Gale Warning 321, NWS Anchorage, AK

450 
FZAK61 PAFC 291142
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT THU APR 29 2010

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.

PKZ399-300200-
400 AM AKDT THU APR 29 2010
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 995 MB NORTH PACIFIC LOW WILL MOVE TO 56N 145W FRIDAY 
MORNING...THEN MOVE TO 57N 139W AT 999 MB EARLY SATURDAY MORNING.

$$

PKZ351-300200-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT THU APR 29 2010

.TODAY...S WIND 15 KT. SEAS 7 FT. 
.TONIGHT...SE WIND 15 KT BECOMING E 30 KT AFTER MIDNIGHT. SEAS 7 FT.
RAIN.
.FRI...E WIND 30 KT BECOMING N 25 KT IN THE AFTERNOON. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...NW WIND 25 KT. SEAS 10 FT. 
.SAT AND SUN...W WIND 25 KT. SEAS 10 FT. 
.MON...NW WIND 25 KT. SEAS 8 FT.  

$$

PKZ352-300200-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT THU APR 29 2010

...GALE WARNING TONIGHT AND FRIDAY...

.TODAY...SW WIND 15 KT. SEAS 9 FT. 
.TONIGHT...E WIND 25 KT...INCREASING TO 35 KT AFTER MIDNIGHT E OF
147W. SEAS 9 FT. RAIN AND SNOW. 
.FRI...N TO W WIND 25 TO 40 KT...STRONGEST E OF 147W. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...W WIND 25 TO 35 KT. SEAS 11 FT. 
.SAT...W WIND 25 KT. SEAS 10 FT. 
.SUN AND MON...W WIND 30 KT. SEAS 9 FT. 

$$

138 
FZAK61 PAFC 291645 RRA
OFFAER

OFFSHORE WATERS FORECAST...RETRANSMIT
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT THU APR 29 2010

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.

PKZ399-300200-
400 AM AKDT THU APR 29 2010
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 995 MB NORTH PACIFIC LOW WILL MOVE TO 56N 145W FRIDAY 
MORNING...THEN MOVE TO 57N 139W AT 999 MB EARLY SATURDAY MORNING.

$$

PKZ351-300200-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT THU APR 29 2010

.TODAY...S WIND 15 KT. SEAS 7 FT. 
.TONIGHT...SE WIND 15 KT BECOMING E 30 KT AFTER MIDNIGHT. SEAS 7 FT.
RAIN.
.FRI...E WIND 30 KT BECOMING N 25 KT IN THE AFTERNOON. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...NW WIND 25 KT. SEAS 10 FT. 
.SAT AND SUN...W WIND 25 KT. SEAS 10 FT. 
.MON...NW WIND 25 KT. SEAS 8 FT.  

$$

PKZ352-300200-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT THU APR 29 2010

...GALE WARNING TONIGHT AND FRIDAY...

.TODAY...SW WIND 15 KT. SEAS 9 FT. 
.TONIGHT...E WIND 25 KT...INCREASING TO 35 KT AFTER MIDNIGHT E OF
147W. SEAS 9 FT. RAIN AND SNOW. 
.FRI...N TO W WIND 25 TO 40 KT...STRONGEST E OF 147W. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...W WIND 25 TO 35 KT. SEAS 11 FT. 
.SAT...W WIND 25 KT. SEAS 10 FT. 
.SUN AND MON...W WIND 30 KT. SEAS 9 FT. 

$$

624 
FZAK61 PAFC 291705 RRB
OFFAER

OFFSHORE WATERS FORECAST...RETRANSMIT
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT THU APR 29 2010

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.

PKZ399-300200-
400 AM AKDT THU APR 29 2010
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 995 MB NORTH PACIFIC LOW WILL MOVE TO 56N 145W FRIDAY 
MORNING...THEN MOVE TO 57N 139W AT 999 MB EARLY SATURDAY MORNING.

$$

PKZ351-300200-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT THU APR 29 2010

.TODAY...S WIND 15 KT. SEAS 7 FT. 
.TONIGHT...SE WIND 15 KT BECOMING E 30 KT AFTER MIDNIGHT. SEAS 7 FT.
RAIN.
.FRI...E WIND 30 KT BECOMING N 25 KT IN THE AFTERNOON. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...NW WIND 25 KT. SEAS 10 FT. 
.SAT AND SUN...W WIND 25 KT. SEAS 10 FT. 
.MON...NW WIND 25 KT. SEAS 8 FT.  

$$

PKZ352-300200-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT THU APR 29 2010

...GALE WARNING TONIGHT AND FRIDAY...

