Small Craft Advisory 574, NWS Anchorage, AK

592 
FZAK51 PAFC 172047 AAA
CWFAER

COASTAL WATERS FORECAST...UPDATED
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
1245 PM AKDT WED AUG 17 2011

UPDATED ZONES 130 AND 140

COASTAL WATERS FORECAST FOR THE NORTHERN GULF OF ALASKA COAST
UP TO 100 NM OUT INCLUDING KODIAK ISLAND AND COOK INLET.

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.

PKZ197-180300-
400 AM AKDT WED AUG 17 2011
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...A RIDGE ALONG THE GULF COAST WILL CONTINUE TO BUILD
THROUGH THURSDAY. A WEATHER FRONT WILL MOVE INTO THE SOUTHERN GULF
THU AND REACH THE COAST BY THU NIGHT. 

$$

PKZ120-180300-
CAPE SUCKLING TO GORE POINT
400 AM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...SE WIND 20 KT. SEAS 5 FT. 
.TONIGHT...SE WIND 20 KT. SEAS 7 FT. 
.THU...E WIND 25 KT. SEAS 8 FT. RAIN.
.THU NIGHT...E WIND 35 KT. SEAS 14 FT. 
.FRI...E WIND 35 KT. SEAS 16 FT. 
.SAT...SE WIND 20 KT. SEAS 9 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 8 FT.  

$$

PKZ121-180300-
RESURRECTION BAY
400 AM AKDT WED AUG 17 2011

.TODAY...N WIND 10 KT BECOMING S IN THE AFTERNOON. SEAS 2 FT. 
.TONIGHT...VARIABLE WIND 10 KT BECOMING N AFTER MIDNIGHT. SEAS 2 FT.
HIGHER WINDS AND SEAS SOUTH OF CAINES HEAD.
.THU...N WIND 10 KT BECOMING S IN THE AFTERNOON. SEAS 2 FT. HIGHER
WINDS AND SEAS SOUTH OF CAINES HEAD. RAIN.
.THU NIGHT AND FRI...N WIND 20 KT. SEAS 4 FT. 
.SAT...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. 
.SUN...N WIND 10 KT. SEAS 2 FT.  

$$

PKZ125-180300-
PRINCE WILLIAM SOUND
400 AM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...E WIND 15 KT. SEAS 2 FT. PATCHY FOG. 
.TONIGHT...SE WIND 20 KT. SEAS 4 FT. 
.THU...E WIND 25 KT. SEAS 5 FT. RAIN SHOWERS. 
.THU NIGHT...E WIND 25 KT. SEAS 6 FT. 
.FRI...E WIND 30 KT. SEAS 7 FT. 
.SAT...E WIND 10 KT. SEAS 2 FT. 
.SUN...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT.  

$$

PKZ129-180300-
PASSAGE CANAL
400 AM AKDT WED AUG 17 2011

.TODAY...E WIND 10 KT. SEAS 2 FT. PATCHY FOG. RAIN SHOWERS. 
.TONIGHT...E WIND 15 KT. SEAS 2 FT. 
.THU...E WIND 20 KT. SEAS 3 FT. RAIN SHOWERS. 
.THU NIGHT AND FRI...E WIND 25 KT. SEAS 4 FT. 
.SAT...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 2 FT.  

$$

PKZ130-180300-
BARREN ISLANDS AND KAMISHAK BAY WATERS
1245 PM AKDT WED AUG 17 2011

...GALE WARNING THURSDAY...

