Gale Warning 670, NWS Anchorage, AK

931 
FZAK61 PAFC 050021
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
321 PM AKST Mon Dec 4 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-051345-
321 PM AKST Mon Dec 4 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 996 mb low over the northeast Pacific Tue afternoon will move 
to 53N 148W at 993 mb by Tue night and then to 59N 150W at 990 nm 
by Wed afternoon.

$$

PKZ351-051345-
Gulf of Alaska Offshore North of 57N and West of 144W-
321 PM AKST Mon Dec 4 2017

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...SE wind 20 to 30 kt. Seas 13 to 21 ft. Rain.
.TUE...SE wind 15 to 30 kt. Seas 8 to 13 ft.
.TUE NIGHT...SE wind 25 to 40 kt. Seas 11 to 19 ft. Rain.
.WED...SE wind 20 to 35 kt. Seas 13 to 21 ft.
.WED NIGHT...S wind 10 to 25 kt. Seas 14 to 20 ft.
.THU THROUGH SAT...SE wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ352-051345-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
321 PM AKST Mon Dec 4 2017

...GALE WARNING TUESDAY NIGHT...

.TONIGHT...S wind 20 to 30 kt becoming SE 10 to 25 kt after
midnight. Seas 11 to 19 ft.
.TUE...SE wind up to 15 kt increasing to 15 to 30 kt in the
afternoon. Seas 10 ft building to 8 to 16 ft in the afternoon.
.TUE NIGHT...E wind 25 to 40 kt. Seas 11 to 19 ft. Rain.
.WED...SE wind 20 to 35 kt. Seas 12 to 20 ft.
.WED NIGHT...SE wind 10 to 25 kt. Seas 12 to 18 ft.
.THU THROUGH SAT...SE wind 15 to 30 kt. Seas 10 to 18 ft.

$$

922 
FZAK61 PAFC 051251
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
351 AM AKST Tue Dec 5 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-060145-
351 AM AKST Tue Dec 5 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 1003 mb low at 55N 145W moves to 59N 147W at 1004 mb Tue afternoon
and then moves inland. Another 996 mb low at 52N 148W Tue night 
moves to 59N 149W at 995 mb Wed afternoon and then moves inland Wed 
night. A strong front remains nearly stationary in the eastern Gulf 
throughout the forecast period.

$$

PKZ351-060145-
Gulf of Alaska Offshore North of 57N and West of 144W-
351 AM AKST Tue Dec 5 2017

...GALE WARNING TONIGHT AND WEDNESDAY...

.TODAY...S wind 15 to 30 kt. Seas 9 to 14 ft.
.TONIGHT...E wind 20 to 35 kt. Seas 11 to 19 ft. Rain.
.WED...SE wind 25 to 40 kt. Seas 14 to 22 ft. Rain.
.WED NIGHT...SE wind 15 to 30 kt. Seas 14 to 20 ft.
.THU THROUGH SAT...SE wind 15 to 30 kt. Seas 10 to 18 ft.

$$

PKZ352-060145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
351 AM AKST Tue Dec 5 2017

...GALE WARNING TONIGHT AND WEDNESDAY...

.TODAY...S wind 10 to 25 kt becoming 15 kt in the afternoon. Seas
8 to 16 ft.
.TONIGHT...NE wind 25 to 40 kt. Seas 11 to 19 ft. Rain.
.WED...E wind 20 to 35 kt becoming W 15 to 30 kt in the afternoon.
Seas 13 to 21 ft.
.WED NIGHT...SE wind 10 to 25 kt. Seas 12 to 18 ft.
.THU THROUGH FRI...SE wind 15 to 30 kt. Seas 9 to 17 ft.
.SAT...SE wind 15 to 25 kt. Seas 14 to 18 ft.

$$

632 
FZAK61 PAFC 060027
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
327 PM AKST Tue Dec 5 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-061330-
327 PM AKST Tue Dec 5 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 999 mb low in the North Pacific Wed afternoon moves to 60N 146W 
at 1001 mb and then moves inland Thu afternoon. A strong front 
remains nearly stationary in the eastern Gulf through Thu afternoon.

$$

PKZ351-061330-
Gulf of Alaska Offshore North of 57N and West of 144W-
327 PM AKST Tue Dec 5 2017

...GALE WARNING THROUGH WEDNESDAY...

.TONIGHT...S wind 15 to 30 kt becoming E 20 to 35 kt after
midnight. West of 146 W...Variable wind less than 10 kt. 
Seas 10 to 13 ft building to 11 to 19 ft after midnight. Rain.
.WED...SE wind 20 to 35 kt. West of 146 W...NE wind 15 kt. 
Seas 12 to 20 ft. Rain.
.WED NIGHT...SE wind up to 15 kt increasing to 20 kt after
midnight. Seas 11 to 17 ft.
.THU...SE wind 10 to 25 kt. Seas 11 to 14 ft.
.THU NIGHT...SE wind 15 to 30 kt. Seas 10 to 18 ft.
.FRI THROUGH SUN...SE wind 15 to 30 kt. Seas 11 to 18 ft.

$$

PKZ352-061330-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
327 PM AKST Tue Dec 5 2017

...GALE WARNING TONIGHT...

