Small Craft Advisory 566, NWS Anchorage, AK

786 
FZAK52 PAFC 132237
CWFALU

COASTAL WATERS FORECAST
NATIONAL WEATHER SERVICE ANCHORAGE ALASKA
400 PM AKDT SAT AUG 13 2011

COASTAL WATERS FORECAST FOR SOUTHWEST ALASKA+BRISTOL BAY+THE
ALASKA PENINSULA WATERS AND THE ALEUTIAN ISLANDS UP TO 100 NM OUT.

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.

PKZ199-141500-
400 PM AKDT SAT AUG 13 2011
.SYNOPSIS FOR SOUTHWEST ALASKA+BRISTOL BAY+THE ALASKA
PENINSULA WATERS AND THE ALEUTIAN ISLANDS...
HIGH PRESSURE WILL PERSIST OVER THE EASTERN BERING THROUGH SUNDAY
EVENING. A 1002 MB LOW 260 NM SOUTH OF SHEMYA WILL MOVE NEAR SHEMYA
SUNDAY AFTERNOON AND DISSIPATE. A NORTH PACIFIC LOW WILL MOVE TO 
85 NM SOUTHEAST OF ATKA MONDAY AFTERNOON. 
$$

PKZ150-141500-
COASTAL WATERS SOUTH OF THE ALASKA PENINSULA SITKINAK TO CASTLE
CAPE
400 PM AKDT SAT AUG 13 2011

...SMALL CRAFT ADVISORY THROUGH SUNDAY...

.TONIGHT...NW WIND 25 KT. SEAS 6 FT. 
.SUN...NW WIND 25 KT. SEAS 6 FT. 
.SUN NIGHT...NW WIND 20 KT. SEAS 6 FT. 
.MON...W WIND 20 KT. SEAS 5 FT. 
.MON NIGHT...SW WIND 15 KT. SEAS 5 FT. 
.TUE...VARIABLE WIND 10 KT. SEAS 5 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 4 FT. 
.THU...S WIND 20 KT. SEAS 4 FT.  

$$

PKZ155-141500-
COASTAL WATERS SOUTH OF THE ALASKA PENINSULA CASTLE CAPE TO CAPE
SARICHEF
400 PM AKDT SAT AUG 13 2011

.TONIGHT...NW WIND 20 KT. SEAS 5 FT. PATCHY FOG.
.SUN...NW WIND 20 KT. SEAS 5 FT. PATCHY FOG. 
.SUN NIGHT...W WIND 15 KT. SEAS 4 FT. 
.MON...SW WIND 15 KT. SEAS 5 FT. 
.MON NIGHT...SE WIND 15 KT. SEAS 6 FT. 
.TUE...VARIABLE WIND 10 KT. SEAS 5 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 4 FT. 
.THU...S WIND 20 KT. SEAS 6 FT.  

$$

PKZ160-141500-
BRISTOL BAY WATERS CAPE NEWENHAM TO PORT HEIDEN
400 PM AKDT SAT AUG 13 2011


.TONIGHT...NW WIND 20 KT. SEAS 6 FT. DENSE FOG. 
.SUN...NW WIND 20 KT. SEAS 6 FT. DENSE FOG. 
.SUN NIGHT...W WIND 20 KT. SEAS 5 FT. PATCHY FOG. 
.MON...W WIND 20 KT. SEAS 4 FT. 
.MON NIGHT...W WIND 10 KT. SEAS 2 FT. 
.TUE...N WIND 10 KT. SEAS 2 FT. 
.WED...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. 
.THU...SE WIND 15 KT. SEAS 3 FT.  

$$

PKZ165-141500-
PORT HEIDEN TO CAPE SARICHEF
400 PM AKDT SAT AUG 13 2011

.TONIGHT...NW WIND 20 KT. SEAS 4 FT. DENSE FOG. 
.SUN...NW WIND 15 KT. SEAS 4 FT. DENSE FOG. 
.SUN NIGHT...NW WIND 15 KT BECOMING SW AFTER MIDNIGHT. SEAS 3 FT.
AREAS OF FOG. 
.MON...VARIABLE WIND 10 KT. SEAS 3 FT. 
.MON NIGHT...VARIABLE WIND 10 KT. SEAS 2 FT. 
.TUE...VARIABLE WIND 10 KT. SEAS 2 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 2 FT. 
.THU...S WIND 20 KT. SEAS 4 FT.  

$$

PKZ180-141500-
SOUTHWEST ALASKA WATERS CAPE NEWENHAM TO DALL POINT
400 PM AKDT SAT AUG 13 2011

.TONIGHT...W WIND 20 KT. SEAS 6 FT. DENSE FOG. 
.SUN...W WIND 20 KT. SEAS 5 FT. DENSE FOG. RAIN.
.SUN NIGHT...W WIND 15 KT. SEAS 4 FT. PATCHY FOG. RAIN.
.MON...N WIND 15 KT. SEAS 4 FT. 
.MON NIGHT...N WIND 15 KT. SEAS 4 FT. 
.TUE...N WIND 15 KT. SEAS 4 FT. 
.WED...SE WIND 15 KT. SEAS 5 FT. 
.THU...SE WIND 15 KT. SEAS 4 FT.  