.TODAY...W OF THE BARREN ISLANDS...S WIND 25 KT. SEAS 5 FT. 
E OF THE BARREN ISLANDS...SE WIND 15 KT. SEAS 3 FT. 
.TONIGHT...SE WIND 25 KT. SEAS 6 FT. 
.THU...E WIND 25 KT INCREASING TO 35 KT IN THE AFTERNOON. 
SEAS 6 FT BUILDING TO 10 FT. RAIN.
.THU NIGHT AND FRI...E WIND 35 KT. SEAS 13 FT. 
.SAT...VARIABLE WIND 10 KT. SEAS 7 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 6 FT.  

$$

PKZ132-180300-
SHUYAK ISLAND TO SITKINAK
400 AM AKDT WED AUG 17 2011

.TODAY...SW WIND 20 KT. SEAS 6 FT. 
.TONIGHT...S WIND 15 KT. SEAS 5 FT. 
.THU...SE WIND 15 KT. SEAS 6 FT. RAIN.
.THU NIGHT...SE WIND 20 KT. SEAS 6 FT. 
.FRI...S WIND 20 KT. SEAS 7 FT. 
.SAT...W WIND 20 KT. SEAS 8 FT. 
.SUN...W WIND 20 KT. SEAS 7 FT.  

$$

PKZ138-180300-
SHELIKOF STRAIT
400 AM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY THURSDAY...

.TODAY...SW WIND 10 KT INCREASING TO 20 KT LATER THIS MORNING. 
SEAS 3 FT BUILDING TO 6 FT IN THE AFTERNOON.
.TONIGHT...VARIABLE WIND 10 KT BECOMING E 15 KT AFTER MIDNIGHT. 
SEAS 2 FT. 
.THU...NE WIND 25 KT. SEAS 8 FT. RAIN.
.THU NIGHT...NE WIND 30 KT. SEAS 10 FT. 
.FRI...NE WIND 30 KT. SEAS 11 FT. 
.SAT...VARIABLE WIND 10 KT. SEAS 2 FT. 
.SUN...W WIND 15 KT. SEAS 2 FT.  

$$

PKZ140-180300-
COOK INLET NORTH OF KAMISHAK BAY AND ENGLISH BAY
1245 PM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY TODAY...

.TODAY...S WIND 15 KT INCREASING TO 25 KT BY LATE AFTERNOON. 
SEAS 2 FT BUILDING TO 5 FT IN THE AFTERNOON. 
.TONIGHT...SW WIND 20 KT BECOMING NE 15 KT AFTER MIDNIGHT. 
SEAS 5 FT.
.THU...NE WIND 20 KT. SEAS 4 FT BUILDING TO 7 FT IN THE AFTERNOON. 
N OF KALGIN ISLAND...SEAS 3 FT. 
.THU NIGHT...NE WIND 25 KT. SEAS 8 FT. 
.FRI...NE WIND 30 KT. SEAS 8 FT. 
.SAT AND SUN...S WIND 10 KT. SEAS 2 FT. 

$$

PKZ141-180300-
KACHEMAK BAY
400 AM AKDT WED AUG 17 2011

.TODAY...E WIND 10 KT BECOMING SW 10 KT IN THE AFTERNOON. 
SEAS 2 FT. 
.TONIGHT...NE WIND 10 KT. SEAS 2 FT. 
.THU...E WIND 10 KT INCREASING TO 20 KT IN THE AFTERNOON. 
SEAS 3 FT.
.THU NIGHT...E WIND 25 KT. SEAS 5 FT. 
.FRI...E WIND 25 KT. SEAS 4 FT. 
.SAT...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. 
.SUN...S WIND 10 KT. SEAS 3 FT.  

$$

498 
FZAK51 PAFC 172349
CWFAER

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
400 PM AKDT WED AUG 17 2011

COASTAL WATERS FORECAST FOR THE NORTHERN GULF OF ALASKA COAST
UP TO 100 NM OUT INCLUDING KODIAK ISLAND AND COOK INLET.

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.

PKZ197-181500-
400 PM AKDT WED AUG 17 2011
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...
A RIDGE ALONG THE NORTH GULF COAST WILL CONTINUE TO STRENGTHEN
THROUGH THU. A FRONT WILL MOVE ACROSS THE WESTERN GULF ON FRI. 
A 990 MB LOW WILL FROM NEAR KODIAK ISLAND FRI AFTERNOON.
$$

PKZ120-181500-
CAPE SUCKLING TO GORE POINT
400 PM AKDT WED AUG 17 2011

...GALE WARNING THURSDAY NIGHT...