.TODAY...SW WIND 15 KT. SEAS 9 FT. 
.TONIGHT...E WIND 25 KT...INCREASING TO 35 KT AFTER MIDNIGHT E OF
147W. SEAS 9 FT. RAIN AND SNOW. 
.FRI...N TO W WIND 25 TO 40 KT...STRONGEST E OF 147W. SEAS 10 FT.
RAIN AND SNOW. 
.FRI NIGHT...W WIND 25 TO 35 KT. SEAS 11 FT. 
.SAT...W WIND 25 KT. SEAS 10 FT. 
.SUN AND MON...W WIND 30 KT. SEAS 9 FT. 

$$

809 
FZAK61 PAFC 300000
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT THU APR 29 2010

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.

PKZ399-301400-
400 PM AKDT THU APR 29 2010
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 996 MB NORTH PACIFIC LOW WILL MOVE TO 55N 142W FRIDAY
MORNING...THEN MOVE INLAND NEAR 56N 135W AT 1003 MB EARLY SATURDAY
MORNING.
$$

PKZ351-301400-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT THU APR 29 2010

.TONIGHT...SE WIND 20 KT. SEAS 7 FT. 
.FRI...E WIND 25 KT. SEAS 8 FT. RAIN AND SNOW. 
.FRI NIGHT...NW WIND 20 KT. SEAS 9 FT. 
.SAT AND SAT NIGHT...W WIND 20 KT. SEAS 9 FT. 
.SUN...W WIND 25 KT. SEAS 8 FT. 
.MON AND TUE...NW WIND 25 KT. SEAS 8 FT. 

$$

PKZ352-301400-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT THU APR 29 2010

.TONIGHT...E WIND 25 KT. SEAS 8 FT. RAIN AND SNOW. 
.FRI...NW WIND 25 KT. SEAS 10 FT. RAIN.
.FRI NIGHT AND SAT...W WIND 25 KT. SEAS 9 FT. 
.SAT NIGHT...W WIND 20 KT. SEAS 9 FT. 
.SUN AND MON...W WIND 30 KT. SEAS 9 FT. 
.TUE...W WIND 25 KT. SEAS 8 FT.  

$$

AREA FORECAST DISCUSSION
SOUTHCENTRAL AND SOUTHWEST ALASKA
130 PM AKDT WED APR 28 2010

.ANALYSIS AND UPPER LEVELS...
LONG WAVE UPPER LEVEL TROUGH REMAINS IN PLACE OVER WESTERN ALASKA AND
THE BERING SEA. DOWNSTREAM...A HIGH AMPLITUDE UPPER LEVEL RIDGE HAS
BEEN CUT OFF FROM THE MAIN CIRCULATION AND IS DRIFTING NORTHWEST
ACROSS THE NORTHERN YUKON AND NORTHWEST TERRITORIES. THE JET IS STILL
WELL SOUTH OF OUR AREA OF RESPONSIBILITY BUT WILL NUDGE CLOSER LATER
THIS WEEK AS THE RIDGE LOSES GROUND AND THE TROUGH DIGS DEEPER TO THE
WEST...POINTING THE JET TOWARD THE ALASKA PANHANDLE.

AT THE SURFACE...A BROAD AREA OF LOW PRESSURE ENCOMPASSES THE GULF OF
ALASKA AND SOUTHCENTRAL ALASKA. THE ONLY DISCERNIBLE LOW ON SATELLITE
IS EMBEDDED IN THE EASTERLY FLOW ACROSS THE WESTERN GULF. A THERMAL
TROUGH IS ALSO EVIDENT ACROSS THE UPPER YUKON RIVER VALLEY...BRUSHING
UP AGAINST THE ALASKA RANGE AND THE NORTHERN SUSITNA AND COPPER RIVER
VALLEYS. OUT WEST...A WEAK AREA OF HIGH PRESSURE IS PREVALENT OVER
THE REGION WITH COLD NORTHWESTERLY FLOW BRINGING MUCH OF THE
SOUTHWEST COASTAL REGION AND THE EASTERN ALEUTIANS BELOW AVERAGE
TEMPERATURES.

