Gale Warning 535, NWS Anchorage, AK

224 
FZAK61 PAFC 311156
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT WED AUG 31 2011

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.

PKZ399-010300-
400 AM AKDT WED AUG 31 2011
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...
A 1008 MB LOW NEAR 58N 152W WILL STRENGTHEN TO 1002 MB AS IT MOVES TO
NEAR 59N 140W WED NIGHT. A 1004 MB LOW NEAR 53N 153W ON THU AFTERNOON
WILL STRENGTHEN TO 995 MB AS IT MOVES TO NEAR 56N 147W THU NIGHT.
$$

PKZ351-010300-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT WED AUG 31 2011

...GALE WARNING TONIGHT...

.TODAY...S WIND 20 KT BECOMING SW 30 KT IN THE AFTERNOON. SEAS 8 FT.
RAIN.
.TONIGHT...W WIND 35 KT. SEAS 11 FT. RAIN.
.THU...W WIND 30 KT. SEAS 12 FT. 
.THU NIGHT...SE WIND 30 KT. SEAS 10 FT. 
.FRI...S WIND 35 KT. SEAS 13 FT. 
.SAT...SW WIND 25 KT. SEAS 10 FT. 
.SUN...SE WIND 30 KT. SEAS 11 FT.  

$$

PKZ352-010300-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT WED AUG 31 2011

...GALE WARNING TONIGHT...

.TODAY...W WIND 30 KT. SEAS 9 FT. RAIN.
.TONIGHT...W WIND 35 KT. SEAS 12 FT. 
.THU...W WIND 30 KT BECOMING SW 20 KT IN THE AFTERNOON. SEAS 11 FT.
RAIN.
.THU NIGHT...SE WIND 30 KT. SEAS 11 FT. 
.FRI...W WIND 35 KT. SEAS 13 FT. 
.SAT...SW WIND 25 KT. SEAS 13 FT. 
.SUN...SE WIND 30 KT. SEAS 13 FT.  

$$

000 
FZAK61 PAFC 312334
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT WED AUG 31 2011

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.

PKZ399-011500-
400 PM AKDT WED AUG 31 2011
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 1005 MB LOW NEAR 58N 149W WILL STRENGTHEN TO 1002 MB AS IT MOVES TO
NEAR 59N 140W TONIGHT BEFORE MOVING INLAND. A 1005 MB LOW NEAR 53N
153W ON THU AFTERNOON WILL STRENGTHEN TO 991 MB AS IT MOVES TO NEAR
56N 149W THU NIGHT.

$$

PKZ351-011500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT WED AUG 31 2011

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

.TONIGHT...W WIND 35 KT. SEAS 10 FT. 
.THU...W WIND 25 KT. SEAS 10 FT. 
.THU NIGHT...S WIND 15 KT BECOMING SE 35 KT AFTER MIDNIGHT. SEAS
7 FT. RAIN.
.FRI...SE WIND 40 KT. SEAS 14 FT. 
.FRI NIGHT...SW WIND 30 KT. SEAS 15 FT. 
.SAT...SW WIND 25 KT. SEAS 12 FT. 
.SUN AND MON...SE WIND 30 KT. SEAS 9 FT. 

$$

PKZ352-011500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT WED AUG 31 2011

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

.TONIGHT...W WIND 35 KT. SEAS 12 FT. 
.THU...W WIND 30 KT BECOMING SW 20 KT IN THE AFTERNOON. SEAS 11 FT.
RAIN.
.THU NIGHT...SE WIND 35 KT. SEAS 9 FT. RAIN.
.FRI...SW WIND 35 KT. SEAS 14 FT. 
.FRI NIGHT...SW WIND 30 KT. SEAS 14 FT. 
.SAT...SW WIND 25 KT. SEAS 12 FT. 
.SUN AND MON...SE WIND 30 KT. SEAS 11 FT. 

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
120 PM AKDT TUE AUG 30 2011

.MODEL DISCUSSION...

MODELS ARE IN GENERALLY GOOD AGREEMENT IN THE SHORT TERM THROUGH
THURSDAY AFTERNOON. FROM THURSDAY THROUGH FRIDAY KEY DIFFERENCES
ARISE WITH REGARDS TO LOW PRESSURE DEVELOPMENT IN THE NORTH PACIFIC
SOUTH OF THE ALASKA PENINSULA WHICH THEN MOVES INTO THE GULF OF
ALASKA FRIDAY MORNING. THE PREFERRED SCENARIO FOR NOW FOLLOWS ALONG
THE LINES OF THE GFS AND OTHER MODELS IN SHOWING A MOSTLY NON-PHASING
SOLUTION AND A WEAKER SURFACE LOW IN THE GULF OF ALASKA FRIDAY INTO
SATURDAY. THE EUROPEAN MODEL (EC) CONSISTENTLY DEPICTS A PHASING
SCENARIO BETWEEN A DIGGING UPPER LOW PRESSURE SYSTEM OVER THE EASTERN
BERING AND A CUT-OFF LOW PRESSURE SYSTEM BEING ABSORBED INTO IT FROM
OVER THE NORTH PACIFIC. THIS RESULTS IN A FAR STRONGER LOW PRESSURE
SYSTEM IN THE GULF OF ALASKA WITH MUCH STRONGER SURFACE WINDS (A
LARGE SWATH OF GALES) ON FRIDAY. GIVEN THE GOOD TRACK RECORD OF THE
EC MODEL WE CAN NOT YET RULE OUT THE PHASING SCENARIO...SO THIS WILL
BEAR CLOSE WATCHING OVER THE NEXT DAY OR SO.

.ANALYSIS AND UPPER LEVELS...