.TONIGHT...SE WIND 20 KT. SEAS 5 FT. 
.THU...SE WIND 25 KT. SEAS 7 FT. RAIN.
.THU NIGHT...E WIND 35 KT. SEAS 9 FT. RAIN.
.FRI...E WIND 35 KT. SEAS 10 FT. 
.FRI NIGHT...SE WIND 30 KT. SEAS 9 FT. 
.SAT...SE WIND 20 KT. SEAS 10 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 8 FT. 
.MON...E WIND 15 KT. SEAS 6 FT.  

$$

PKZ121-181500-
RESURRECTION BAY
400 PM AKDT WED AUG 17 2011

.TONIGHT...S WIND 10 KT BECOMING N AFTER MIDNIGHT. SEAS 2 FT. 
.THU...N WIND 10 KT BECOMING S IN THE AFTERNOON. SEAS 2 FT. RAIN.
.THU NIGHT...VARIABLE WIND LESS THAN 10 KT BECOMING N 15 KT AFTER
MIDNIGHT. SEAS 3 FT. HIGHER WINDS AND SEAS S OF CAINES HEAD. RAIN.
.FRI AND FRI NIGHT...N WIND 15 KT. SEAS 3 FT.
.SAT...VARIABLE WIND 10 KT. SEAS 2 FT. 
.SUN...N WIND 10 KT. SEAS 2 FT. 
.MON...S WIND 10 KT. SEAS 2 FT.  

$$

PKZ125-181500-
PRINCE WILLIAM SOUND
400 PM AKDT WED AUG 17 2011

.TONIGHT...E WIND 15 KT. SEAS 3 FT. 
.THU...E WIND 20 KT. SEAS 4 FT. RAIN SHOWERS. 
.THU NIGHT...E WIND 20 KT. SEAS 4 FT. RAIN.
.FRI...NE WIND 20 KT. SEAS 4 FT. 
.FRI NIGHT...E WIND 20 KT. SEAS 4 FT. 
.SAT...E WIND 15 KT. SEAS 3 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 2 FT. 
.MON...NE WIND 10 KT. SEAS 2 FT.  

$$

PKZ129-181500-
PASSAGE CANAL
400 PM AKDT WED AUG 17 2011

.TONIGHT...E WIND 15 KT. SEAS 2 FT. 
.THU...E WIND 15 KT. SEAS 2 FT. RAIN SHOWERS. 
.THU NIGHT...E WIND 20 KT. SEAS 3 FT. RAIN.
.FRI AND FRI NIGHT...E WIND 20 KT. SEAS 3 FT. 
.SAT...E WIND 10 KT. SEAS 2 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 2 FT. 
.MON...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT.  

$$

PKZ130-181500-
BARREN ISLANDS AND KAMISHAK BAY WATERS
400 PM AKDT WED AUG 17 2011

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

.TONIGHT...SE WIND 25 KT. SEAS 6 FT. 
.THU...SE WIND 25 KT BECOMING E 35 KT IN THE AFTERNOON. SEAS 8 FT.
RAIN.
.THU NIGHT...NE WIND 35 KT. SEAS 9 FT. RAIN.
.FRI...E WIND 35 KT. SEAS 9 FT. 
.FRI NIGHT...SE WIND 25 KT. SEAS 8 FT. 
.SAT...SE WIND 15 KT. SEAS 8 FT. 
.SUN AND MON...VARIABLE WIND 10 KT. SEAS 5 FT.

$$

PKZ132-181500-
SHUYAK ISLAND TO SITKINAK
400 PM AKDT WED AUG 17 2011

.TONIGHT...S WIND 15 KT. SEAS 5 FT. RAIN.
.THU AND THU NIGHT...SE WIND 15 KT. SEAS 5 FT. RAIN.
.FRI...S WIND 20 KT. SEAS 7 FT. 
.FRI NIGHT AND SAT...SW WIND 20 KT. SEAS 8 FT. 
.SUN...W WIND 20 KT. SEAS 7 FT. 
.MON...N WIND 15 KT. SEAS 7 FT.  

$$

PKZ138-181500-
SHELIKOF STRAIT
400 PM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY THURSDAY AND THURSDAY NIGHT...

