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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
330 AM HST TUE JUL 28 2015

.SYNOPSIS...
TRADE WINDS WILL REMAIN LIGHT ENOUGH TO ALLOW AFTERNOON SEA BREEZES 
TO FORM ALONG MOST LEEWARD AREAS TODAY. SHOWERS WILL REMAIN FOCUSED 
ACROSS WINDWARD AREAS...WITH SPOTTY AFTERNOON SHOWERS DEVELOPING 
ACROSS LEEWARD AREAS. LOCALLY FRESH TRADE WINDS AND TYPICAL WINDWARD 
AND MAUKA SHOWERS WILL RETURN ON WEDNESDAY...WITH AN INCREASE IN 
SHOWERS POSSIBLE DURING THE WEEKEND.

&&

.DISCUSSION...
THERE IS LITTLE CHANGE IN FORECAST PHILOSOPHY FROM LAST EVENING. AN 
EAST TO WEST RIDGE ALONG 41N...FAR NORTH OF THE MAIN HAWAIIAN 
ISLANDS...WOULD NORMALLY DRIVE MODERATE TO LOCALLY STRONG TRADE 
WINDS ACROSS LOCAL WATERS. HOWEVER...SURFACE TROUGHING BETWEEN THE 
RIDGE AND THE ISLANDS HAS SLACKENED THE PRESSURE GRADIENT AND KEPT 
TRADE WINDS IN THE LIGHT TO MODERATE RANGE SINCE SUNDAY. A WIND 
DIRECTION JUST SOUTH OF DUE EAST ALSO PROVIDES A BIT OF BLOCKING. 
WEAKER TRADE WINDS USUALLY ALLOW LOCAL LAND AND SEA BREEZES TO FORM 
AND WE DID SEE THIS YESTERDAY...ALONG WITH CONTINUED WARM 
TEMPERATURES. WE EXPECT TRADE WINDS TO STRENGTHEN GRADUALLY THROUGH 
THE WEEK...BUT ANOTHER SEA BREEZE DAY MAY BE IN ORDER FOR LEEWARD 
AREAS TODAY AS WE TRANSITION TO A FULL TRADE WIND PATTERN. 

BY WEDNESDAY...MODELS SHOW THE WEAK SURFACE TROUGHING TO OUR NORTH 
WILL MOVE FAR ENOUGH WEST OF THE MAIN HAWAIIAN ISLANDS TO ALLOW 
STRONGER TRADE WINDS TO BUILD IN FROM THE EAST. WIND DIRECTION WILL 
ALSO BACK A BIT TO EASTERLIES. PREVAILING TRADE FLOW WILL BE STRONG 
ENOUGH TO PREVENT SEA BREEZES FROM FORMING IN THE AFTERNOONS AND 
EVENINGS...CAUSING THE FOCUS FOR CLOUDS AND SHOWERS TO SWITCH BACK 
TO WINDWARD AND MAUKA AREAS. 

FORECAST UNCERTAINTY REMAINS HIGH AS WE HEAD INTO THE WEEKEND. 
MODELS HINT AT INCREASED MOISTURE OVER THE ISLANDS AS THE REMNANTS 
OF TROPICAL DEPRESSION 08E MOVE BY. THE CURRENT OFFICIAL FORECAST 
FROM THE NATIONAL HURRICANE CENTER DISSIPATES THIS SYSTEM A COUPLE 
HUNDRED MILES EAST OF THE BIG ISLAND FRIDAY AFTERNOON...BUT THE 
ASSOCIATED MOISTURE WILL PERSIST AND MOVE WITHIN THE TRADES. IN 
RESPONSE TO THIS...OUR FORECAST CALLS FOR GENERALLY WETTER TRADE 
WEATHER SUNDAY AND MONDAY.
 
&&

.AVIATION... 
SEA BREEZES DURING THE DAY AND LAND BREEZES AT NIGHT CAN BE EXPECTED 
UNTIL THE TRADES STRENGTHEN ENOUGH TO DEFEAT THEM WEDNESDAY. 
INTERIOR AND MOUNTAIN CLOUDINESS DURING THE AFTERNOON WILL RESULT 
FROM DAYTIME HEATING. SOME WINDWARD SECTIONS MAY EXPERIENCE MVFR 
CONDITIONS FROM TIME TO TIME FROM THE CLOUDS BROUGHT IN BY THE 
TRADES. OTHERWISE...VFR CONDITIONS ARE EXPECTED TO PREVAIL OVER MOST 
AREAS.

NO AIRMETS ARE CURRENTLY IN EFFECT.

&&

.MARINE...
LOCAL BUOYS CONTINUE TO SHOW JUST ENOUGH ENERGY ASSOCIATED WITH A 
SOUTH SWELL TO WARRANT CONTINUATION OF THE HIGH SURF ADVISORY FOR 
ALL SOUTH FACING SHORES THROUGH THIS AFTERNOON. HOWEVER...THIS SWELL 
IS ACTUALLY DECLINING AND WILL SLOWLY SUBSIDE OVER THE NEXT SEVERAL 
DAYS. NO OTHER SIGNIFICANT SWELL ARE EXPECTED THIS WEEK.

WITH TRADE WINDS DUE TO BUILD ON WEDNESDAY...A SMALL CRAFT ADVISORY 
FOR THE TYPICALLY WINDY WATERS AROUND THE BIG ISLAND AND MAUI WILL 
LIKELY BE POSTED SOMETIME WEDNESDAY. ONCE UP...THE ADVISORY SHOULD 
REMAIN IN PLACE THROUGH THE WEEKEND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
HIGH SURF ADVISORY UNTIL 6 PM HST TODAY FOR SOUTH FACING SHORES OF 
ALL HAWAIIAN ISLANDS. 

&&

$$

DISCUSSION/MARINE...POWELL
AVIATION...KINEL







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