Gale Warning 468, NWS Anchorage, AK

252 
FZAK61 PAFC 042258
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
258 PM AKDT Wed Oct 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.

PKZ399-051330-
258 PM AKDT Wed Oct 4 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A strong front will enter the western Gulf tonight then move to 
the eastern Gulf Thu afternoon. A 990 mb low will develop along 
the front near 60N 150W Thu morning then move inland near 61N 
147W Thu afternoon. A trough of low pressure will remain over the 
northern Gulf Thu through Fri. 

$$

PKZ351-051330-
Gulf of Alaska Offshore North of 57N and West of 144W-
258 PM AKDT Wed Oct 4 2017

...GALE WARNING THURSDAY AND THURSDAY NIGHT...

.TONIGHT...S wind 15 to 25 kt. Seas 5 to 8 ft. Rain.
.THU...SW wind 20 to 35 kt. Seas 8 to 13 ft. Rain.
.THU NIGHT...W wind 40 kt. Seas 14 to 19 ft.
.FRI...W wind 30 to 40 kt. Seas 17 to 22 ft.
.FRI NIGHT...W wind 25 to 40 kt. Seas 14 to 21 ft.
.SAT...W wind 20 to 35 kt. Seas 10 to 18 ft.
.SUN THROUGH MON...SW wind 20 kt. Seas 4 to 9 ft.

$$

PKZ352-051330-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
258 PM AKDT Wed Oct 4 2017

...GALE WARNING THROUGH THURSDAY NIGHT...

.TONIGHT...SW wind 10 to 20 kt increasing to 20 to 35 kt after
midnight. Seas 7 to 11 ft. Rain.
.THU...SW wind 25 to 40 kt. Seas 9 to 13 ft. Rain.
.THU NIGHT...W wind 30 to 40 kt. Seas 13 to 20 ft.
.FRI...W wind 40 kt. Seas 17 to 24 ft.
.FRI NIGHT...W wind 25 to 40 kt. Seas 13 to 21 ft.
.SAT...W wind 15 to 30 kt. Seas 9 to 17 ft.
.SUN THROUGH MON...W wind 20 kt. Seas 5 to 10 ft.

$$

410 
FZAK61 PAFC 051156
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
356 AM AKDT Thu Oct 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.

PKZ399-060045-
356 AM AKDT Thu Oct 5 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A strong front move across the Gulf into today. A trough of low 
pressure will remain over the northern Gulf tonight through Fri
night.

$$

PKZ351-060045-
Gulf of Alaska Offshore North of 57N and West of 144W-
356 AM AKDT Thu Oct 5 2017

...GALE WARNING THROUGH FRIDAY...

.TODAY...SW wind 25 to 35 kt. Seas 8 to 13 ft. Rain.
.TONIGHT...W wind 30 to 40 kt. Seas 14 to 21 ft.
.FRI...W wind 30 to 40 kt. Seas 18 to 23 ft.
.FRI NIGHT...W wind 25 to 40 kt. Seas 14 to 22 ft.
.SAT THROUGH MON...W wind 20 to 35 kt. Seas 9 to 14 ft.

$$

PKZ352-060045-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
356 AM AKDT Thu Oct 5 2017

...GALE WARNING THROUGH FRIDAY...

.TODAY...SW wind 25 to 35 kt. Seas 9 to 14 ft. Rain.
.TONIGHT...W wind 30 to 45 kt. Seas 15 to 23 ft.
.FRI...W wind 45 kt. Seas 21 to 26 ft.
.FRI NIGHT...W wind 30 to 40 kt. Seas 14 to 26 ft.
.SAT THROUGH SUN...SW wind 15 to 30 kt. Seas 9 to 17 ft.
.MON...W wind 20 kt. Seas 8 ft.

$$

297 
FZAK61 PAFC 052339
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
339 PM AKDT Thu Oct 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.

