983 FXHW60 PHFO 300658 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 830 PM HST TUE SEP 29 2015 .SYNOPSIS... A HIGH TO THE NORTH WILL MAINTAIN LOCALLY BREEZY TRADE WINDS FOR THE NEXT FEW DAYS. THE TRADE WINDS WILL FOCUS SHOWERS OVER MAINLY WINDWARD AREAS. QUITE A FEW SHOWERS WILL SPREAD LEEWARD TONIGHT AS THE TRADES PUSH A BAND OF SHOWERY LOW CLOUDS OVER THE ISLANDS. THE WEATHER WILL DRY OUT A BIT TOMORROW...BUT WINDWARD AREAS WILL REMAIN RATHER SHOWERY. A DEEP TROUGH ALOFT AND A TROPICAL DISTURBANCE COULD COMBINE TO PRODUCE WET AND WINDY WEATHER STARTING AS EARLY AS SATURDAY. THE UNSETTLED WEATHER COULD CONTINUE FOR SEVERAL DAYS. && .DISCUSSION... SATELLITE LOOPS SHOW AN EAST NORTHEAST TO WEST SOUTHWEST BAND OF SHOWERY LOW CLOUDS MOVING OVER THE ISLANDS IN THE TRADE-WIND FLOW. THIS CLOUD BAND WILL KEEP WINDWARD AREAS QUITE SHOWERY TONIGHT AND LEEWARD AREAS OF THE SMALLER ISLANDS WILL SEE SOME SHOWERS AS WELL. A 1021 MB SURFACE HIGH ABOUT 850 MILES NORTH NORTHEAST OF OAHU WILL MOVE SOUTHEAST AND WEAKEN TO A RIDGE OVER THE NEXT FEW DAYS. HOWEVER LOW PRESSURE SOUTH OF THE ISLANDS WILL KEEP THE PRESSURE GRADIENT TIGHT ENOUGH TO MAINTAIN LOCALLY BREEZY TRAD WINDS THROUGH FRIDAY. SHOWERS CARRIED BY THE TRADE WINDS WILL KEEP WINDWARD AREAS A BIT SHOWERY BUT LEEWARD AREAS WILL BE MOSTLY FAIR FROM WEDNESDAY THROUGH FRIDAY. THE GLOBAL MODELS CONTINUE TO SHOW A TROUGH ALOFT FAR NORTH OF THE AREA DIGGING SOUTH RAPIDLY. A SURFACE LOW WILL CUT OFF TO THE NORTHEAST OF THE ISLANDS BY FRIDAY AFTERNOON. MEANWHILE...ONE OR MORE TROPICAL DISTURBANCES MAY DEVELOP IN AN AREA OF DISTURBED WEATHER ASSOCIATED WITH THE MONSOON TROUGH SOUTHWEST OF THE MAIN HAWAIIAN ISLANDS ALONG 15N. THE MODELS SUGGEST THAT THE WINTRY TROUGH TO THE NORTHEAST MAY PULL MOISTURE UP OVER THE ISLANDS FROM THE DEEP TROPICS. ONE OR MORE TROPICAL CYCLONES COULD EVEN MOVE TOWARD THE ISLANDS FROM THE SOUTHWEST. SO...THE WEATHER OVER THE ISLANDS MAY BECOME VERY UNSETTLED STARTING AS EARLY AS SATURDAY AND CONTINUING INTO AT LEAST THE FIRST HALF OF NEXT WEEK. AT THIS TIME THE DETAILS OF THIS COMPLEX PATTERN ARE STILL UNCLEAR. && .AVIATION... THE LOCALLY STRONG TRADE WINDS WILL CONTINUE TO PRODUCE LOW LEVEL TURB...SO AIRMET TANGO WILL REMAIN IN EFFECT FOR TURB S THRU W OF THE MTN OF ALL THE ISLANDS THROUGH AT LEAST TONIGHT AND PROBABLY LONGER. A BAND OF SHOWERY LOW CLOUDS WILL CONTINUE TO PRODUCE MVFR CEILINGS AND VSBY IN CLD AND SHRA OVER WINDWARD AREAS THROUGH TONIGHT. AIRMET SIERRA WILL REMAIN UP R MTN OBSC OVERNIGHT. COND ARE EXPECTED TO IMPROVE WEDNESDAY AS THE SHOWER BAND CLEARS THE ISLANDS. && .MARINE... A SMALL CRAFT ADVISORY...SCA...REMAINS IN EFFECT FOR ALL WATERS THROUGH TONIGHT FOR STRONG TRADE WINDS AND ROUGH SEAS. WINDS AND SEAS WILL SUBSIDE A BIT OVER THE NEXT COUPLE OF DAYS...BUT THE SCA WILL LIKELY STAY UP FOR THE WINDY ZONES AROUND THE BIG ISLAND AND MAUI...AND MAY NEED TO STAY UP FOR SOME OTHER AREAS AS WELL. THE BREEZY TRADES WILL KEEP SURF ELEVATED ALONG EAST FACING SHORES THROUGH THE WEEK. A NORTH NORTHEAST SWELL EXPECTED TO ARRIVE FRIDAY COULD BRING ADVISORY LEVEL SURF TO NORTH AND EAST FACING SHORES THIS WEEKEND. && .HFO WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY UNTIL 600 AM WEDNESDAY FOR ALL HAWAIIAN WATERS. && $$ DONALDSON