Gale Warning 520, NWS Anchorage, AK

534 
FZAK61 PAFC 051145
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 AM AKDT THU SEP 5 2013

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.

PKZ399-060300-
400 AM AKDT THU SEP 5 2013
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

HIGH PRESSURE WILL REMAIN OVER THE NORTHERN GULF THROUGH THIS
EVENING. A 998 MB LOW WILL MOVE TO 50N 153W THIS EVENING THEN TO 57N
152W FRI AFTERNOON AT 990 MB THEN MOVE INLAND TO THE NORTH.

$$

PKZ351-060300-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 AM AKDT THU SEP 5 2013

...GALE WARNING FRIDAY...

.TODAY...S WIND 10 TO 20 KT BECOMING E 15 KT IN THE AFTERNOON. 
SEAS 7 FT. 
.TONIGHT...E WIND 15 TO 25 KT. SEAS 8 FT. PATCHY FOG. RAIN.
.FRI...SE WIND 25 KT INCREASING TO 35 KT IN THE AFTERNOON. SEAS
BUILDING TO 15 FT. PATCHY FOG. 
.FRI NIGHT...S WIND 40 KT. SEAS BUILDING TO 20 FT. 
.SAT...SW WIND DIMINISHING TO 30 KT. SEAS SUBSIDING TO 14 FT. 
.SUN...S WIND 25 KT. SEAS SUBSIDING TO 9 FT. 
.MON...SE WIND 25 KT. SEAS 12 FT.  

$$

PKZ352-060300-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 AM AKDT THU SEP 5 2013

...GALE WARNING FRIDAY...

.TODAY...S WIND 15 KT BECOMING E WIND 20 KT IN THE AFTERNOON. SEAS 7
FT. PATCHY FOG. RAIN.
.TONIGHT...E WIND 20 KT BECOMING SE 20 TO 30 KT AFTER MIDNIGHT. SEAS
10 FT. PATCHY FOG. RAIN.
.FRI...S WIND 25 TO 35 KT INCREASING TO 45 KT IN THE AFTERNOON. SEAS
13 FT BUILDING TO 19 FT IN THE AFTERNOON. PATCHY FOG. 
.FRI NIGHT...SW WIND 40 KT. SEAS 20 FT. 
.SAT...W WIND DIMINISHING TO 25 KT. SEAS SUBSIDING TO 11 FT. 
.SUN THROUGH MON...S WIND 25 KT. SEAS 11 FT. 

$$

242 
FZAK61 PAFC 052330
OFFAER

OFFSHORE WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE AK
400 PM AKDT THU SEP 5 2013

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.

PKZ399-061500-
400 PM AKDT THU SEP 5 2013
.SYNOPSIS FOR THE WESTERN GULF OF ALASKA...

A 997 MB LOW AT 48N 154W WILL MOVE TO 55N 153W BY LATE FRI MORNING
AND DEEPEN TO 982 MB. THIS LOW WILL MOVE TO 58N 151W LATE FRI 
EVENING AT 992 MB THEN MOVE INLAND AND DISSIPATE SAT MORNING. A 999
MB LOW AT 52N 145W SAT MORNING WILL MOVE TO 56N 143W SAT AFTERNOON.

$$

PKZ351-061500-
GULF OF ALASKA OFFSHORE NORTH OF 57N AND WEST OF 144W
400 PM AKDT THU SEP 5 2013

...STORM WARNING FRIDAY NIGHT...

.TONIGHT...E WIND 30 KT...BECOMING SE TOWARDS MORNING. SEAS 9 FT.
PATCHY FOG. RAIN.
.FRI...SE WIND 45 KT. SEAS 12 FT BUILDING TO 18 FT IN THE AFTERNOON.
PATCHY FOG. 
.FRI NIGHT...SE WIND 50 KT BECOMING SW 40 KT AFTER MIDNIGHT. SEAS
24 FT. PATCHY FOG. 
.SAT...SW WIND 30 KT. SEAS 16 FT. 
.SAT NIGHT...NW WIND 15 KT. SEAS 7 FT. 
.SUN...SW WIND 25 KT. SEAS 9 FT. 
.MON AND TUE...SE WIND 25 KT. SEAS 12 FT.   

$$

PKZ352-061500-
GULF OF ALASKA OFFSHORE SOUTH OF 57N NORTH OF 55N AND WEST OF
144W
400 PM AKDT THU SEP 5 2013

...STORM WARNING FRIDAY AND FRIDAY NIGHT...

.TONIGHT...S TO E WIND 30 TO 40 KT. SEAS 10 FT. PATCHY FOG. RAIN.
.FRI...SE WIND 45 KT BECOMING S 55 KT IN THE AFTERNOON. SEAS 15 FT
BUILDING TO 23 FT IN THE AFTERNOON. 
.FRI NIGHT...S WIND 50 KT BECOMING SW 40 KT AFTER MIDNIGHT. SEAS
24 FT SUBSIDING TO 18 FT AFTER MIDNIGHT. PATCHY FOG. 
.SAT...SW WIND 25 KT. SEAS 13 FT. 
.SAT NIGHT...NW WIND 20 KT. SEAS 7 FT. 
.SUN AND MON...S WIND 25 KT. SEAS 12 FT.  
.TUE...SE WIND 20 KT. SEAS 13 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
200 PM AKDT WED SEP 4 2013

.ANALYSIS AND UPPER LEVELS...
THERE IS A LARGE UPPER LOW CENTERED JUST WEST OF BETHEL. CYCLONIC
FLOW COVERS MOST OF SOUTHERN ALASKA AND THE BERING SEA. A STRONG JET
(150+ KTS) IS OVER THE NORTH PACIFIC FROM KAMCHATKA SOUTHEAST TO
AROUND 40 DEGREES NORTH LATITUDE AND 155 DEGREES WEST LONGITUDE.
ANOTHER JET STRETCHES NORTHEAST FROM 40 NORTH TO NEAR YAKUTAT. A
SURFACE LOW IS JUST BEGINNING TO SPIN UP AT THE "INTERSECTION" (LEFT
EXIT/RIGHT ENTRANCE) OF THESE TWO JETS...FAIRLY OBVIOUS ON THE WATER
VAPOR SATELLITE IMAGERY AS A BAROCLINIC LEAF.