$$

PKZ170-141500-
EASTERN ALEUTIANS CAPE SARICHEF TO NIKOLSKI
400 PM AKDT SAT AUG 13 2011

.TONIGHT...VARIABLE WIND 10 KT. SEAS 4 FT. DENSE FOG. 
.SUN...E WIND 15 KT. SEAS 4 FT. DENSE FOG. 
.SUN NIGHT...E WIND 20 KT. SEAS 6 FT. PATCHY FOG. 
.MON...E WIND 20 KT. SEAS 8 FT. 
.MON NIGHT...E WIND 15 KT. SEAS 6 FT. 
.TUE...NE WIND 15 KT. SEAS 6 FT. 
.WED...VARIABLE WIND 10 KT. SEAS 4 FT. 
.THU...SW WIND 20 KT. SEAS 7 FT.  

$$

PKZ171-141500-
UNALASKA BAY
400 PM AKDT SAT AUG 13 2011

.TONIGHT...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. AREAS OF FOG.
.SUN...VARIABLE WIND LESS THAN 10 KT. SEAS 2 FT. AREAS OF FOG. 
.SUN NIGHT...SE WIND 10 KT INCREASING TO 15 KT AFTER MIDNIGHT. SEAS
2 FT. AREAS OF FOG. 
.MON...SE WIND 15 KT. SEAS 2 FT. 
.MON NIGHT...E WIND 10 KT. SEAS 2 FT. 
.TUE...NE WIND 10 KT. SEAS 2 FT. 
.WED...S WIND 10 KT. SEAS 2 FT. 
.THU...S WIND 15 KT. SEAS 2 FT.  

$$

PKZ172-141500-
EASTERN ALEUTIANS NIKOLSKI TO ADAK
400 PM AKDT SAT AUG 13 2011

...SMALL CRAFT ADVISORY SUNDAY AND SUNDAY NIGHT...

.TONIGHT...SE WIND 20 KT. SEAS 7 FT. DENSE FOG. 
.SUN...E WIND 25 KT. SEAS 8 FT. PATCHY DENSE FOG. RAIN.
.SUN NIGHT...E WIND 25 KT. SEAS 10 FT. PATCHY FOG. RAIN.
.MON...NE WIND 20 KT. SEAS 9 FT. 
.MON NIGHT...NE WIND 20 KT. SEAS 7 FT. 
.TUE...E WIND 15 KT. SEAS 6 FT. 
.WED...S WIND 15 KT. SEAS 6 FT. 
.THU...SW WIND 20 KT. SEAS 8 FT.  

$$

PKZ175-141500-
WESTERN ALEUTIANS ADAK TO KISKA
400 PM AKDT SAT AUG 13 2011

...SMALL CRAFT ADVISORY THROUGH SUNDAY NIGHT...

.TONIGHT...SE WIND 25 KT. SEAS 9 FT. DENSE FOG.
.SUN...SE WIND 25 KT. SEAS 8 FT. PATCHY FOG. RAIN.
.SUN NIGHT...E WIND 15 KT. SEAS 9 FT. PATCHY FOG. RAIN.
.MON...NE WIND 15 KT. SEAS 8 FT. 
.MON NIGHT...N WIND 15 KT. SEAS 6 FT. 
.TUE...S WIND 25 KT. SEAS 6 FT. 
.WED...SW WIND 20 KT. SEAS 8 FT. 
.THU...W WIND 20 KT. SEAS 7 FT.  

$$

PKZ176-141500-
WESTERN ALEUTIANS KISKA TO ATTU
400 PM AKDT SAT AUG 13 2011

...SMALL CRAFT ADVISORY THROUGH SUNDAY...

.TONIGHT...E WIND 25 KT. SEAS 9 FT. DENSE FOG.
.SUN...SE WIND 20 KT. SEAS 9 FT. DENSE FOG. RAIN SHOWERS.
.SUN NIGHT...SE WIND 15 KT. SEAS 7 FT. AREAS OF FOG. 
.MON...VARIABLE WIND 10 KT. SEAS 6 FT. 
.MON NIGHT...S WIND 20 KT. SEAS 6 FT. 
.TUE...SW WIND 30 KT. SEAS 10 FT. 
.WED...SW WIND 20 KT. SEAS 9 FT. 
.THU...NW WIND 15 KT. SEAS 5 FT.  