A POTENT LOW PRESSURE SYSTEM IS CONSOLIDATING OVER THE EASTERN BERING
THIS AFTERNOON WHILE RIDGING ALOFT SITS OVER THE GULF OF ALASKA
EXTENDING NORTH THROUGH FAR EASTERN MAINLAND. RADAR DEPICTS A SOLID
WALL OF RAIN MOVING ONSHORE OF SOUTHWEST ALASKA AS THE PARENT SYSTEM
ORGANIZES OVER THE BERING AND BEGINS TO TAKE ON A NEGATIVE TILT. A
SOUTHWESTERLY 120-KNOT JET STREAK CURRENTLY LOCATED OVER THE EASTERN
ALEUTIANS WILL MOVE EAST AND STRENGTHEN TO OVER 140 KNOTS AT ITS CORE
TONIGHT...WITH THE NOSE OF THE JET EXTENDING TO THE NORTH GULF COAST
AND THE LOWER COOK INLET REGION LATE TONIGHT. THIS FEATURE WILL USHER
IN COPIOUS AMOUNTS OF MOISTURE AS THE LOW PRESSURE SYSTEM MOVES INTO
THE NORTHERN GULF ON WEDNESDAY...AND THE RESULT WILL BE A MOSTLY
STEADY RAIN OVER THE COOK INLET...SUSITNA VALLEY...AND NORTH GULF
COAST REGIONS TONIGHT THROUGH WEDNESDAY NIGHT. THURSDAY WILL SEE A
RETURN OF TRANSITORY RIDGING OVER THE REGION...BUT THIS WILL QUICKLY
GIVE WAY TO ANOTHER STRONG LOW DIGGING FROM THE BERING EAST INTO THE
SOUTHWEST GULF BY FRIDAY NIGHT.

.SHORT TERM FORECAST...

SOUTH AND EAST OF THE ALASKA RANGE...

WEAK LEAD DISTURBANCE CURRENTLY RESIDES OVER THE SUSITNA VALLEY AND
EXTENDS SOUTH AND EAST INTO THE NORTHERN GULF. THIS FEATURE WILL
BRING MOSTLY LIGHT RAIN AS IT TRACKS EAST THROUGH TONIGHT. THE MAIN
SYSTEM GETS FIRING TOWARDS MORNING AS A 140-KNOT JET STREAK NOSES
INTO THE REGION FROM THE SOUTHWEST. AS THE ORGANIZING PARENT LOW
MOVES EAST OVER SOUTHWEST ALASKA...AND THE LEFT EXIT REGION OF THE
JET STREAK MOVES OVER THE NORTHERN GULF COAST...EXPECT TO SEE STEADY
RAIN OVERSPREAD ALL OF INTERIOR SOUTHWEST ALASKA AND ALL OF
SOUTHCENTRAL ALASKA (WITH THE EXCEPTION OF PARTS OF THE COPPER RIVER
BASIN) BY LATE TOMORROW MORNING. THIS SYSTEM WILL BEGIN TO WIND DOWN
FROM WEST TO EAST LATE WEDNESDAY NIGHT AS IT RAPIDLY PROGRESSES
TOWARDS THE PANHANDLE...TO BE FOLLOWED ON ITS HEELS BY A PROGRESSIVE
RIDGE. THURSDAY MIGHT BE THE BEST DAY TO MAKE A TRIP TO THE FAIR
UNDER PARTLY SUNNY SKIES BEFORE THE NEXT SYSTEM DIGGING RAPIDLY SOUTH
AND EAST TOWARDS THE GULF BRINGS POSSIBLY ANOTHER SHOT OF RAIN TO THE
REGION BY FRIDAY...BUT THIS SYSTEM MIGHT BE CONFINED MORE TO THE
NORTHERN GULF COAST AS THERE IS STILL LOTS OF UNCERTAINTY TO THE
STRENGTH AND TRACK AT THIS TIME.

SOUTHWEST ALASKA...

A WET AND STORMY PATTERN WILL CONTINUE THROUGH THURSDAY...WITH A
POSSIBLE BRIEF REPRIEVE FRIDAY AND FRIDAY NIGHT AS TRANSITORY RIDGING
MOVES OVER THE REGION BEFORE THE NEXT SYSTEM AFFECTS THE REGION BY
SATURDAY.

BERING SEA/ALEUTIANS...

A VERY ACTIVE STORM TRACK WILL PERSIST FROM EASTERN RUSSIA OVER THE
NORTHERN BERING AND EXTENDING TOWARDS EAST TOWARDS THE GULF OF
ALASKA. THIS WILL RESULT IN PERIODS OF RAIN AS THESE SYSTEMS MOVE
THROUGH...WITH LOW-END GALES AFFECTING THE BERING OFFSHORE REGION
TONIGHT THROUGH WEDNESDAY NIGHT OUT AHEAD OF LOW PRESSURE MOVING OFF
THE EASTERN RUSSIA COAST TONIGHT.

.LONG TERM FORECAST...

THE ACTIVE ZONAL PATTERN WILL CONTINUE WITH SYSTEMS MOVING RAPIDLY
ACROSS THE BERING INTO THE GULF OF ALASKA THROUGH THE
WEEKEND...THOUGH THERE ARE HINTS AT A PATTERN CHANGE BY MONDAY AS
GLOBAL MODELS SUGGEST THE PROGRESSIVE FLOW EVOLVING INTO A HIGH
AMPLITUDE PATTERN BY EARLY NEXT WEEK WITH LOW PRESSURE NEAR THE
ALASKA PENINSULA AND KODIAK ISLAND...AND STRONG RIDGES OF HIGH
PRESSURE OVER WESTERN CANADA AND THE WESTERN BERING.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALES...
FIRE WEATHER...NONE.

29 AUG 11