PKZ399-061415-
339 PM AKDT Thu Oct 5 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A front along the northern Gulf coast will move inland and weaken 
this evening. A 985 mb low at 60N 146W will move inland tonight 
near 60N 143W at 986 mb. A trough of low pressure will persist
along the northern Gulf through Fri night. A front will approach
the southwest Gulf Sat afternoon.


$$

PKZ351-061415-
Gulf of Alaska Offshore North of 57N and West of 144W-
339 PM AKDT Thu Oct 5 2017

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...W wind 30 to 40 kt. Seas 14 to 21 ft.
.FRI...W wind 25 to 40 kt. Seas 17 to 22 ft.
.FRI NIGHT...W wind 25 to 40 kt. Seas 14 to 21 ft.
.SAT...W wind 20 to 35 kt. Seas 10 to 17 ft.
.SAT NIGHT...SW wind 15 to 30 kt. Seas 6 to 11 ft.
.SUN...SW wind 30 to 45 kt. Seas 14 to 22 ft.
.MON THROUGH TUE...NW wind 10 to 20 kt. Seas 6 to 10 ft.

$$

PKZ352-061415-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
339 PM AKDT Thu Oct 5 2017

...GALE WARNING THROUGH FRIDAY NIGHT...

.TONIGHT...W wind 30 to 45 kt. Seas 16 to 24 ft.
.FRI...W wind 45 kt. Seas 22 to 26 ft.
.FRI NIGHT...W wind 40 kt. Seas 15 to 25 ft.
.SAT...W wind 15 to 30 kt. Seas 9 to 17 ft.
.SAT NIGHT...SW wind 20 to 35 kt. Seas 9 to 17 ft.
.SUN...SW wind 30 to 45 kt. Seas 14 to 22 ft.
.MON THROUGH TUE...NW wind 20 kt. Seas 8 ft.

$$

235 
FZAK61 PAFC 061148
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
348 AM AKDT Fri Oct 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.

PKZ399-070045-
348 AM AKDT Fri Oct 6 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 994 mb low at 55N 162W Sat afternoon will move into the 
southwestern Gulf Sat night, then to 58N 153W at 988 mb Sun 
morning.

$$

PKZ351-070045-
Gulf of Alaska Offshore North of 57N and West of 144W-
348 AM AKDT Fri Oct 6 2017

...GALE WARNING THROUGH TONIGHT...

.TODAY...W wind 25 to 40 kt. Seas 15 to 21 ft.
Isolated thunderstorms.
.TONIGHT...NW wind 20 to 35 kt. Seas 13 to 20 ft.
.SAT...W wind 15 to 30 kt. Seas 8 to 16 ft.
.SAT NIGHT...S wind 20 to 35 kt. Seas 8 to 13 ft.
.SUN...W wind 30 to 40 kt. Seas 14 to 29 ft.
.MON...W wind 25 to 40 kt. Seas 13 to 21 ft.
.TUE...NW wind 20 kt. Seas 7 to 10 ft.

$$

PKZ352-070045-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
348 AM AKDT Fri Oct 6 2017

...GALE WARNING THROUGH TONIGHT...

.TODAY...W wind 35 to 45 kt. Seas 21 to 25 ft. 
Isolated thunderstorms.
.TONIGHT...W wind 40 kt. Seas 15 to 25 ft.
.SAT...W wind 20 to 30 kt. Seas 10 to 18 ft.
.SAT NIGHT...SW wind 30 to 45 kt. Seas 11 to 19 ft.
.SUN...W wind 30 to 45 kt. Seas 16 to 31 ft.
.MON...W wind 20 to 35 kt. Seas 14 to 22 ft.
.TUE...NW wind 25 kt. Seas 10 ft.

$$

985 
FZAK61 PAFC 062256
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
256 PM AKDT Fri Oct 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.

PKZ399-071245-
256 PM AKDT Fri Oct 6 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A trough of low pressure along the northern Gulf coast will weaken
through Sat morning. A front will move into the southwestern Gulf
Sat morning and will move to the eastern Gulf Sun morning. The
associated 988 mb Aleutian low mb enters the western Gulf Sat 
night at 58N 152W and then moves to 60N 146W Sun afternoon at 
990 mb.

$$

PKZ351-071245-
Gulf of Alaska Offshore North of 57N and West of 144W-
256 PM AKDT Fri Oct 6 2017

...GALE WARNING TONIGHT AND SATURDAY NIGHT...

.TONIGHT...NW wind 20 to 35 kt. Seas 13 to 19 ft.
.SAT...W wind 15 to 30 kt. Seas 8 to 16 ft.
.SAT NIGHT...SW wind 15 to 30 kt becoming S 25 to 40 kt after
midnight. Seas 7 to 10 ft building to 9 to 17 ft after midnight.
Rain.
.SUN...SW wind 30 to 40 kt. Seas 15 to 28 ft.
.SUN NIGHT...W wind 30 to 40 kt. Seas 17 to 26 ft.
.MON...W wind 25 to 40 kt. Seas 12 to 20 ft.
.TUE THROUGH WED...NW wind 10 to 20 kt. Seas 5 to 10 ft.

$$

PKZ352-071245-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
256 PM AKDT Fri Oct 6 2017

...GALE WARNING TONIGHT AND SATURDAY NIGHT...