.TONIGHT...SW WIND 15 KT BECOMING NE 20 KT AFTER MIDNIGHT. SEAS 4 FT.

.THU...E WIND 25 KT. SEAS 5 FT. RAIN.
.THU NIGHT...NE WIND 30 KT. SEAS 8 FT. RAIN.
.FRI...E WIND 25 KT. SEAS 7 FT. 
.FRI NIGHT AND SAT...VARIABLE WIND 10 KT. SEAS 2 FT. 
.SUN...W WIND 15 KT. SEAS 2 FT. 
.MON...N WIND 15 KT. SEAS 2 FT.  

$$

PKZ140-181500-
COOK INLET NORTH OF KAMISHAK BAY AND ENGLISH BAY
400 PM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY TONIGHT AND THURSDAY NIGHT...

.TONIGHT...S WIND 15 KT...EXCEPT 25 KT DURING THE EVENING S OF KALGIN
ISLAND. SEAS 2 FT...EXCEPT 4 FT IN THE EVENING S OF KALGIN ISLAND. 
.THU...E WIND 10 KT BECOMING NE 20 KT IN THE AFTERNOON. SEAS 2 FT. 
.THU NIGHT...NE WIND 25 KT. SEAS 5 FT. RAIN.
.FRI...NE WIND 30 KT. SEAS 7 FT. 
.FRI NIGHT...NE WIND 25 KT. SEAS 6 FT. 
.SAT...SW WIND 10 KT. SEAS 2 FT. 
.SUN AND MON...S WIND 10 KT. SEAS 2 FT. 

$$

PKZ141-181500-
KACHEMAK BAY
400 PM AKDT WED AUG 17 2011

...SMALL CRAFT ADVISORY THURSDAY NIGHT...

.TONIGHT...SW WIND 15 KT BECOMING E 10 KT AFTER MIDNIGHT. SEAS 3 FT
SUBSIDING TO 1 FT. 
.THU...NE WIND 20 KT. SEAS 3 FT. 
.THU NIGHT...NE WIND 25 KT. SEAS 4 FT. RAIN.
.FRI...NE WIND 25 KT. SEAS 4 FT. 
.FRI NIGHT...NE WIND 15 KT. SEAS 3 FT. 
.SAT THROUGH MON...SW WIND 10 KT. SEAS 2 FT. 

$$

085 
FZAK51 PAFC 181110
CWFAER

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
400 AM AKDT THU AUG 18 2011

COASTAL WATERS FORECAST FOR THE NORTHERN GULF OF ALASKA COAST
UP TO 100 NM OUT INCLUDING KODIAK ISLAND AND COOK INLET.

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.

PKZ197-190300-
400 AM AKDT THU AUG 18 2011
.SYNOPSIS FOR THE NORTH GULF COAST+KODIAK ISLAND WATERS+
COOK INLET...A RIDGE ALONG THE NORTH GULF COAST WILL CONTINUE TO
STRENGTHEN THROUGH THU. A FRONT WILL MOVE ACROSS THE WESTERN GULF ON
FRI. A 984 MB LOW WILL FROM NEAR KODIAK ISLAND FRI AFTERNOON.

$$

PKZ120-190300-
CAPE SUCKLING TO GORE POINT
400 AM AKDT THU AUG 18 2011

...GALE WARNING TONIGHT AND FRIDAY...

