AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1145 PM HST THU JUL 7 2011 .SYNOPSIS... FRESH TO LOCALLY STRONG TRADE WINDS WILL CONTINUE THROUGH FRIDAY WITH A GRADUAL DECREASE EXPECTED THIS WEEKEND AND MONDAY. TRADE WINDS WILL REMAIN MODERATE THROUGH NEXT WEEK. CLOUDS AND SHOWERS WILL REMAIN FOCUSED ON WINDWARD AND MAUKA AREAS THROUGH THE PERIOD...WITH MOST OF THE RAIN FALLING DURING THE NIGHT AND EARLY MORNINGS. AN UPPER LOW WILL APPROACH FROM THE EAST SUNDAY AND SKIRT NEAR THE ISLAND CHAIN WHICH MAY ENHANCE THE SHOWERS A BIT SUNDAY NIGHT THROUGH TUESDAY. && .UPDATE... UPDATED MARINE AND WWA BLOCK FOR SCA EXPANSION. && .DISCUSSION... A SURFACE HIGH FAR NORTH OF THE ISLANDS IS CONTINUING TO BRING MODERATE TO LOCALLY STRONG TRADE WINDS TO THE REGION. THIS HIGH WILL REMAIN THE DOMINATE FEATURE THROUGH THE FORECAST PERIOD. AS A RESULT...WE EXPECT TRADE WINDS TO CONTINUE THROUGHOUT. ELEVATED WINDS ARE EXPECTED THROUGH SATURDAY...WITH A DECREASE HEADING INTO SUNDAY AS THE HIGH LIFTS TO THE NORTH AND AN UPPER LEVEL DISTURBANCE MOVES TOWARDS THE ISLANDS FROM THE EAST. THE UPPER LEVEL DISTURBANCE WILL USHER IN ADDITIONAL MOISTURE ON THE TRADES...RESULTING IN ENHANCED TRADE WIND SHOWERS OVER WINDWARD AND MAUKA AREAS AS WE HEAD INTO THE NEW WORK WEEK. THERE REMAINS GOOD MODEL AGREEMENT WITH THE PATTERN THROUGH SATURDAY. SUNDAY ONWARDS...THERE IS GOOD AGREEMENT WITH THE SURFACE HIGH SLOWLY LIFTING NORTH...WITH DIFFERENCES WITH REGARDS TO THE PLACEMENT OF THE UPPER LEVEL LOW. THE ECMWF BRINGS THE UPPER LOW CLOSER TO THE ISLANDS...WHILE THE GFS KEEPS IT TO THE EAST. BOTH MODELS SHOW THE LOW LIFTING TO THE NORTH BY TUESDAY. THE PLACEMENT OF THE LOW WILL IMPACT NOT ONLY THE AMOUNT OF MOISTURE THAT COMES INTO THE ISLANDS...BUT ALSO HOW THE TRADE WINDS WILL WEAKEN. WINDS AT THE TOP OF MAUNA KEA HAVE REMAINED JUST ABOVE ADVISORY LEVELS FOR THE LAST SEVERAL HOURS. WINDS HAVE REMAINED JUST BELOW ADVISORY LEVELS AT HALEAKALA AND MAUNA LOA. ALL OF THESE LOCATIONS REMAIN UNDER A WIND ADVISORY THROUGH TONIGHT...AND WILL BE MONITORING THE WINDS THERE CLOSELY OVERNIGHT. && .MARINE... THE FRESH TRADE WIND FLOW AND ELEVATED SEA ARE BRINGING SMALL CRAFT ADVISORY /SCA/ CONDITIONS TO WATERS NEAR HAWAII. AS A RESULT...THE SCA HAS BEEN EXPANDED TO INCLUDE ALL COASTAL WATERS AND CHANNELS. SCA CONDITIONS ARE EXPECTED TO TO CONTINUE INTO THROUGH SATURDAY...BUT A FEW OF THE WINDER ZONES COULD BE EXTENDED INTO SATURDAY NIGHT. THE EXPECTED DECREASE IN TRADE WINDS SUNDAY AND MONDAY WILL LIKELY LEAD TO DROPPING THE SCA AT THAT TIME. A SOLID S-SSW SWELL IS CURRENTLY IMPACTING SOUTH FACING SHORES OF ALL ISLANDS AND A HIGH SURF ADVISORY IS IN EFFECT. ANOTHER SWELL IS EXPECTED TO ARRIVE FRIDAY AND SATURDAY WHICH WILL KEEP ADVISORY LEVEL SURF ALONG SOUTH FACING SHORES THROUGH SATURDAY. THE ELEVATED TRADE WINDS WILL ALSO PRODUCE SHORT PERIOD SURF THAT WILL CREATE ROUGH CONDITIONS ALONG EAST FACING SHORES OF KAUAI...OAHU... MOLOKAI...MAUI AND THE BIG ISLAND. A HIGH SURF ADVISORY IS IN EFFECT FOR EAST FACING SHORES OF THESE ISLANDS AS A RESULT. && .AVIATION... DUE TO STRONG TRADES...AIRMET TANGO WILL CONTINUE FOR LOW LEVEL TURBULENCE FOR AREAS BELOW 080 S THRU W OF MOUNTAINS FOR THE MAIN HAWAIIAN ISLANDS. ASSOCIATED TRADE SHOWERS WILL BRIEFLY LOWER CEILINGS AND VISIBILITY TO MVFR CONDITIONS OVERNIGHT ON WINDWARD TAF SITES. HOWEVER...VFR CONDITIONS WILL PREVAIL THROUGHOUT THE FORECAST PERIOD. && .HFO WATCHES/WARNINGS/ADVISORIES... HIGH SURF ADVISORY UNTIL 6 PM SATURDAY FOR SOUTH FACING SHORES OF ALL ISLANDS. HIGH SURF ADVISORY FOR UNTIL 6 PM SATURDAY EAST FACING SHORES OF KAUAI-OAHU-MOLOKAI-MAUI-THE BIG ISLAND. WIND ADVISORY UNTIL 6 AM HST FRIDAY FOR HALEAKALA SUMMIT-BIG ISLAND SUMMITS. SMALL CRAFT ADVISORY UNTIL 6 PM HST SATURDAY FOR ALL WATERS. && $$