Flash Flood in Hawaii, September 15, 2005

HAWAIIAN ISLANDS FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE HONOLULU HI
545 AM HST THU SEP 15 2005

.SYNOPSIS...THE COMBINATION OF TROUGHING ALOFT AND ABUNDANT MOISTURE
NEAR THE SURFACE WILL KEEP HAWAII WEATHER WET THROUGH TODAY. DRIER
AND MORE STABLE WEATHER WILL ARRIVE BY THE WEEKEND. SURF ALONG
SOUTHERN SHORES WILL REMAIN ELEVATED THROUGH FRIDAY.

&&

.DISCUSSION...LITTLE HAS CHANGED FROM SEVEN HOURS AGO. A NORTHWARD
BULGE IN THE INTERTROPICAL CONVERGENCE ZONE HAS INTRODUCED ABUNDANT
LOW LEVEL MOISTURE ACROSS THE MAIN HAWAIIAN ISLANDS. AN UPPER TROUGH
JUST WEST OF THE MAIN ISLANDS IS PROVIDING ENOUGH INSTABILITY FOR
THE ATMOSPHERE TO TAP INTO THAT MOISTURE AND PRODUCE WIDESPREAD
SHOWERS...SOME HEAVY...AND ISOLATED THUNDERSTORMS. THE RAINFALL
FOCUS FROM 6 PM HST WEDNESDAY TO ABOUT MIDNIGHT WAS KAUAI AND
OAHU...WITH THE KUHIO HIGHWAY STILL CLOSED ACROSS THE HANALEI RIVER
ON KAUAI DUE TO FLOODING. THE FOCUS OF RAINFALL SHIFTED EAST TO MAUI
AFTER MIDNIGHT...WHERE SEVERAL RIVERS REACHED OR EXCEEDED FLOOD
STAGE. RADAR SHOWS A WIDE SWATH OF NORTHERN HALEAKALA SLOPES
RECEIVING 4 TO 6 INCHES OF RAIN OVER THE PAST THREE HOURS.

THE 06Z GFS75 SHOWS THE UPPER TROUGH WILL REMAIN NEAR THE ISLANDS
THROUGH LATE TODAY...ENHANCING SHOWERS OVER MAINLY WINDWARD AND
MAUKA AREAS. LEEWARD SLOPES OF THE BIG ISLAND MAY SEE SOME
ENHANCEMENT AS WELL IN THE AFTERNOON AND EVENING. HOWEVER...EVEN
AFTER LIFTING NORTHWARD FRIDAY...MODELS SHOW THE TROUGH CUTS OFF
INTO AN UPPER LOW WHICH NEVER REALLY STRAYS MORE THAN 600 MILES
AWAY. THIS IS APPARENTLY FAR ENOUGH AWAY FOR GFS TO SHOW SIGNIFICANT
DRYING FOR THE ISLANDS FRIDAY AND THEREAFTER. AS THE UPPER TROUGH
LIFTS NORTHWARD...WEAK RIDGING WILL BUILD OVER THE STATE FROM THE
EAST. THIS WILL BRING A SLIGHT INCREASE IN STABILITY AND REDUCE THE
THREAT OF HEAVY SHOWERS FOR THE REMAINDER OF THE FORECAST PERIOD.
MORE IMPORTANTLY...THE REFORMATION OF THE INTERTROPICAL CONVERGENCE
ZONE 500 TO 600 MILES SOUTH OF THE BULGE NEAR THE ISLANDS WILL PUT A
CORK IN THE FLOW OF DEEP TROPICAL MOISTURE NORTHWARD...GIVING
WHATEVER UPPER TROUGH OR LOW WHICH IS AROUND FAR LESS FUEL FOR
HEAVY SHOWER AND THUNDERSTORM DEVELOPMENT. MODERATE TO LOCALLY FRESH
TRADE WINDS WILL PERSIST THROUGH THE WEEKEND AS HIGH PRESSURE
PERSISTS NORTH OF THE STATE. TRADES MAY DECREASE SLIGHTLY EARLY NEXT
WEEK AS THE HIGH MOVES OFF TO THE NORTHEAST.

TROPICAL STORM JOVA IS LOCATED ABOUT 1670 MILES EAST SOUTHEAST OF
HILO. THE OFFICIAL FORECAST...ISSUED BY THE NATIONAL HURRICANE
CENTER IN MIAMI...HAS JOVA STRENGTHENING INTO A MINIMAL HURRICANE
FRIDAY EVENING AS IT REACHES 13.6N 137.7W...ABOUT 1080 MILES EAST
SOUTHEAST OF HILO. JOVA IS THEN FORECAST TO WEAKEN BACK TO TROPICAL
STORM STRENGTH SATURDAY AFTERNOON WHILE STILL FAR SOUTHEAST OF THE
MAIN HAWAIIAN ISLANDS. GIVEN THE UNCERTAINTY INVOLVED IN TRACK
FORECASTING AT DAY FIVE...WE WILL HOLD OFF MAKING ANY CHANGES IN THE
LOCAL FORECAST AT THIS TIME AND WILL MAINTAIN A TRADE WIND FORECAST.
JOVA WILL BE CLOSELY MONITORED AS IT APPROACHES THE REGION. THE
CENTRAL PACIFIC HURRICANE CENTER WILL ASSUME FORECAST RESPONSIBILITY
FOR JOVA WHEN IT CROSSES 140W ON SATURDAY.

&&

.MARINE...SURF ALONG SOUTH FACING SHORES WILL REMAIN ELEVATED AT THE
15 FOOT WARNING LEVEL INTO THIS AFTERNOON. SURF IS EXPECTED TO
SUBSIDE BELOW WARNING LEVEL BY TONIGHT...YET REMAIN ABOVE THE
ADVISORY LEVEL OF 8 FEET INTO EARLY SATURDAY.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
SMALL CRAFT ADVISORY...ALL HAWAIIAN WATERS
HIGH SURF WARNING...SOUTH FACING SHORES
FLOOD WATCH...KAUAI OAHU MOLOKAI MAUI AND BIG ISLAND

&&

POWELL