.TONIGHT...NE wind 20 to 35 kt. West of 146 W...NE wind 10 kt. 
Seas 10 to 18 ft. Rain.
.WED...SE wind 20 to 30 kt. West of 146 W...NE wind 15 kt. 
Seas 11 to 19 ft.
.WED NIGHT...E wind 10 to 25 kt becoming SE after midnight. 
Seas 11 to 18 ft.
.THU...SE wind 10 to 25 kt. Seas 10 to 14 ft.
.THU NIGHT...SE wind 15 to 30 kt. Seas 9 to 14 ft.
.FRI THROUGH SUN...SE wind 15 to 30 kt. Seas 10 to 18 ft.

$$

575 
FZAK61 PAFC 061218
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
318 AM AKST Wed Dec 6 2017

Offshore waters forecast for the Gulf of Alaska West of 144W

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.

PKZ399-070145-
318 AM AKST Wed Dec 6 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 988 mb North Pacific low moves to 55N 155W tonight at 986 mb. 
The low then moves inland Thu afternoon. A 982 mb low at 49N 168W 
Wed night moves to 49N 159W Thu night at 980 mb. A strong front 
remains nearly stationary in the eastern Gulf through Thu 
night.

$$

PKZ351-070145-
Gulf of Alaska Offshore North of 57N and West of 144W-
318 AM AKST Wed Dec 6 2017

...GALE WARNING THURSDAY...

.TODAY...NE wind 15 to 30 kt. Seas 12 to 20 ft. Rain.
.TONIGHT...SE wind 10 to 25 kt. Seas 13 to 17 ft.
.THU...SE wind 15 to 25 kt increasing to 20 to 35 kt in the
afternoon. Seas 12 to 16 ft. Rain.
.THU NIGHT...S wind 15 to 30 kt. Seas 11 to 18 ft.
.FRI THROUGH SUN...SE wind 15 to 30 kt. Seas 11 to 19 ft.

$$

PKZ352-070145-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
318 AM AKST Wed Dec 6 2017

.TODAY...NE wind 15 to 30 kt. Seas 11 to 19 ft.
.TONIGHT...SE wind 15 to 30 kt. Seas 12 to 18 ft.
.THU...SE wind 15 to 30 kt. Seas 11 to 15 ft. Rain.
.THU NIGHT...S wind 15 to 30 kt. Seas 10 to 16 ft.
.FRI THROUGH SUN...SE wind 15 to 30 kt. Seas 10 to 18 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
638 PM AKST Sun Dec 3 2017

.ANALYSIS AND UPPER LEVELS...
The main feature today the developing storm center approaching
the western Gulf and the leading frontal trough. Gale to storm
force winds in advance of these two features are spreading north
across the Gulf. Strong gap flows are also developing across
Turnagain Arm and Portage Valley along with a barrier jet over the
North Gulf Coast. The brunt of the rain and snow are along the
coasts and cross barrier flow over the Chugach and Kenai Mountains
are limiting precipitation inland except for upslope areas along
the Alaska range near the western Susitna Valley and Cook inlet.
Elevated freezing levels are providing for a light wintry mix of
precipitation across the Anchorage Bowl.

Further west...the occluded front is pushing north and west
across Bristol Bay. Temperatures east of Dillingham and up toward
Dillingham are well above freezing with temps to the west below.
So rain is generally falling in the eastern portion of Bristol Bay
region, with a mix or some light freezing rain falling to the
west with warm overrunning air. Snow is spreading west across the
Kuskokwim Delta and with increasing winds should lower
visibilities in blowing snow. Satellite imagery showers a broad
area of open cell cumulus associated with snow/mixed showers
across much of the central/western Aleutians and Bering Sea.

&&

.MODEL DISCUSSION...
Models are in fairly good agreement with current storm center
heading north toward Kodiak. Wind and QPF fields are also
generally fairly close. Model consensus however starts to fall
apart Tue and Wed.

&&

.AVIATION...
PANC...Generally VFR conditions with a light wintry mix of
precipitation through this evening. Wind shear concerns will also
persist through tonight as surface northwesterlies strengthen
while southeast winds dominate up above the surface. Strong and
gusty south winds will develop across the airport complex by mid
morning monday.

