Gale Warning 172, NWS Anchorage, AK

790 
FZAK52 PAFC 160018
CWFALU

Coastal Waters Forecast
National Weather Service Anchorage Alaska
318 PM AKST Thu Feb 15 2018

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.

PKZ199-161345-
318 PM AKST Thu Feb 15 2018
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
A 965 mb low 390NM southwest of Shemya moves to 215NM west 
northwest of Shemya Fri afternoon with a pressure of 973 mb. This 
low then moves to 440NM northwest of Shemya Sat afternoon weakening
to 984 mb. A new 1008 mb around 540NM south of Nikolski moves to 
320NM northwest of St Paul Island Sat afternoon with a central 
pressure of 993 MB.

$$

PKZ150-161345-
South of the AK Peninsula Sitkinak to Castle Cape-
318 PM AKST Thu Feb 15 2018

...GALE WARNING FRIDAY...

.TONIGHT...SE wind 20 kt. Seas 9 ft. Rain.
.FRI...NW wind 35 kt. Seas 11 ft.
.FRI NIGHT...NW wind 25 kt becoming N 15 kt after midnight. 
Seas 10 ft.
.SAT...SE wind 30 kt. Seas 8 ft.
.SAT NIGHT...SE wind 30 kt. Seas 15 ft.
.SUN...SW wind 30 kt. Seas 13 ft.
.MON THROUGH TUE...SW wind 25 kt. Seas 9 ft.

$$

PKZ155-161345-
South of the AK Peninsula Castle Cape to Cape Sarichef-
318 PM AKST Thu Feb 15 2018

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...NW wind 25 kt. Seas 12 ft.
.FRI...NW wind 25 kt diminishing to 15 kt in the afternoon. Seas
13 ft.
.FRI NIGHT...E wind 20 kt increasing to 30 kt after midnight. From
the Shumagin Islands E, variable wind 10 kt becoming E 20 kt after
midnight. Seas 10 ft.
.SAT...SE wind 40 kt. Seas 20 ft.
.SAT NIGHT...S wind 35 kt. Seas 19 ft.
.SUN THROUGH TUE...SW wind 25 kt. Seas 12 ft.

$$

PKZ160-161345-
Bristol Bay-
318 PM AKST Thu Feb 15 2018

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TONIGHT...SE wind 25 kt becoming SW after midnight. Seas in ice
free waters 5 ft. Snow and widespread rain showers.
.FRI...NW wind 30 kt diminishing to 20 kt in the afternoon. Seas
in ice free waters 7 ft.
.FRI NIGHT...N wind 10 kt becoming E after midnight. Seas in ice
free waters 5 ft.
.SAT...E wind 30 kt. Seas in ice free waters 6 ft.
.SAT NIGHT...SE wind 35 kt. Seas in ice free waters 8 ft.
.SUN...SW wind 30 kt. Seas in ice free waters 5 ft.
.MON THROUGH TUE...S wind 20 kt. Seas in ice free waters 6 ft.

$$

PKZ165-161345-
Port Heiden to Cape Sarichef-
318 PM AKST Thu Feb 15 2018

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 7 ft building to 11 ft after
midnight.
.FRI...S wind 20 kt. From Port Moller E, NW wind 20 kt in the
morning becoming variable 10 kt. Seas 12 ft.
.FRI NIGHT...E wind 25 kt. Seas 8 ft.
.SAT...SE wind 40 kt. Seas 11 ft.
.SAT NIGHT...S wind 35 kt. Seas 11 ft.
.SUN THROUGH TUE...S wind 25 kt. Seas 8 ft.

$$

PKZ170-161345-
Cape Sarichef to Nikolski Bering Side-
318 PM AKST Thu Feb 15 2018

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...W wind 25 kt. Seas 16 ft.
.FRI...S wind 30 kt. Seas 14 ft.
.FRI NIGHT...SE wind 30 kt. Seas 10 ft.
.SAT...SE wind 40 kt. Seas 16 ft.
.SAT NIGHT...SW wind 20 kt. Seas 9 ft.
.SUN THROUGH MON...S wind 30 kt. Seas 9 ft.
.TUE...S wind 25 kt. Seas 9 ft.

$$

PKZ171-161345-
Unalaska Bay-
318 PM AKST Thu Feb 15 2018

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

.TONIGHT...W wind 25 kt becoming SW 15 kt after midnight. 
Seas 3 ft.
.FRI...S wind 20 kt. Seas 3 ft.
.FRI NIGHT...SE wind 30 kt. Seas 3 ft building to 5 ft 
after midnight. Rain.
.SAT...SE wind 40 kt. Seas 5 ft.
.SAT NIGHT...SW wind 15 kt. Seas 2 ft.
.SUN THROUGH MON...S wind 25 kt. Seas 3 ft.
.TUE...S wind 20 kt. Seas 2 ft.

$$

PKZ172-161345-
Cape Sarichef to Nikolski Pacific Side-
318 PM AKST Thu Feb 15 2018

...GALE WARNING FRIDAY NIGHT...