.TODAY...SE WIND INCREASING TO 20 KT THIS MORNING. WINDS BECOMING E
30 KT IN THE AFTERNOON. SEAS 6 FT BUILDING TO 11 FT IN THE AFTERNOON.
RAIN.
.TONIGHT...E WIND 40 KT. SEAS 14 FT. RAIN.
.FRI...E WIND 35 KT. SEAS 14 FT. RAIN.
.FRI NIGHT...SE WIND 35 KT. SEAS 10 FT. 
.SAT...SE WIND 25 KT. SEAS 11 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 8 FT. 
.MON...VARIABLE WIND 10 KT. SEAS 6 FT.  

$$

PKZ121-190300-
RESURRECTION BAY
400 AM AKDT THU AUG 18 2011

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...N WIND 15 KT BECOMING S 10 KT IN THE AFTERNOON. SEAS 3 FT.
HIGHER WINDS AND SEAS S OF CAINES HEAD. RAIN.
.TONIGHT...N WIND 15 KT INCREASING TO 25 KT AFTER MIDNIGHT. SEAS 2 FT
BUILDING TO 5 FT AFTER MIDNIGHT. HIGHER WINDS AND SEAS S OF CAINES
HEAD. RAIN.
.FRI...N WIND 25 KT DIMINISHING TO 15 KT IN THE AFTERNOON. SEAS 5 FT
SUBSIDING TO 3 FT IN THE AFTERNOON. HIGHER WINDS AND SEAS S OF
CAINES HEAD. RAIN.
.FRI NIGHT...N WIND 15 KT. SEAS 3 FT. 
.SAT...VARIABLE WIND 15 KT. SEAS 3 FT. 
.SUN...N WIND 10 KT. SEAS 2 FT. 
.MON...VARIABLE WIND 10 KT. SEAS 2 FT.  

$$

PKZ125-190300-
PRINCE WILLIAM SOUND
400 AM AKDT THU AUG 18 2011

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...E WIND 20 KT. SEAS 4 FT. RAIN SHOWERS. 
.TONIGHT...E WIND 30 KT. SEAS 7 FT. RAIN.
.FRI...NE WIND 25 KT. SEAS 4 FT. RAIN.
.FRI NIGHT...E WIND 25 KT. SEAS 4 FT. 
.SAT...E WIND 20 KT. SEAS 3 FT. 
.SUN AND MON...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. 

$$

PKZ129-190300-
PASSAGE CANAL
400 AM AKDT THU AUG 18 2011

...SMALL CRAFT ADVISORY TONIGHT AND FRIDAY...

.TODAY...E WIND 20 KT. SEAS 3 FT. RAIN SHOWERS. 
.TONIGHT AND FRI...E WIND 25 KT. SEAS 4 FT. RAIN.
.FRI NIGHT...E WIND 20 KT. SEAS 2 FT. 
.SAT...E WIND 15 KT. SEAS 2 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 2 FT. 
.MON...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT.  

$$

PKZ130-190300-
BARREN ISLANDS AND KAMISHAK BAY WATERS
400 AM AKDT THU AUG 18 2011

...GALE WARNING THROUGH FRIDAY...

.TODAY...SE 25 KT INCREASING TO NE 35 KT BY AFTERNOON. SEAS 5 FT
BUILDING TO 9 FT BY AFTERNOON. RAIN.
.TONIGHT...NE WIND 35 KT. SEAS 11 FT. RAIN.
.FRI...E WIND 40 KT. SEAS 13 FT. RAIN.
.FRI NIGHT...SE WIND 30 KT. SEAS 9 FT. 
.SAT...SE WIND 20 KT. SEAS 10 FT. 
.SUN...VARIABLE WIND 10 KT. SEAS 6 FT. 
.MON...W WIND 15 KT. SEAS 5 FT.  

$$

PKZ132-190300-
SHUYAK ISLAND TO SITKINAK
400 AM AKDT THU AUG 18 2011

...SMALL CRAFT ADVISORY FRIDAY...

.TODAY...SE WIND 15 KT. SEAS 5 FT. RAIN.
.TONIGHT...SE WIND 20 KT. SEAS 7 FT. RAIN.
.FRI...SW WIND 25 KT. SEAS 8 FT. RAIN.
.FRI NIGHT...SW WIND 25 KT. SEAS 10 FT. 
.SAT...W WIND 20 KT. SEAS 10 FT. 
.SUN...W WIND 20 KT. SEAS 8 FT. 
.MON...NW WIND 20 KT. SEAS 6 FT.  

$$

PKZ138-190300-
SHELIKOF STRAIT
400 AM AKDT THU AUG 18 2011

...GALE WARNING FRIDAY...