.MODEL DISCUSSION...VERY LITTLE DIFFERENCES IN THE MODEL SOLUTIONS
THIS MORNING THROUGH 48 HOURS. THURSDAY NIGHT...A SURFACE LOW WILL
DEVELOP AND RAPIDLY MOVE NORTHEAST TOWARD THE GULF. THE MODELS HAVE
BEEN WILDLY INCONSISTENT WITH THE PLACEMENT AND STRENGTH OF THIS
FEATURE. THE GFS APPEARS TO BE A BIT MORE CONSISTENT THAN THE NAM OR
EC...SO THE FORECAST IS A BLEND OF THE LATEST GFS WITH THE INHERITED
FORECAST WHICH WAS BASED OFF OF THE PREVIOUS GFS. CONFIDENCE BEYOND
48 HOURS IS AVERAGE TO BELOW AVERAGE.

.SHORT TERM FORECAST...
SOUTHCENTRAL ALASKA...GIVEN THE UNCERTAINTY IN THE MEDIUM
RANGE...WILL FOCUS ON THE SHORT TERM FORECAST. THE AFOREMENTIONED LOW
IN THE GULF IS MOVING RAPIDLY WEST TOWARD KAMISHAK BAY THIS
AFTERNOON. RAIN WILL BE MAINLY LIMITED TO THE COASTAL ZONES
ASSOCIATED WITH THIS FEATURE. THE CHALLENGE IN THE FORECAST WILL BE
THE EFFECTS OF A THERMAL TROUGH NEAR THE ALASKA RANGE. CUMULUS JUST
NOW DEVELOPING NORTH OF THE RANGE WITH ONLY CIRRUS COVERING THE
NORTHERN PORTIONS OF OUR DOMAIN. THE POTENTIAL FOR AFTERNOON
CONVECTION WITH THE OUTSIDE CHANCE OF A STRAY LIGHTNING STRIKE EXISTS
WHERE THERE HAS BEEN LIMITED CLOUD COVERAGE...ALTHOUGH NOT CONFIDENT
ENOUGH TO MENTION THAT QUITE YET IN THE FORECAST.

THERE WILL BE SLIGHTLY COOLER TEMPERATURES ADVECTING TO THE WEST ON
THE BACKSIDE OF THE LOW MOVING INLAND. CLOUDS WILL THIN OUT AT TIMES
AND THEN INCREASE AGAIN AS THE NEXT WAVE APPROACHES THURSDAY SO
EXPECTING SOMEWHERE BETWEEN PARTLY TO MOSTLY CLOUDY SKIES ACROSS
SOUTHCENTRAL WITH CLOUDS AND RAIN CONTINUING ALONG THE GULF COAST.
STILL MUCH UNCERTAINTY IN THE LOW MOVING INTO THE GULF ON
FRIDAY...ALTHOUGH THE EFFECTS SHOULD MAINLY BE OVER THE WATER AND
ALONG THE COAST.

SOUTHWEST ALASKA...A DEFORMATION ZONE IS IN PLACE FROM THE ALASKA
PENINSULA UP TO THE SEWARD PENINSULA. COLD AIR AT THE SURFACE IS
BEING OVER RUN BY WARM AIR ALOFT...RESULTING IN WIDESPREAD LIGHT SNOW
ACROSS ZONE 161. THIS AREA OF SNOW WILL DISSIPATE AS IT DRIFTS WEST
THIS AFTERNOON...BUT A SECOND AREA WILL DEVELOP LATER THIS EVENING AS
THE MAIN LOW MOVES INLAND. INITIALLY...THIS LOW WILL BRING WARMER AIR
SO SNOW WILL TRANSITION OVER TO RAIN OR A RAIN AND SNOW MIX
OVERNIGHT. COLD AIR WRAPS AROUND THE BACKSIDE OF THE LOW BUT NOT
UNTIL THE MOISTURE IS CUT OFF...RESULTING IN SNOW SHOWERS THROUGH THE
REST OF THE WEEK.

ALEUTIANS/BERING SEA...COLD AIR BEING PUSHED SOUTH UNDER THE DEEP
TROUGH IS LEADING TO 10 TO 15 DEGREE BELOW NORMAL TEMPERATURES FROM
THE MAINLAND COAST TO THE CENTRAL ALEUTIANS. TEMPERATURES WILL SLOWLY
WARM UP AS THE SOURCE OF THE COLD AIR IS SLOWLY PINCHED OFF AND
MODERATES. WEAK HIGH PRESSURE WILL PREVAIL OVER THE WESTERN ALEUTIANS
WITH LOW PRESSURE TO THE EAST. THIS PATTERN WILL CONTINUE THROUGH THE
WEEKEND.

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

AB APR 10