Funnel Cloud in Hawaii, September 11, 2003

HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
10 AM HST THU SEP 11 2003

SUMMARY...A LIGHT WIND PATTERN CONTINUES OVER THE HAWAIIAN ISLANDS.
THE AIR MASS REMAINS MOIST AND UNSTABLE SO LOCALIZED HEAVY
RAINFALLS ARE POSSIBLE. HEAVIEST SHOWERS ARE LIKELY OVER THE WESTERN
END OF THE CHAIN OVER KAUAI AND OAHU. RAINFALL DURING THE NEXT FEW
DAYS WILL BE MOST LIKELY TO OCCUR DURING AFTERNOON AND EARLY EVENING
HOURS OVER INTERIOR SECTIONS OF THE ISLANDS.

DISCUSSION...A MOIST AND UNSTABLE AIR MASS REMAINS OVER THE ISLANDS
PARTICULARLY SO OVER THE WESTERN ISLANDS OF KAUAI AND OAHU.
TROUGHING IN THE UPPER FLOW TO THE NORTHWEST OF THE STATE WITH THE
TROUGH AXIS BETWEEN THE DATELINE AND 160W TOGETHER WITH AN UPPER
LEVELAS WELL AS LOW LEVEL ANTICYCLONE OFF THE U.S. WEST COAST IS
KEEPING THE ISLANDS AREA IN A LIGHT WIND REGIME THAT MAY LAST A
COUPLE OF MORE DAYS. THE RIDGE IN THE SURFACE FLOW TO THE NORTH AND
THE ANTICYCLONE TO THE NORTHEAST ARE ROUNDED WITH THE RIDGE AXIS
NOT WELL DEFINED. THIS MAKES IT EASY FOR SMALL CYCLONIC
PERTURBATIONS TO ROTATE THROUGH THE FLOW COMING IN FROM THE EAST AND
SETTING OFF SHOWERS WITHIN THE MOISTURE LADEN LOW LEVEL FLOW OUT OF
THE SOUTHEAST. KAUAI AND OAHU ARE MORE UNDER THE INFLUENCE OF THE
TROUGH TO THE NORTHWEST WITH ITS UPPER SOUTHWESTERLIES OVERSPREADING
THE STATE SETTING OFF THE SHOWERS. IT IS UNLIKELY THAT THE HEAVY
RAINS ON THE KOOLAUS LAST NIGHT WILL REPEAT THEMSELVES TONIGHT OR IN
THE NEAR FUTURE. THERE IS ONLY A SLIGHT CHANCE THAT THE SOUTHEAST
FLOW WILL CAUSE SHOWERS ALONG THE WINDWARD SLOPES.  WE ARE MORE
LIKELY TO SEE CLEARING OVER LAND DURING THE NIGHTTIME HOURS WITH
SOME CONVECTIVE SHOWERS DEVELOPING ONCE MORE TOMORROW AFTERNOON.
THE TRADES MAY NOT COME BACK FOR SEVERAL MORE DAYS SO THE FORECAST
CALLS FOR LIGHT WINDS THROUGH THE WEEKEND.
ROSENDAL

.HFO...WARNINGS...WATCHES...NONE
.      ADVISORIES...NONE