.TONIGHT...W wind 40 kt. Seas 15 to 23 ft.
.SAT...W wind 20 to 30 kt. Seas 10 to 18 ft.
.SAT NIGHT...SW wind 20 to 35 kt increasing to 30 to 45 kt after
midnight. Seas 11 to 19 ft. Rain.
.SUN...W wind 35 to 45 kt. Seas 16 to 31 ft.
.SUN NIGHT...W wind 30 to 40 kt. Seas 16 to 26 ft.
.MON...W wind 20 to 35 kt. Seas 12 to 19 ft.
.TUE THROUGH WED...NW wind 25 kt. Seas 9 ft.

$$

319 
FZAK61 PAFC 071144
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
344 AM AKDT Sat Oct 7 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.

PKZ399-080045-
344 AM AKDT Sat Oct 7 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A strong front will move into the southwestern Gulf today,
crossing to the northeastern Gulf through Sun morning. A 986 mb 
Aleutian low at 58N 152W and will move to 60N 146W at 991 mb by 
Sun afternoon then move to 59N 143W at 1001 mb by Mon morning.

$$

PKZ351-080045-
Gulf of Alaska Offshore North of 57N and West of 144W-
344 AM AKDT Sat Oct 7 2017

...GALE WARNING TONIGHT AND SUNDAY...

.TODAY...W wind 15 to 30 kt becoming 20 kt in the afternoon. Seas
9 to 14 ft.
.TONIGHT...S wind 20 to 35 kt increasing to 35 to 45 kt after
midnight. Seas 7 to 11 ft building to 11 to 19 ft after midnight.
Rain.
.SUN...SW wind 45 kt. Seas 17 to 28 ft. Rain showers.
.SUN NIGHT...W wind 30 to 45 kt. Seas 17 to 25 ft.
.MON...W wind 25 to 40 kt. Seas 11 to 19 ft.
.TUE THROUGH WED...W wind 15 to 30 kt. Seas 7 to 11 ft.

$$

PKZ352-080045-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
344 AM AKDT Sat Oct 7 2017

...STORM WARNING TONIGHT...

.TODAY...W wind 20 to 30 kt. Seas 10 to 18 ft.
.TONIGHT...S wind 25 to 40 kt becoming SW 35 to 50 kt after
midnight. Seas 9 to 16 ft building to 15 to 23 ft after midnight.
.SUN...W wind 35 to 45 kt. Seas 18 to 28 ft.
.SUN NIGHT...W wind 40 kt. Seas 17 to 24 ft.
.MON...W wind 25 to 40 kt. Seas 11 to 19 ft.
.TUE THROUGH WED...W wind 15 to 25 kt. Seas 8 to 12 ft.

$$

925 
FZAK61 PAFC 072301
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
301 PM AKDT Sat Oct 7 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.

PKZ399-081330-
301 PM AKDT Sat Oct 7 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A strong front will slide across the Northern Gulf through Sun 
afternoon. A 985 mb low forms near 59N 152W Sun morning and moves
to 61N 147W then inland Sun afternoon. The trailing front 
continues over the Gulf for Mon afternoon. A 1001 mb low forms Mon
morning at 59N 141W and moves to 58N 137W at 1009 mb by Mon 
afternoon.

$$

PKZ351-081330-
Gulf of Alaska Offshore North of 57N and West of 144W-
301 PM AKDT Sat Oct 7 2017

...GALE WARNING THROUGH SUNDAY NIGHT...

.TONIGHT...S wind 20 to 35 kt increasing to 35 to 45 kt after
midnight. Seas 10 to 18 ft. Rain.
.SUN...SW wind 45 kt. Seas 20 to 29 ft. Rain showers.
.SUN NIGHT...W wind 30 to 45 kt. Seas 17 to 25 ft.
.MON...NW wind 25 to 40 kt. Seas 12 to 20 ft.
.MON NIGHT...W wind 30 kt. Seas 10 to 14 ft.
.TUE THROUGH THU...SW wind 15 to 30 kt. Seas 7 to 11 ft.

$$

PKZ352-081330-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
301 PM AKDT Sat Oct 7 2017

...STORM WARNING THROUGH SUNDAY...