.MODEL DISCUSSION...
THE NUMERICAL MODELS ARE BASICALLY IN GOOD AGREEMENT THROUGH 84
HOURS. THE EXCEPTION IS THE NAM...WHICH BECOMES ANOMALOUS WITH A
DEVELOPING NORTH PACIFIC LOW AFTER 36 HOURS INTO THE FORECAST
(THURSDAY AFTERNOON). OTHERWISE THE MODELS ARE FAIRLY CLOSE WITH
JUST SOME MINOR TIMING/SPEED DIFFERENCES.

.SHORT TERM FORECAST...
FOR SOUTH CENTRAL AND SOUTHWEST ALASKA...THE ALASKAN UPPER LOW WILL
WEAKEN AND SPLIT OVER THE NEXT FEW DAYS AS MOST OF THE "ENERGY"
DIVES SOUTH INTO THE DEVELOPING NORTH PACIFIC LOW BETWEEN THE TWO
JETS. THIS LOW WILL MOVE INTO THE NORTHERN GULF THURSDAY NIGHT AND
INTO SOUTH CENTRAL ALASKA AND THE EASTERN PORTION OF SOUTHWEST
ALASKA ON FRIDAY. THIS LOW WILL THEN MOVE WELL INLAND ON SATURDAY
AND DISSIPATE AFTER LOOSING ITS UPPER LEVEL SUPPORT.

IN PRACTICAL WEATHER TERMS...SHOWERS WILL DIMINISH OVER SOUTH
CENTRAL ALASKA TONIGHT AND THURSDAY AND OVER SOUTHWEST ALASKA
THURSDAY AND THURSDAY NIGHT AS THE ALASKAN UPPER LOW DISSIPATES AND
HIGH PRESSURE BUILDS AHEAD OF THE NORTH PACIFIC LOW. WINDS AND RAIN
WILL INCREASE ON FRIDAY AS THE LOW MOVES INTO SOUTHERN ALASKA...THEN
CHANGE TO SHOWERS AND DECREASE ON SATURDAY AS THE LOW WEAKENS.

FOR THE BERING SEA AND ALEUTIANS...HIGH PRESSURE WILL BUILD OVER
THE BERING SEA ON FRIDAY AND SATURDAY FILLING THE VOID LEFT BY THE
FORMER ALASKA UPPER LOW. THE UPPER LEVEL STORM TRACK WILL REMAIN
OVER THE NORTHERN PACIFIC AND A WEATHER SYSTEM WILL MOVE INTO THE
WESTERN ALEUTIANS ON FRIDAY AND INTO THE CENTRAL ALEUTIANS ON
SATURDAY UNDERNEATH THE BERING SEA RIDGE...WITH THE SURFACE LOW
SLIDING EASTWARD JUST SOUTH OF THE ALEUTIANS.

.AER/ALU...WATCH/WARNING SUMMARY
PUBLIC...NONE.
MARINE...GALE WARNING 120 130 132 138 150.
FIRE WEATHER...NONE.

LUDWIG SEP 13

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1230 PM AKDT WED SEP 4 2013

AKZ181-050300

...MINOR ASH FALL POSSIBLE NEAR CHIGNIK AND PORT HEIDEN...

OBSERVED SEISMIC ACTIVITY INDICATES THAT VENIAMINOF VOLCANO CONTINUES
TO ERUPT WITH MINOR ASH EMISSIONS. WINDS ARE EXPECTED TO TRANSPORT
THE ASH TO THE EAST AND NORTHEAST...WHICH COULD RESULT IN SOME VERY
LIGHT ASHFALL EAST OF THE VOLCANO FROM CHIGNIK TO PORT HEIDEN THROUGH
THE AFTERNOON.

THIS STATEMENT WILL BE UPDATED BY 700 PM AKDT WEDNESDAY OR SOONER IF
CONDITIONS WARRANT.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE ANCHORAGE AK
1230 PM AKDT WED SEP 4 2013

AKZ181-050300-

...MINOR ASH FALL POSSIBLE NEAR CHIGNIK AND PORT HEIDEN...

OBSERVED SEISMIC ACTIVITY INDICATES THAT VENIAMINOF VOLCANO CONTINUES
TO ERUPT WITH MINOR ASH EMISSIONS. WINDS ARE EXPECTED TO TRANSPORT
THE ASH TO THE EAST AND NORTHEAST...WHICH COULD RESULT IN SOME VERY
LIGHT ASHFALL EAST OF THE VOLCANO FROM CHIGNIK TO PORT HEIDEN THROUGH
THE AFTERNOON.

THIS STATEMENT WILL BE UPDATED BY 700 PM AKDT WEDNESDAY OR SOONER IF
CONDITIONS WARRANT.