.TODAY...NE WIND 25 KT. SEAS 6 FT BUILDING TO 9 FT. RAIN.
.TONIGHT...NE WIND 30 KT. SEAS 10 FT. RAIN.
.FRI...NE WIND 35 KT. SEAS 11 FT. RAIN.
.FRI NIGHT...W WIND 20 KT. SEAS 3 FT. 
.SAT...VARIABLE WIND 10 KT. SEAS 2 FT. 
.SUN...W WIND 15 KT. SEAS 3 FT. 
.MON...W WIND 15 KT. SEAS 2 FT.  

$$

PKZ140-190300-
COOK INLET NORTH OF KAMISHAK BAY AND ENGLISH BAY
400 AM AKDT THU AUG 18 2011

...GALE WARNING FRIDAY...

.TODAY...NE WIND 15 KT INCREASING TO 25 KT IN THE AFTERNOON. SEAS
3 FT BUILDING TO 7 FT IN THE AFTERNOON. 
.TONIGHT...NE WIND 30 KT. SEAS 7 FT. RAIN.
.FRI...NE WIND 40 KT EXCEPT NE 25 KT N OF KALGIN ISLAND. SEAS 11 FT
EXCEPT 6 FT N OF KALGIN ISLAND. RAIN.
.FRI NIGHT...NE WIND 30 KT. SEAS 7 FT. 
.SAT...N WIND 25 KT. SEAS 6 FT. 
.SUN...S WIND 10 KT. SEAS 2 FT. 
.MON...SW WIND 10 KT. SEAS 2 FT.  

$$

PKZ141-190300-
KACHEMAK BAY
400 AM AKDT THU AUG 18 2011

...SMALL CRAFT ADVISORY THROUGH FRIDAY...

.TODAY...E WIND 15 KT INCREASING TO 25 KT IN THE AFTERNOON. SEAS
2 FT BUILDING TO 4 FT. 
.TONIGHT...E WIND 25 KT. SEAS 5 FT. RAIN.
.FRI...NE WIND 25 KT. SEAS 4 FT. RAIN.
.FRI NIGHT...NE WIND 20 KT. SEAS 3 FT. 
.SAT...S WIND 15 KT. SEAS 2 FT. 
.SUN...S WIND 10 KT. SEAS 2 FT. 
.MON...SW WIND 10 KT. SEAS 3 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
1245 PM AKDT TUE AUG 16 2011

.ANALYSIS AND UPPER LEVELS...CONSIDERING A TROUGH IS SITTING RIGHT
OVER MAINLAND ALASKA CONDITIONS ARE QUITE NICE AT THE MOMENT. A
CLOSER LOOK SHOWS AN UPPER LOW EXITING INTO THE YUKON WITH VERY
WEAK RIDGING BEHIND OVER WESTERN SOUTHCENTRAL ALASKA WHERE MOSTLY
CLEAR SKIES DOMINATE. THE 12Z ANCHORAGE SOUNDING SHOWS A DEEP LAYER
OF INSTABILITY ABOVE 4000 FEET. THIS IS REPRESENTATIVE OF THE AIR
MASS ACROSS SOUTHCENTRAL...SO AFTERNOON HEATING WILL HELP REALIZE
SOME OF THIS CONVECTIVE POTENTIAL. WATER VAPOR IMAGERY SHOWS A
COUPLE WEAK SHORT-WAVES MOVING DOWN THE BACK SIDE OF THE TROUGH...
ONE OVER INTERIOR SOUTHWEST ALASKA AND ANOTHER OVER THE FAR NORTHERN
BERING SEA. BOTH OF THESE WILL AID IN CONVECTIVE INITIATION THIS
AFTERNOON AND EVENING. THERE ARE ALSO A COUPLE WEAK WAVES ON THE
BACK SIDE OF THE UPPER LOW ROTATING THROUGH THE COPPER RIVER BASIN.
IN FACT CUMULUS CLOUDS ARE ALREADY POPPING UP ACROSS THE MOUNTAINS
SURROUNDING THE COPPER BASIN IN RESPONSE TO ONE OF THESE WAVES.