.TONIGHT...S wind 25 to 35 kt becoming SW 35 to 50 kt after 
midnight. Seas 10 to 17 ft building to 13 to 27 ft after midnight.
.SUN...W wind 35 to 50 kt. Seas 19 to 29 ft.
.SUN NIGHT...W wind 40 kt. Seas 17 to 24 ft.
.MON...W wind 30 to 40 kt. Seas 13 to 21 ft.
.MON NIGHT...W wind 30 kt. Seas 9 to 17 ft.
.TUE THROUGH THU...SW wind 15 to 25 kt. Seas 8 to 11 ft.

$$

865 
FZAK61 PAFC 081129
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
329 AM AKDT Sun Oct 8 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.

PKZ399-090100-
329 AM AKDT Sun Oct 8 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 988 mb low near 59N 151W will move to 60N 147W at 989 mb this
afternoon and then weaken to 1000 mb as it moves to 59N 142W Mon
morning before moving into the eastern Gulf of Alaska. High
pressure will build across the western Gulf of Alaska Mon afternoon.

$$

PKZ351-090100-
Gulf of Alaska Offshore North of 57N and West of 144W-
329 AM AKDT Sun Oct 8 2017

...GALE WARNING THROUGH MONDAY...

.TODAY...SW wind 45 kt. Seas 18 to 28 ft. Rain.
.TONIGHT...W wind 30 to 45 kt. Seas 16 to 24 ft.
.MON...NW wind 25 to 40 kt. Seas 12 to 20 ft.
.MON NIGHT...W wind 20 to 30 kt. Seas 9 to 14 ft.
.TUE THROUGH WED...W wind 15 to 30 kt. Seas 6 to 11 ft.
.THU...SW wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ352-090100-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
329 AM AKDT Sun Oct 8 2017

...STORM WARNING TODAY...

.TODAY...W wind 35 to 50 kt. Seas 19 to 29 ft.
.TONIGHT...W wind 40 kt. Seas 17 to 25 ft.
.MON...NW wind 40 kt. Seas 14 to 22 ft.
.MON NIGHT...W wind 30 kt. Seas 9 to 17 ft.
.TUE THROUGH THU...SW wind 15 to 25 kt. Seas 8 to 13 ft.

$$

254 
FZAK61 PAFC 082337
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
337 PM AKDT Sun Oct 8 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.

PKZ399-091245-
337 PM AKDT Sun Oct 8 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 994 mb low at 60N 145W exits the Southeastern Gulf at 1011 mb 
Mon afternoon. The associated front will decay over Southcentral
Alaska through Tue afternoon. A trough remains along the North 
Gulf Coast through Tue afternoon. High pressure slides into the
Western Gulf Mon afternoon.

$$

PKZ351-091245-
Gulf of Alaska Offshore North of 57N and West of 144W-
337 PM AKDT Sun Oct 8 2017

...GALE WARNING THROUGH MONDAY...

.TONIGHT...W wind 25 to 40 kt. Seas 16 to 23 ft.
.MON...NW wind 25 to 40 kt. Seas 11 to 19 ft.
.MON NIGHT...W wind 20 to 30 kt. Seas 10 to 14 ft.
.TUE...W wind 20 to 30 kt. Seas 9 ft.
.TUE NIGHT...W wind 25 kt. Seas 9 ft.
.WED THROUGH FRI...SW wind 10 to 25 kt. Seas 7 to 12 ft.

$$

PKZ352-091245-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
337 PM AKDT Sun Oct 8 2017

...GALE WARNING THROUGH MONDAY...

.TONIGHT...W wind 40 kt. Seas 17 to 23 ft.
.MON...NW wind 25 to 40 kt. Seas 13 to 21 ft.
.MON NIGHT...W wind 30 kt. Seas 8 to 16 ft.
.TUE...W wind 25 kt. Seas 7 to 10 ft.
.TUE NIGHT...W wind 25 kt. Seas 9 ft.
.WED THROUGH FRI...SW wind 15 to 25 kt. Seas 9 to 14 ft.

$$

880 
FZAK61 PAFC 091139
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
339 AM AKDT Mon Oct 9 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.

PKZ399-100200-
339 AM AKDT Mon Oct 9 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 1002 mb low near 59N 142W will move into the eastern Gulf of
Alaska by late this morning. A lingering trough of low pressure
will remain along the northern gulf coast through Tue morning.
High pressure will build across the western Gulf of Alaska through
Tue night.

$$

PKZ351-100200-
Gulf of Alaska Offshore North of 57N and West of 144W-
339 AM AKDT Mon Oct 9 2017

...GALE WARNING TODAY...

