833 FXHW60 PHFO 180111 AFDHFO AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 311 PM HST MON JUN 17 2013 .SYNOPSIS... A RIDGE OF HIGH PRESSURE TO THE NORTH WILL KEEP TYPICAL SUMMERTIME TRADE WIND WEATHER OVER THE ISLANDS FOR THE NEXT SEVERAL DAYS. && .DISCUSSION... THE SUBTROPICAL RIDGE IS ABOUT 700 MILES N OF THE ISLANDS... KEEPING MODERATE TRADES BLOWING ACROSS THE CHAIN. AT THE SAME TIME... A TROPICAL UPPER TROPOSPHERIC TROUGH /TUTT/ IS LOCATED JUST W OF THE ISLANDS. THE TUTT APPEARS TO BE ALLOWING A FAIRLY TYPICAL SUMMERTIME DISTRIBUTION OF CLOUDS AND SHOWERS...WITH THE 00Z SOUNDINGS SHOWING A CAPPING INVERSION NEAR 7500 FT. A VERY MINOR SLACKENING OF THE TRADES IS EXPECTED WED-FRI AS GUIDANCE SHOWS THE RIDGE TO THE N TEMPORARILY WEAKENING. THIS SHOULD ALLOW US TO DROP THE SMALL CRAFT ADVISORY ON WED...BUT SHOULD NOT SEE MUCH CHANGE IN THE SHORT PERIOD EAST SHORE WIND SWELL. THE RIDGE WILL LIKELY REESTABLISH ITSELF THIS WEEKEND. THE TUTT WILL WEAKEN A BIT OVER THE NEXT FEW DAYS...AND VERY WARM MID-LEVEL TEMPERATURES TO THE E OF THE ISLANDS SHOULD MOVE IN AND FURTHER STABILIZE THE AIRMASS. PRECIPITABLE WATER VALUES ARE FORECAST TO DROP BELOW NORMAL WED NIGHT AND REMAIN THERE THROUGH THE REST OF THE FORECAST PERIOD. THE DRIER AND MORE STABLE AIR SHOULD RESULT IN EVEN FEWER WINDWARD AND MAUKA SHOWERS. && .HFO WATCHES/WARNINGS/ADVISORIES... SMALL CRAFT ADVISORY UNTIL 6 AM HST WEDNESDAY FOR MAALAEA BAY- PAILOLO CHANNEL-ALENUIHAHA CHANNEL-BIG ISLAND LEEWARD WATERS-BIG ISLAND SOUTHEAST WATERS. && $$ R BALLARD |