A RIDGE IS SITTING TO THE WEST OVER THE CENTRAL BERING WITH A
TROUGH SOUTH OF THE CENTRAL AND EASTERN ALEUTIANS. MOST OF THE
MOISTURE WITH THIS TROUGH IS JUST SOUTH OF THE CHAIN. A DEEPENING
LOW EAST OF THE KAMCHATKA PENINSULA IS PUSHING A FRONT TOWARD THE
WESTERN ALEUTIANS AND CAUSING THE DOWNSTREAM RIDGE TO GRADUALLY
WEAKEN.

.MODEL DISCUSSION...MODEL CONSISTENCY REMAINS POOR WITH HANDLING
OF LOW MOVING ACROSS THE BERING SEA WEDNESDAY NIGHT THROUGH FRIDAY.
THE ROOT OF THE PROBLEM WITH TRACK OF THE SURFACE LOW STEMS FROM
THE COMPLEXITY OF THE UPPER LEVEL PATTERN. AS TROUGH MOVES INTO
THE BERING SEA MODELS INDICATE MULTIPLE STRONG WAVES MOVING THROUGH
IT WHICH WILL AFFECT WHERE THE MAIN UPPER CENTER SETS UP AND THUS
WHERE TH SURFACE LOW WILL TRACK TO. LOOKS LIKE IT MAY TAKE ANOTHER
FEW MODEL CYCLES BEFORE THEY CAN RESOLVE THESE FEATURES CORRECTLY.
WILL STICK CLOSE TO THE EXISTING FORECAST WHICH IS CLOSEST TO THE
NAM SOLUTION. ASIDE FROM HANDLING OF THIS SYSTEM...MODELS ARE IN
GOOD AGREEMENT THROUGH THE NEXT FEW DAYS.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...UNSTABLE AIR MASS IN PLACE COMBINED WITH
FORCING FROM UPPER LEVEL WAVES WILL PRODUCE ISOLATED TO SCATTERED
CONVECTION ACROSS SOUTHCENTRAL THIS AFTERNOON. SUBSIDENCE FROM THE
WEAK RIDGE MOVING THROUGH MAY LOCALLY CAP CONVECTION ESPECIALLY
OVER VALLEYS. MODEL STABILITY INDICES FOR THIS AFTERNOON/EVENING
SUPPORT DEVELOPMENT OF ISOLATED THUNDERSTORMS...PRIMARILY THE
TYPICALLY FAVORED MORE UNSTABLE AREAS INLAND AND ALONG THE MOUNTAINS.
STORM MOTION WILL ALSO BE KEY TO WHERE CONVECTION IS OBSERVED.
THE MEAN FLOW IS OUT OF THE NORTH THIS MORNING BUT WILL BECOME
MORE WESTERLY THIS AFTERNOON AS SHORT-WAVE MOVES IN FROM SOUTHWEST
ALASKA. THIS MEANS CONVECTION THAT FORMS ALONG THE CHUGACH WILL MOVE
AWAY FROM ANCHORAGE AND MORE STABLE AIR WILL LIKELY MOVE IN OFF THE
INLET. BASED ON THIS REASONING...ACTIVITY FROM THE KENAI PENINSULA
TO ANCHORAGE WILL LIKELY BE CONFINED TO RIGHT ALONG AND OVER THE
MOUNTAINS.

