winds in Turnagain Arm
and the upper Cook Inlet region this evening and the way the
pattern transitions to gusty northerly winds along the Gulf coast
tomorrow. Higher resolution models, especially the NAMnest, are
performing best with this effort.

&&

.AVIATION...
PANC...Southeast winds and the warming they bring with the
downslope effect has been the story for PANC today. These winds
should diminish late this afternoon and become more southerly.
When this happens it should allow a period of snow to move into
the area and lower ceilings and visibilities. The issue is whether
there is any precipitation still moving through by the time this
occurs. There is also the chance of fog to develop early tomorrow
morning. While there may be enough residual cloud cover to keep it
from developing, the warmer and wet conditions certainly increase
the chance of fog.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
As has been the case since yesterday, the primary forecast
challenge this evening will be with Southcentral precip type as
the southeasterly winds diminish, which should allow for
temperatures aloft to begin to fall cold enough to support snow.
The challenge lies in determining how quickly this occurs, which
none of the models have been capturing this very well by
diminishing the winds and switching over to snow too quickly. At
this point we expect a rain/snow mix to continue over much of the
area until the early evening when the winds aloft should die off
enough to bring accumulating snow to the surface. Since this is
much slower than initially expected (snow was initially expected
to start by this afternoon), accumulation up to 2 inches expected.
With this being such a complex forecast challenge, confidence in
the exact timing of the snow transition and accumulations is low,
though there is reasonable confidence that at least some snow
should fall before the upper trough axis passes over late this
evening. Further north over the Susitna Valley the Winter Weather
Advisory continues until 9 pm this evening, though the remaining
snowfall will be noticeably higher than what fell last night and
this morning.

The general trend for the entire area will be for improving
conditions from west-east after midnight as the upper trough axis
passes overhead. This should allow for clearing skies and
temperatures falling back below freezing for the Anchorage Metro,
while further east into the Copper River Basin and Valdez/Thompson
Pass areas will see an additional few inches of snowfall until
Tuesday morning. Beginning Tuesday morning as the surface low
moves into the Eastern Gulf, gap winds will increase throughout
the North Gulf Coast, along with strong winds and blowing snow
through Thompson Pass. Since reports from Thompson Pass from this
storm so far have been relatively light (around 6"), the blowing
snow is not expected to cause a significant reduction to
visibilities, and should quickly diminish as the pressure gradient
diminishes Tuesday evening. Wednesday then looks like a generally
quiet day for much of the area as a brief ridge of high pressure
moves in, with no precipitation expected until shortwave brings a
chance of light snow back into the Susitna Valley for the evening.

&&

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

The last of the snow showers across Southwest Alaska are ending
and becoming confined to the western slopes of the Kuskokwim and
Alaska Ranges this evening. A brief break in the precipitation is
expected overnight into Tuesday morning through Bristol Bay and
the Lower Kuskokwim Valley. Meanwhile for the Kuskokwim Delta
precipitation associated with the next front will already be
making its way into the area before sunrise Tuesday. Any warm air
associated with the front will have long occluded out, so the
dominant precipitation type with the front will be snow,
especially early in the morning.

On Tuesday, rising temperatures through the day may cause the
snow to mix with or occasionally change over to rain during the
afternoon. Regardless, above freezing surface temperatures for
much of the day will diminish the threat for much accumulation. At
times however, the snow may be heavy enough to produce light
accumulations in the morning. For the rest of Southwest Alaska,
the slowing eastward movement of the front means that
precipitation will take a long time spreading into Bristol Bay.
In fact, outside of the occasional rain or snow shower, points
from Dillingham eastward are not expected to get very much
precipitation at all on Tuesday.

The stalled front will continue precipitation throughout the
Kuskokwim Valley, Delta, and west of Dillingham overnight Tuesday
night. Gradually cooling air should turn most areas back over to
all snow Tuesday evening, with additional accumulations on the
order of 1-3 inches expected overnight in the aforementioned
areas. The front will steadily weaken overnight, so snowfall rates
should diminish with time. A few lingering snow showers will
continue into the day Wednesday, particularly along the Kuskokwim
Mountains and the lower Kuskokwim Valley. Some clearing is
possible by Wednesday evening, particularly the further south and
west you are.

&&

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

The primary hazardous weather across the Bering and Aleutians is
expected overnight tonight in association with a strong front
moving eastward across the Aleutians. As the front moves into the
central Aleutians overnight, additional upper level energy will
translate into developing storm force winds in addition to light
to moderate rain. Adak, Atka, and the surrounding areas will all
be impacted by the storm force winds with gusts of 60-70 mph. The
front will rapidly weaken as it moves into the eastern Bering and
Aleutians on Tuesday, though gusts exceeding 50 mph with 20-30
foot seas will still be common. Colder air moving in behind the
front through the western and northern Bering Tuesday will result
in scattered to numerous snow showers developing across that
region with small craft advisory winds and seas common. The
stalled front over the eastern Bering will persist through Tuesday
night, with ongoing widespread showers continuing over much of
the rest of the Bering.

On Wednesday, a new low will develop south of the western and
central Aleutians and move into that part of the chain during the
day, with a rain/snow mix expected in association with it. Winds
ahead of the low look to be only in the 25-35 kt range, though
stronger gales will move into the area behind the low Wednesday
night.

&&

.LONG TERM FORECAST (Days 3 through 7)...
A weak trough will cross Southcentral Alaska Wednesday night. A
ridge will build behind this trough, over southwest Alaska on
Wednesday night and then into Southcentral on Thursday. An upper
low over the central Aleutians Wednesday night will move quickly
into the central Bering by Thursday afternoon. This low will then
push into southwest Alaska on Friday, weakening and then racing
across the Gulf. A large ridge will then build over mainland
Alaska late Friday, keeping the area protected from any weather
systems through Saturday. Another Bering system will push into
southwest Alaska on Sunday, and then weaken and/or dissipate as it
moves across Southcentral Sunday night into the fairly strong
ridge. By this time the models differ on the timing and details of
this system and various systems over the Bering and Aleutians.
They do, however, agree fairly well on the over-all synoptic
situation for early next week with a ridge over the northeast
Pacific and most of the mainland, and a deep trough over the
Bering Sea and Aleutians.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 145.
MARINE...Storm 130 131 173 175 176 177 178.
         Gale 120 121 125 132 138 165 170 172 174 179
              180 181 185.

&&

SYNOPSIS AND MODEL DISCUSSION...EZ
SOUTHCENTRAL ALASKA...DEK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...JW
LONG TERM...BL