&&

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
A strong low pressure system currently just south of Kodiak Island
will continue tracking north/northwest tonight and move into SW
Alaska while weakening through the day tomorrow. Most of the
action is out ahead of the low center where a strong warm front is
moving across Southcentral and into Prince William Sound,
bringing warm moist air and a large swath of heavy precipitation
up into the region. Precipitation type will continue to be a
challenge with this system as warm air is overriding cooler air at
the surface. Though most coastal locations will see rain, a few
places, including Valdez, may see snow continue this evening as
cold air entrenched in the valleys take its time mixing out.
Strong winds will also accompany this front, especially in the
typical terrain gaps like Turnagain Arm, where gusts will reach as
high as 70 mph this evening and tonight. These winds will also
lead to downsloping on the west side of the mountains so populated
places from the Kenai north to the Mat-Su Valley should see
little in the way of precipitation. Temperatures will also warm
tonight and should remain well above freezing through tomorrow.

Heavy precipitation along the Gulf Coast will continue through
most of the day tomorrow leading to significant snowfall
accumulations in the coastal mountains of the Kenai and Chugach
Ranges. Snow totals in the high peaks through the end of the day
tomorrow will be between 2-4 ft which will lead to increased
avalanche danger in the mountains.

As the low lifts north tomorrow afternoon, colder air will wrap
around the backside of the low and advect into southcentral. This
will help to bring strong southwest winds up Cook Inlet and into
the Kenai and Anchorage areas in the afternoon and evening hours.
On Tuesday, an upper level trough digs deep into the North
Pacific which will send up another low from the south bringing
the next round of heavy precipitation to the coast as downsloping
again keeps the populated areas mostly dry.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
A strong area of low pressure near Chirikof Island this afternoon
will continue to lift off to the north through the evening, as it
tracks from just east of King Salmon towards the lower Kuskokwim
Delta. An inverted trough ahead of this feature will continue to
move off to the northwest, with a shallow wedge of warmer air
having made it into parts of the region generally east of a
Dillingham to Sleetmute line. Here, precipitation has changed over
to a mix of rain and snow or just plain rain as temperatures
continue to climb a few degrees above freezing. This freezing line
will move slowly northwest through the evening before stalling,
as the low crosses the region tonight into Monday.

Ahead of the inverted trough, light to moderate snowfall will
develop with visibilities below two miles at times. Gusty
northeast winds preceding this front may aid with the visibility
restrictions, causing some blowing and drifting. Thus, we left
blowing snow in the forecast for the Kuskokwim Delta. Further
east, any rain or mixed precipitation will change back to snow
overnight as colder air wraps back into the region around the
periphery of the low. Colder and drier conditions are expected for
Tuesday as the low continues to depart the region.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
As the low mentioned above crosses eastern portions of the AKpen,
warmer air ahead of the system will allow temperatures to climb
above freezing, allowing for a few hours of rain or a rain snow
mix. Later tonight, colder air advecting back into the region will
change allow snow to become the dominant precipitation type once
again. What will be more noticeable is strong wind gusts for the
eastern portions of the peninsula and Bristol Bay region, due to a
tightening pressure gradient between this storm and another one
located across the western Bering Sea. Precipitation chances will
continue to slowly decrease through Tuesday as the system departs
the area.

Further west, a strong area of low pressure will meander its way
south from the western Bering this evening to central portions of
the chain by midday Tuesday. Temperatures across the western half
of the Aleutians and most of the Bering are cold enough that the
main impacts from this western storm will be gusty northwest winds
accompanied by periods of snow showers. By Tuesday evening,
decreasing winds with somewhat drier conditions will begin to
encompass all of the area.

&&

.LONG TERM FORECAST (Days 3 through 7)...
The mid term forecast beginning Tuesday night has ridging sitting
over southeast Alaska with a low tracking up the western side of
the ridge towards the Gulf. This setup will lead to a steady
stream of moisture being pumped into the north Gulf coast through
much of Wednesday. All models generally have this setup but vary
significantly on the location of the low and moisture fetch. This
means that there is high confidence that some areas along the
north Gulf coast will see high QPF amounts, however, there remains
uncertainty as to which areas will see those high amounts.

There is also an issue with how much warm air will be pulled up
from the south. This could lead to some areas along the coast
seeing rain instead of snow. Also, depending on the setup, the
Copper River Basin could see higher than normal amounts of snow
during this event. Uncertainty is high for the event.

For the long term forecast, inconsistency grows through the day 8
forecast as a strong ridge begins to build over the west coast of
the lower 48. This pattern looks to be very active, especially
for the Gulf and South Mainland which will be under the influence
of a strong southerly jet with the potential for a series of fast
moving systems through the Gulf through the upcoming work week.
As has been the case for the past few days, the models are struggling
with placement of these lows leading to ensembles being the choice
guidance. The one area where there is some agreement is with a
potentially sub 960 mb low moving toward the Western Aleutians on
Saturday. However, the potential track of this low after Saturday
varies wildly.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...Winter Weather Advisory 155.
MARINE...Storm Warning 119 125 130 132 138.
         Gale Warning 120 128 129 131 139 140 141
                      150 155 160 165 177 178 180.

&&

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