.TONIGHT...W wind 25 kt diminishing to 15 kt after midnight. 
Seas 16 ft.
.FRI...SE wind 25 kt. Seas 12 ft.
.FRI NIGHT...SE wind 25 kt becoming E 35 kt after midnight. 
Seas 10 ft building to 19 ft after midnight. Rain.
.SAT...SE wind 45 kt. Seas 23 ft.
.SAT NIGHT...SW wind 15 kt. Seas 16 ft.
.SUN...S wind 35 kt. Seas 12 ft.
.MON...S wind 30 kt. Seas 14 ft.
.TUE...S wind 25 kt. Seas 14 ft.

$$

PKZ173-161345-
Nikloski to Seguam Island Bering Side-
318 PM AKST Thu Feb 15 2018

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...SW wind 25 kt becoming S 35 kt after midnight. 
Seas 18 ft.
.FRI...S wind 40 kt. Seas 15 ft.
.FRI NIGHT...SE wind 35 kt. Seas 14 ft. Snow.
.SAT...S wind 20 kt. Seas 10 ft.
.SAT NIGHT...SW wind 20 kt. Seas 9 ft.
.SUN...S wind 45 kt. Seas 11 ft.
.MON...S wind 30 kt. Seas 13 ft.
.TUE...SW wind 20 kt. Seas 11 ft.

$$

PKZ174-161345-
Nikolski to Seguam Island Pacific Side-
318 PM AKST Thu Feb 15 2018

...GALE WARNING FRIDAY...

.TONIGHT...SW wind 20 kt becoming S 30 kt after midnight. 
Seas 18 ft.
.FRI...S wind 35 kt. Seas 16 ft.
.FRI NIGHT...SE wind 30 kt. Seas 18 ft. Snow.
.SAT AND SAT NIGHT...SW wind 15 kt. Seas 18 ft.
.SUN...S wind 45 kt. Seas 15 ft.
.MON...S wind 30 kt. Seas 16 ft.
.TUE...S wind 20 kt. Seas 16 ft.

$$

PKZ175-161345-
Seguam Island to Adak Bering Side-
318 PM AKST Thu Feb 15 2018

...STORM WARNING FRIDAY...

.TONIGHT...S wind 30 kt increasing to 45 kt after midnight. 
Seas 16 ft.
.FRI...S wind 50 kt. Seas 19 ft.
.FRI NIGHT...S wind 35 kt becoming SE 25 kt after midnight. 
Seas 16 ft. Rain and snow.
.SAT...SW wind 15 kt. Seas 10 ft.
.SAT NIGHT...SW wind 20 kt. Seas 9 ft.
.SUN...S wind 40 kt. Seas 14 ft.
.MON...S wind 30 kt. Seas 11 ft.
.TUE...SW wind 20 kt. Seas 8 ft.

$$

PKZ176-161345-
Seguam Island to Adak Pacific Side-
318 PM AKST Thu Feb 15 2018

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...S wind 35 kt increasing to 45 kt after midnight. 
Seas 19 ft.
.FRI...S wind 45 kt. Seas 26 ft.
.FRI NIGHT...S wind 35 kt becoming SE 25 kt after midnight. 
Seas 25 ft.
.SAT AND SAT NIGHT...SW wind 20 kt. Seas 16 ft.
.SUN...S wind 45 kt. Seas 19 ft.
.MON...S wind 30 kt. Seas 16 ft.
.TUE...SW wind 20 kt. Seas 16 ft.

$$

PKZ177-161345-
Adak to Kiska-
318 PM AKST Thu Feb 15 2018

...STORM WARNING THROUGH FRIDAY...