.TODAY...NW wind 25 to 40 kt. Seas 11 to 18 ft.
.TONIGHT...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.TUE...W wind 20 to 30 kt. Seas 8 to 11 ft.
.TUE NIGHT...W wind 20 to 30 kt. Seas 8 to 11 ft.
.WED...W wind 10 to 25 kt. Seas 5 to 9 ft.
.THU...SW wind 10 to 25 kt. Seas 5 to 10 ft.
.FRI...W wind 30 kt. Seas 10 to 15 ft.

$$

PKZ352-100200-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
339 AM AKDT Mon Oct 9 2017

...GALE WARNING TODAY...

.TODAY...NW wind 25 to 40 kt. Seas 13 to 20 ft.
.TONIGHT...NW wind 30 kt. Seas 8 to 16 ft.
.TUE...W wind 25 kt. Seas 7 to 10 ft.
.TUE NIGHT...W wind 25 kt. Seas 9 ft.
.WED THROUGH FRI...W wind 15 to 25 kt. Seas 7 to 12 ft.

$$

219 
FZAK61 PAFC 092315
OFFAER

Offshore Waters Forecast
National Weather Service Anchorage AK
315 PM AKDT Mon Oct 9 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.

PKZ399-101245-
315 PM AKDT Mon Oct 9 2017
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A weak trough of low pressure over the northern Gulf coast 
remains nearly stationary through Tue afternoon. A ridge of high 
pressure builds over the Gulf through Wed afternoon.

$$

PKZ351-101245-
Gulf of Alaska Offshore North of 57N and West of 144W-
315 PM AKDT Mon Oct 9 2017

.TONIGHT...NW wind 15 to 30 kt. Seas 8 to 13 ft.
.TUE...W wind 20 to 30 kt. Seas 9 ft.
.TUE NIGHT...W wind 20 to 30 kt. Seas 8 to 11 ft.
.WED...W wind 15 to 25 kt. Seas 8 ft.
.WED NIGHT...W wind 20 kt. Seas 6 to 9 ft.
.THU...SW wind 10 to 25 kt. Seas 6 to 10 ft.
.FRI THROUGH SAT...SW wind 15 to 30 kt. Seas 9 to 14 ft.

$$

PKZ352-101245-
Gulf of Alaska Offshore South of 57N North of 55N and West of
144W-
315 PM AKDT Mon Oct 9 2017

.TONIGHT...NW wind 30 kt. Seas 9 to 14 ft.
.TUE...W wind 25 kt. Seas 7 to 10 ft.
.TUE NIGHT...W wind 25 kt. Seas 9 ft.
.WED...W wind 25 kt. Seas 7 to 10 ft.
.WED NIGHT...W wind 25 kt. Seas 7 to 10 ft.
.THU THROUGH SAT...SW wind 15 to 30 kt. Seas 8 to 13 ft.

$$

Southcentral and Southwest Alaska Forecast Discussion
National Weather Service Anchorage AK
454 PM AKDT Tue Oct 3 2017

.ANALYSIS AND UPPER LEVELS...

The large scale pattern features a trough over the western part of
the state extending well south into the northern Pacific. At the
base of the trough lies a weakening vertically stacked low that is
opening into a wave this afternoon. Downstream of the trough a
ridge holds steady over western Canada. The upstream trough is
just starting to acquire a slight negative tilt as it banks up
against the base of the ridge to the east. Between the two upper
level features, an atmospheric river continues to pump subtropical
moisture to the northeast Gulf coast. Radar imagery shows the
western fringe of this moisture, currently over eastern Prince
William Sound, spreading west this afternoon toward Southcentral.

Further west, showers over the Kuskokwim Delta associated with a
departing low are just starting to weaken this afternoon. A strong
jet streak aloft and rather impressive low-level baroclinicity
associated with a surface front over the western Aleutians is
priming the western Bering for the development of a strong low
this evening. This low will be the main weather-maker over the
coming days.

&&

.MODEL DISCUSSION...
The models remain in general synoptic agreement. However, there
are some minor differences in timing and intensity with the low
and associated front tracking through the Bering/Aleutians today
through Wednesday. It seems reasonable as the two main features
which affect Alaska develop under fairly strong upper jets. The
first feature traveling north into the Gulf today appears best
captured by the NAM/GFS models. The next big storm moving across
the Bering Sea today through Thursday is also best captured by the
NAM/GFS, bringing strong winds and higher seas to much of the
Bering and Aleutians.