$$

PKZ185-141500-
ST MATTHEW ISLAND WATERS
400 PM AKDT SAT AUG 13 2011

.TONIGHT...SW WIND 20 KT. SEAS 7 FT. DENSE FOG. 
.SUN...SW WIND 15 KT. SEAS 6 FT. DENSE FOG. SHOWERS.
.SUN NIGHT...N WIND 20 KT. SEAS 5 FT. PATCHY FOG. RAIN.
.MON...NE WIND 20 KT. SEAS 5 FT. 
.MON NIGHT...NE WIND 20 KT. SEAS 5 FT. 
.TUE...E WIND 25 KT. SEAS 7 FT. 
.WED...SE WIND 25 KT. SEAS 7 FT. 
.THU...E WIND 20 KT. SEAS 4 FT.  

$$

PKZ179-141500-
PRIBILOF ISLANDS NEAR-SHORE WATERS
400 PM AKDT SAT AUG 13 2011

.TONIGHT...VARIABLE WIND 10 KT. SEAS 3 FT. DENSE FOG. 
.SUN...VARIABLE WIND 10 KT. SEAS 3 FT. DENSE FOG. 
.SUN NIGHT...VARIABLE WIND 10 KT. SEAS 3 FT. AREAS OF FOG. 
.MON...VARIABLE WIND 10 KT. SEAS 2 FT. 
.MON NIGHT...NE WIND 15 KT. SEAS 4 FT. 
.TUE...E WIND 15 KT. SEAS 4 FT. 
.WED...S WIND 15 KT. SEAS 4 FT. 
.THU...SE WIND 20 KT. SEAS 5 FT.  

$$

SOUTHCENTRAL AND SOUTHWEST ALASKA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ANCHORAGE AK
1220 PM AKDT FRI AUG 12 2011

.ANALYSIS AND UPPER LEVELS...A STRONG BLOCKING RIDGE IS STATIONARY
OVER THE EASTERN BERING SEA. THE RIDGE HAS BEEN BUILDING NORTHWARD
THE PAST COUPLE DAYS SO THAT PACIFIC MOISTURE WHICH HAD BEEN MOVING
OVER TOP OF THE RIDGE ACROSS THE CENTRAL BERING SEA NOW MUST HEAD
FARTHER NORTH TOWARD SIBERIA BEFORE HEADING EASTWARD TO THE ALASKA
MAINLAND. SHOWERS ARE MOVING ACROSS SOUTHWEST ALASKA THIS MORNING
ALONG THE EAST SIDE OF THE RIDGE AND DISSIPATING AS THEY CROSS THE
ALASKA AND ALEUTIAN RANGES. FURTHER EAST OVER SOUTHCENTRAL ALASKA
SUNNY SKIES ARE DOMINATING ONCE AGAIN. CHANGES ARE IN STORE THOUGH
AS THE RIDGE BUILDS EASTWARD A BIT PUSHING THAT MOISTURE OVER
SOUTHWEST ALASKA TOWARD SOUTHCENTRAL. ALSO OF NOTE IS AN UPPER LOW
NORTH OF THE BERING STRAIT WHICH IS POISED TO DROP SOUTHEASTWARD
AS THE BERING RIDGE NOSES ITS WAY UP INTO SIBERIA. UNDER THE RIDGE
AND TO THE WEST STRATUS AND AREAS OF DENSE FOG ARE THE NORM WITH
STEEP SURFACE BASED INVERSIONS IN PLACE TO MAINTAIN A VERY MOIST
BOUNDARY LAYER.

.MODEL DISCUSSION...MODELS HAVE COME INTO MUCH BETTER AGREEMENT
ON UPPER LOW DROPPING DOWN ACROSS THE MAINLAND AND INTO SOUTHCENTRAL
ON SUNDAY. THE FORECAST TONIGHT AND SATURDAY OVER SOUTHCENTRAL IS
A LITTLE TRICKIER AS RIDGE BEGINS TO BREAK DOWN AND MOISTURE MOVES
IN FROM SOUTHWEST ALASKA. MODELS DIFFER IN DEPTH OF MOISTURE/LIFT
OVER SOUTHCENTRAL AND THE RESULTANT QPF FIELDS ARE ALL OVER THE
PLACE. WITH ANTICYCLONIC CURVATURE ALOFT THINK ANY SHOWERS MOVING
IN FROM SOUTHWEST ALASKA WILL BEGIN TO DISSIPATE SO THAT ANYTHING
THAT DOES FALL WILL BE SPOTTY AND SHORT-LIVED. CHANCES WILL THEN
INCREASE DURING THE DAY SATURDAY AS THE RIDGE CONTINUES TO WEAKEN.
EVEN THEN...MODELS DON'T DEPICT ANY ORGANIZED FORCING MECHANISM SO
SHOWERS SHOULD NOT BE WIDESPREAD. BASICALLY...THIS MEANS DO NOT
FAVOR ANY PARTICULAR MODEL FOR PRECIPITATION FORECASTS. WILL USE
A MORE GENERAL BROAD-BRUSH PHILOSOPHY TONIGHT AND TOMORROW. AT THE
SURFACE PREFER THE NAM/EC/UKMET SOLUTION WITH POSITION OF LOW THAT
FORMS OVER THE NORTHERN GULF SUNDAY OUT AHEAD OF THE UPPER LOW.