.TONIGHT...S wind 50 kt. Seas 19 ft building to 25 ft after
midnight. Widespread rain and snow showers.
.FRI...S wind 50 kt diminishing to 40 kt in the afternoon. 
Seas 25 ft Bering side...29 ft Pacific side. Rain.
.FRI NIGHT...S wind 30 kt. Seas 19 ft Bering side... 26 ft 
Pacific side. Rain.
.SAT...SW wind 20 kt. Seas 19 ft.
.SAT NIGHT...SW wind 20 kt. Seas 14 ft.
.SUN...SE wind 35 kt. Seas 18 ft.
.MON...S wind 30 kt. Seas 16 ft.
.TUE...SW wind 20 kt. Seas 18 ft.

$$

PKZ178-161345-
Kiska to Attu-
318 PM AKST Thu Feb 15 2018

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...S wind 45 kt. Bering side, seas 18 ft. Pacific side,
seas 20 ft building to 28 ft after midnight. Widespread snow 
showers.
.FRI...S wind 40 kt. Seas 29 ft. Rain showers.
.FRI NIGHT...S wind 40 kt. Seas 28 ft.  and rain showers.
.SAT...SW wind 30 kt. Seas 19 ft.
.SAT NIGHT...S wind 25 kt. Seas 13 ft.
.SUN...E wind 30 kt. Seas 20 ft.
.MON...W wind 20 kt. Seas 20 ft.
.TUE...SW wind 15 kt. Seas 16 ft.

$$

PKZ179-161345-
Pribilof Islands Near Shore Waters-
318 PM AKST Thu Feb 15 2018

...GALE WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...SW wind 30 kt. Seas 20 ft.
.FRI...S wind 40 kt. Seas 19 ft.
.FRI NIGHT...S wind 35 kt. Seas 19 ft.
.SAT...SE wind 35 kt. Seas 19 ft.
.SAT NIGHT...SW wind 20 kt. Seas 14 ft.
.SUN THROUGH MON...S wind 30 kt. Seas 12 ft.
.TUE...SW wind 20 kt. Seas 12 ft.

$$

PKZ180-161345-
Kuskokwim Delta and Etolin Strait-
318 PM AKST Thu Feb 15 2018

...SMALL CRAFT ADVISORY THROUGH FRIDAY NIGHT...

.TONIGHT...S wind 30 kt becoming SW 20 kt after midnight. 
Seas 9 ft. Snow.
.FRI...SW wind 20 kt becoming S 30 kt in the afternoon. 
Seas 9 ft. Patchy freezing fog.
.FRI NIGHT...S wind 30 kt. Seas 8 ft. Freezing spray.
.SAT AND SAT NIGHT...SE wind 40 kt. Seas 14 ft.
.SUN THROUGH MON...S wind 25 kt. Seas 7 ft.
.TUE...SW wind 20 kt. Seas 7 ft.

$$

PKZ181-161345-
North and West of Nunivak Island-
318 PM AKST Thu Feb 15 2018

...GALE WARNING TONIGHT...

.TONIGHT...S wind 35 kt diminishing to 25 kt after midnight. 
Seas in ice free waters 10 ft. Freezing spray.
.FRI...S wind 30 kt. Seas in ice free waters 10 ft. Patchy
freezing fog.
.FRI NIGHT...S wind 30 kt. Seas in ice free waters 10 ft. 
Freezing spray.
.SAT AND SAT NIGHT...SE wind 40 kt. Seas in ice free waters 12 ft.
.SUN THROUGH TUE...SW wind 25 kt. Seas in ice free waters 6 ft.

$$

PKZ185-161345-
Saint Matthew Island Waters-
318 PM AKST Thu Feb 15 2018

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...S wind 40 kt. Seas 24 ft. Rain showers.
.FRI...S wind 30 kt increasing to 40 kt in the afternoon. 
Seas 20 ft. Widespread snow and rain showers.
.FRI NIGHT...S wind 40 kt diminishing to 30 kt after midnight.
Seas 22 ft.
.SAT...SE wind 35 kt. Seas 20 ft.
.SAT NIGHT...S wind 35 kt. Seas 17 ft.
.SUN THROUGH MON...S wind 30 kt. Seas 14 ft.
.TUE...SW wind 20 kt. Seas 12 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
456 PM AKST Wed Feb 14 2018

.ANALYSIS AND UPPER LEVELS...
The 500 mb ridge has moved eastward to near the Alcan border with
a trough over Southwest Alaska providing enough lifting in
southwest flow for widespread light precipitation. This trough
continues to progress eastward and will move over Southcentral to
the Copper River Basin overnight. The next upper level ridge is
amplifying in the eastern Bering Sea today and will move over
Southcentral by tomorrow afternoon. A deep upper level low remains
anchored near the Kamchatka Peninsula, allowing the ridge to
amplify over the Bering Sea to its east. The surface gradient
along the north Gulf coast has diminished, bringing outflow winds
to an end. However, winds will increase again tomorrow with the
building ridge.

