Heavy Rain in Hawaii, June 5, 2003

HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
10 AM HST THU JUN 5 2003

SUMMARY...AN UPPER LEVEL TROUGH WILL REMAIN OVER THE ALOHA STATE
FOR THE NEXT FEW DAYS...KEEPING THE CHANCE OF LOCALLY HEAVY SHOWERS
OVER THE ISLANDS EACH AFTERNOON. THE TROUGH WILL WEAKEN AND MOVE
EAST OF US THIS WEEKEND. LIGHT WINDS ARE EXPECTED TO PERSIST INTO
THE WEEKEND...KEEPING IT RATHER MUGGY. IT LOOKS LIKE MODERATE TRADE
WINDS WILL MAKE A COMEBACK EARLY NEXT WEEK AS HIGH PRESSURE BUILDS
NORTH OF THE STATE.

DISCUSSION...A TROPICAL UPPER TROPOSPHERIC TROUGH OR TUTT IS
LOCATED JUST WEST OF HAWAII...EXTENDING THROUGH 25N 158W...18N 170W.
THE WATER VAPOR IMAGERY SHOWS A COUPLE SHORTWAVES EMBEDDED WITHIN
THE TROUGH AXIS. ONE SHORTWAVE WHICH MAY HAVE HELPED TO ENHANCE
CONVECTION A BIT YESTERDAY AFTERNOON IS NOW LOCATED FAR TO OUR
NORTHEAST. ANOTHER WEAK SHORTWAVE IS LOCATED NEAR 21N 163.5W AND
MOVING TOWARD THE EAST AROUND 7 KT. THE 12Z SOUNDINGS ARE ACTUALLY A
LITTLE MORE MOIST AND UNSTABLE THAN 24 HOURS AGO. THE PROXIMITY OF
THE TROUGH AND THE WEAK PRESSURE GRADIENT LEADING TO LAND AND SEA
BREEZES WILL MEAN A CONTINUATION OF AFTERNOON SHOWER CHANCES MUCH
LIKE WHAT WE SAW ON WEDNESDAY. THOUGH THE MID LEVELS ARE NOT
ESPECIALLY COLD...THE LOWER LEVELS ARE MOISTURE-RICH AND THUS SOME
OF THE SHOWERS MAY BE LOCALLY HEAVY.

THE SUBTROPICAL JET CONTINUES TO CARRY A PLUME OF HIGH CLOUDINESS
ACROSS A MUCH OF THE STATE. SOUTHWEST WINDS ALOFT WILL CONTINUE
TO BRING OCCASIONAL HIGH CLOUDS OVER US THROUGH THE NEXT COUPLE
DAYS...MOST LIKELY UNTIL THE TUTT AXIS GETS EAST OF US.

GLOBAL MODELS CONTINUE TO SHOW THE SUBTROPICAL RIDGE TAKING UP
RESIDENCE NORTH OF THE STATE THIS WEEKEND WITH SURFACE PRESSURES
SLOWLY RISING NORTH OF THE STATE. THE RIDGE WILL CONTINUE TO
STRENGTHEN EARLY NEXT WEEK...THUS THE LONG AWAITED RETURN OF
MODERATE TRADES IS STILL ON TARGET FOR MONDAY.

CURRENT PACKAGE LOOKS GOOD AND WILL MAKE ONLY MINOR COSMETIC
CHANGES. UPDATED ZFP SHOULD BE OUT BY 10 AM.

R BALLARD

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