&&

.AVIATION...
VFR conditions will continue through today, but will likely drop
under 5000 ft this evening as rain begins to fall over the
Anchorage bowl.

.SHORT TERM FORECAST SOUTHCENTRAL ALASKA (Days 1 and 2)...
Rain will quickly spread westward back into Southcentral early
this evening as the Gulf low slowly moves into Prince William
Sound and dissipates. This low will be strong enough to cause a
brief increase in the gap winds throughout Prince William Sound as
it passes through, all of which should then diminish by late
tonight. Rain will then continue in most areas into Wednesday,
giving little if any break in the weather before a gale force
front moves through the Gulf late Wednesday-Thursday. It is with
this feature that most of the forecast updates were made today,
mostly with increasing winds throughout the Gulf and gusty gap
winds from Turnagain Arm eastward into the Copper River area.
While a weak lee side low is expected to develop behind this
front, a strong pressure gradient created from a much deeper low
over the west coast will be the primary driver for gusty winds
that are expected to develop over the Anchorage Bowl and Matanuska
Valley on Thursday. There will be some downsloping associated
with these winds, however with winds quickly becoming
southwesterly aloft this will likely not be strong enough to
prevent rain from falling over the downslope prone areas on the
lee side of the Chugach for most of the day Thursday. Conditions
throughout the area will begin to slowly improve on Friday, but
with continued cyclonic flow aloft most areas will remain cloudy
and showery to end the work week.

&&

.SHORT TERM FORECAST SOUTHWEST ALASKA (Days 1 and 2)...
There is an upper level trough over the Kuskokwim Delta so expect
light showers to continue overnight as this feature pushes inland.
After a short break between storms, the main event is expected to
begin tomorrow as a low pressure system rapidly intensifies over
the Bering Sea. The leading edge of the precipitation shield will
reach western Alaska tomorrow afternoon with the bulk of the QPF
expect late Wednesday night and into Thursday morning. The tight
pressure gradient will hold up through Thursday and widespread
gusty winds are anticipated. A long fetch of strong westerly winds
will also lead to increased surge and the potential of minor
coastal flooding and beach erosion. Right now, the highest
potential for flooding looks to be for locations along Kuskokwim
Bay, including Quinhagak and Goodnews Bay, where water levels
could be 2-3 feet above high astronomical tide on Thursday. See
the Special Weather Statement for more information.

&&

.SHORT TERM FORECAST BERING SEA/ALEUTIANS (Days 1 and 2)...
A strong jet parallels the Aleutian Chain this forecast period.
Expect rough seas, strong winds and rapid cyclogenesis. This is a
high confidence event, with multiple solutions progging a minimum
central pressure of around 960 mb by Wednesday night. The low
will trek across the Central Bering on Wednesday and Thursday.

&&

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

The extended forecast period begins Thursday night with the
remnants of a powerful Bering sea storm moving eastward into
Southern Alaska. This strong cyclone will still be impacting
Bristol Bay and the Alaska Peninsula with strong gale force winds
with the strongest core of winds moving into the Gulf of Alaska
Friday. Strong mid level westerly flow will be supporting a well
defined upslope/downslope pattern with most lower elevations areas
drying out while precipitation favors higher mountain slopes.
This pattern regime will persist through Saturday before the
pressure gradient weakens and a trough digs out over the Bering
Sea. Much uncertainty develops at this juncture as the global
models diverge rapidly with the development of a surface low along
the subtropical warm front. The Canadian GDPS and GFS prefer to
phase the upper trough with the entire warm front, creating a much
deeper and slower moving low while the ECMWF has a faster moving
low and a lower amplitude trough. The differences become stark by
Sunday as the ECMWF is racing the low across northern Gulf of
Alaska while the Canadian and GFS depict a deep low south of the
Eastern Aleutians. Long story short, we continue to favor a WPC
blend approach which favors more stable ensemble solutions showing
a weaker low moving north toward the AK Peninsula Sunday and
Monday with increasing chances for precipitation into the early
week.

&&

.AFC WATCHES/WARNINGS/ADVISORIES...
PUBLIC...None.
MARINE...Gale 119 130-132 139 155-170 172-178 185.
		 Storm 179 180 181.

&&

SYNOPSIS AND MODEL DISCUSSION...RD
SOUTHCENTRAL ALASKA...DEK
SOUTHWEST ALASKA/BERING SEA/ALEUTIANS...PS
LONG TERM...JA