&&

.MODEL DISCUSSION...
For the second day in a row the 12Z and 18Z model runs have
brought a much better semblance of consensus on the low tracks
and the expected central pressures. This is the case for both the
Gulf of Alaska and Bering Sea regions into the weekend. Models all
remain consistent with the surface ridge moving over the mainland
part of the state early in the weekend and edging eastward to the
Alcan border by the end of the weekend.

&&

.AVIATION...
PANC...Periods of snow will affect the airport this afternoon and
evening, lowering to MVFR conditions and perhaps briefly down to
IFR. Ceilings and vis should improve quite a bit in between bands
of snow. Mid and upper levels will rapidly dry out behind the
upper trough axis after midnight, so it looks favorable for
stratus and fog to develop, with IFR or even low IFR conditions
possible between 12z and 18z. Forecast is conservative
(optimistic) for now, but will re-evaluate fog potential as this
system evolves this evening.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A shortwave is pushing through Southcentral Alaska from the west
which is bringing snow to the area that will track east through
Thursday morning. The wave looks to move through relatively
quickly which will help keep total snow amounts low. Behind the
shortwave, high pressure will build in from the west which will
clear out the snow and cloud cover Thursday. Thursday night into
Friday another system will approach the area from the southwest
bringing rain and snow to Kodiak Island. However, with the low
tracking east through the southern Gulf, little precip will make
it further north to the rest of Southcentral Alaska.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
(Tonight through Friday)
The weak surface front which brought light snow to much of
Southwest Alaska is about to exit the region, as it's currently
aligned with the Alaska Range. Much drier air with clearing skies
will overspread the region overnight, allowing temperatures to
plummet, with most locations being about 10 to 15 degrees cooler
than last night. The departing front will also allow for a
decreased pressure gradient. With partly cloudy skies and low
level moisture remaining from the recent snowfall this will
provide a good radiational cooling setup. Thus, look for areas
of fog to develop this evening into the overnight hours while
expanding in coverage.

Our attention then turns to another approaching front for Thursday,
with the latest model guidance showing a coastal arrival in the
mid afternoon time frame, continuing eastward while weakening
some for Friday. Widespread precipitation will once again
accompany this front, most of which will be in the form of snow.
However, frontal speed will temporally limit any snowfall
accumulation potential, with just light amounts expected.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
(Tonight through Friday)
Clearing skies have overspread much of the eastern Bering through
the AKpen, with light winds in place as well. Was tempted to add
patchy fog to the forecast for the Peninsula. However, winds
should become southeasterly overnight while increasing in speed
some compared to the Mainland, with mixing helping mitigate this
potential. Otherwise, look for a storm force low to continue
moving northward through the western Bering, sending a front
eastward through he chain. Strong gusty winds and increasing
precipitation coverage/intensity will precede this front as it
continues its eastward trek, with more showery precipitation
behind it and winds dropping off to gales the further away from
the low one travels.

&&

.LONG TERM FORECAST (Days 3 through 7)...
As a decaying front across the Anchorage area slides East on
Friday afternoon, only a slight decrease to temperatures and
increase of clouds are to be expected. Temperatures aloft will
cool through that time but begin to rebound into the weekend and
beyond. Skies are expected to clear out by the early weekend. Now
that we are back into the season of the sun helping to aid in
warmth, daytime temperatures will quickly rise. Diurnal swings of
20 degrees, or more, are not out of the question. Interior and
river valley areas of the Copper River Basin should see night
temperatures drop well below zero as any warmth radiates out
overnight. Clouds will increase Sunday afternoon with an
approaching front from the west. However, guidance has a harder
time figuring out how far the front will move to the east. If it
has enough oomph to overtake the ridging over the area, we may see
snow Monday afternoon into the evening hours. The GFS is showing
the strongest of these signals. The EC is indicating a much weaker
front with light snow, and the Canadian is showing nothing.
Regardless, the nature of ridging and troughing will continue
progressively through this weekend and into next.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Heavy Freezing Spray Warning 181.
         Storm Warning 177.
         Gale Warning 173 174 175 176 178 179 180 181 185.

&&

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