OUT WEST...THERE ARE MINOR DIFFERENCES IN HANDLING OF WEAK LOWS
MOVING UP THE WEST SIDE OF THE RIDGE AND ALONG THE ALEUTIANS...BUT
NOT ENOUGH TO IMPACT THE SENSIBLE WEATHER FORECAST.

.SHORT TERM FORECAST...

SOUTHCENTRAL ALASKA...CLOUDS WILL BE ON THE INCREASE TONIGHT INTO
SATURDAY ACROSS THE REGION...BUT INITIALLY EXPECT NO MORE THAN A
FEW SHOWERS. THIS WILL CHANGE SATURDAY NIGHT AND SUNDAY AS UPPER
LOW DROPS DOWN FROM THE NORTH AND SURFACE TROUGH DEVELOPS FROM THE
KENAI PENINSULA TO COPPER RIVER BASIN. THIS WILL PRODUCE FAIRLY
WIDESPREAD RAIN ACROSS THE REGION. STEADY RAIN WILL CHANGE TO A
SHOWERS BY MONDAY AS THE UPPER LOW MOVES INTO THE NORTHERN GULF.
THERE WILL BE SOME MARGINAL IMPROVEMENT TUESDAY OVER MOST OF
SOUTHCENTRAL AS THE MAIN LOW CENTER ROTATES UP TOWARD THE YUKON.
HOWEVER...CLOUDS AND SHOWERS WILL REMAIN A THREAT WITH A BROAD
UPPER TROUGH SITTING OVER MAINLAND ALASKA.

SOUTHWEST ALASKA...ONE BATCH OF SHOWERS WILL EXIT THE REGION THIS
AFTERNOON LEAVING JUST A FEW ISOLATED SHOWERS BEHIND. HOWEVER...
INFLUENCE OF UPPER LOW DROPPING DOWN FROM NORTH WILL MEANS RAIN
OR SHOWERS WILL REDEVELOP ON SATURDAY...ESPECIALLY INLAND. ONSHORE
FLOW WILL MAINTAIN A VERY MOIST BOUNDARY LAYER SO FOG AND STRATUS
WILL CONTINUE TO PLAGUE COASTAL AREAS. CONDITIONS WILL IMPROVE
SUNDAY AND MONDAY ON THE BACK SIDE OF THE LOW WITH FLOW VEERING
TOWARD THE NORTH.

BERING SEA/ALEUTIANS...AS THE UPPER LOW DROPS SOUTHWARD ACROSS
MAINLAND ALASKA THIS WEEKEND THE BERING RIDGE WILL BE PUSHED
SOUTHWARD WITH JUST A WEAK REMNANT LEFT BY EARLY NEXT WEEK. THIS
WILL ALLOW COOLER AIR ALOFT TO FILTER SOUTHWARD AND RESULT IN MORE
UNSTABLE CONDITIONS WHICH WILL HELP BREAK UP SOME OF THE FOG. WEST
OF THE RIDGE...A COMBINATION OF WEAK LOWS MOVING THROUGH ALONG WITH
LITTLE CHANGE IN THE VERTICAL PROFILE MEANS AREAS OF LIGHT RAIN
AND FOG WILL PERSIST.

.LONG TERM FORECAST...GFS/ECMWF ARE COMING INTO BETTER AGREEMENT
WITH THE GENERAL PATTERN IN THE DAY 4 THROUGH 7 TIME PERIOD WITH
A BROAD TROUGH PERSISTING OVER MAINLAND ALASKA AND ANOTHER TROUGH
MOVING FROM ASIA INTO THE BERING SEA MID TO LATE NEXT WEEK. THERE
ARE SIGNIFICANT DIFFERENCES IN THE AMPLITUDE OF THE WESTERN TROUGH
SO CONFIDENCE DIMINISHES FURTHER OUT IN TIME. FOR MAINLAND ALASKA
EXPECT A CONTINUED CHANCE OF SHOWERS...PRIMARILY DIURNAL IN
NATURE...ALONG WITH OCCASIONAL BREAKS OF SUN. THE WESTERN TROUGH
WILL TRIGGER FORMATION OF A SURFACE LOW PRESSURE SYSTEM WHICH WILL
BRING RAIN ACROSS THE BERING SEA AND ALEUTIANS WITH THE POSSIBILITY
OF THIS REACHING THE MAINLAND BY LATE NEXT WEEK.

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

SEB AUG 11