THE NEXT SHORT-WAVE CURRENTLY OVER THE NORTHERN BERING WILL DIG
SOUTHWARD AS IT REACHES SOUTHCENTRAL EARLY WEDNESDAY MORNING. THIS
WILL RESULT IN MORE CLOUDS AND STABILIZATION OF THE AIR MASS. THERE
WILL STILL BE ENOUGH MID TO UPPER LEVEL INSTABILITY FOR PRECIPITATION
TO TAKE THE FORM OF SHOWERS. AN ISOLATED THUNDERSTORM OR TWO IS STILL
POSSIBLE INLAND MAINLY OVER THE COPPER RIVER BASIN WHICH WILL SEE
SOME SUNSHINE BEFORE CLOUDS INCREASE. BASED ON THE SHARPNESS OF THIS
SHORT-WAVE PLAN TO INCREASE POPS...ESPECIALLY FROM THE WESTERN KENAI
PENINSULA TO THE SUSITNA VALLEY. THE SHORT-WAVE TROUGH WILL STALL
OVER SOUTHCENTRAL WEDNESDAY NIGHT AND THURSDAY...GRADUALLY ELONGATING
AND WEAKENING. THUS SHOWERS WILL DIMINISH WITH TIME. ON THURSDAY A
FRONTAL SYSTEM EXTENDING FROM A BERING SEA LOW WILL MAKE ITS WAY
TOWARD SOUTHCENTRAL. THERE IS UNCERTAINTY IN THE EXACT TIMING AND
STRENGTH OF THIS FRONT...BUT EXPECT RAIN TO AFFECT THE REGION LATE
THURSDAY THROUGH FRIDAY TIME FRAME.

SOUTHWEST ALASKA...THE SHORT-WAVE OVER THE NORTHERN BERING WILL HELP
TRIGGER SCATTERED SHOWERS AND POSSIBLY A FEW THUNDERSTORMS THIS
AFTERNOON AND EVENING OVER INTERIOR SOUTHWEST ALASKA. IT WILL THEN
STALL OVERHEAD OF THE KUSKOKWIM VALLEY AND PROVIDE A CHANCE OF
SHOWERS THROUGH WEDNESDAY. MEANWHILE...THE BERING RIDGE WILL SHIFT
EASTWARD TOWARD SOUTHWEST ALASKA AND PROVIDE DRY WEATHER UNTIL THE
INTENSIFYING STORM SYSTEM REACHES THE COAST SOME TIME ON THURSDAY.
ALTHOUGH THERE IS SOME UNCERTAINTY WITH THIS STORM IT APPEARS LIKELY
THAT ALL OF SOUTHWEST ALASKA WILL SEE RAIN AND WIND AT THE END OF
THE WEEK.

BERING SEA/ALEUTIANS...THE FRONT ENTERING THE WESTERN ALEUTIANS
WILL RAPIDLY WEAKEN AS IT PROGRESSES EASTWARD. HOWEVER...EXPECT
RAPID DEVELOPMENT OF A LOW TRACKING ACROSS THE BERING SEA WEDNESDAY
NIGHT THROUGH THURSDAY NIGHT. THERE IS QUITE A BIT OF UNCERTAINTY
IN THE EXACT TRACK OF THE LOW...BUT EXPECT IMPACTS TO BE WIDESPREAD
THROUGH THE END OF THE WEEK.

.LONG TERM FORECAST...GFS/ECWMF SHOW EXCELLENT AGREEMENT WITH BASIC
EVOLUTION OF LONG-WAVE PATTERN THROUGH MOST OF THE DAY 4 THROUGH 7
PERIOD. THE LARGE LOW OVER THE EASTERN BERING WILL MOVE INTO THE
GULF OVER THE WEEKEND LIKELY PROVIDING A FAIRLY WET WEEKEND ACROSS
THE SOUTHERN MAINLAND. A RIDGE WILL BUILD IN BEHIND IT ACROSS THE
BERING SEA AND ALEUTIANS BRINGING A RETURN TO BENIGN CONDITIONS.
THE OTHER FEATURE WHICH MAY AFFECT THE SOUTHERN MAINLAND BY EARLY
NEXT WEEK IS A LARGE LOW OVER THE ARCTIC...ALTHOUGH MODEL SPREAD
WITH SHORT-WAVES ROTATING AROUND THIS IS FAIRLY LARGE.

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

SEB AUG 11