Flash Flood, Hawaii
- When
- August 9, 5:05 PM HST to 8:07 PM HST
- Where
- Hawaii County, Naalehu
- Reported by
- EMERGENCY MANAGER
- Coordinates
- 19.067, -155.567
Flash Flood in Hawaii, August 9, 2005
Heavy showers in the Kau District on the Big Island of Hawaii caused county officials to close Highway 11, Hawaii Belt Road, for a couple of hours in the Kawa Flats area. Civil Defense reported 3 to 4 feet of water flowing across the highway.
Where it happened
Every event with a place to put it. Tap one for its entry below.
- Tornadoes
- Tropical storms and surge
- Floods
- Wind
- Hail
- Winter weather
- Heat and drought
- Cold
- Fire, smoke and dust
- Marine and coastal
- Other
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- Crop damage
- None recorded
- Events
- 1
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
What happened
The episode as NWS HFO wrote it up.
Heavy showers in the Kau District on the Big Island of Hawaii caused county officials to close Highway 11, Hawaii Belt Road, for a couple of hours in the Kawa Flats area. Civil Defense reported 3 to 4 feet of water flowing across the highway. There were no reports of serious injuries or property damage, however.
What forecasters said that day
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Honolulu, HI wrote its last area forecast discussion before the first event at Aug 9, 3:38 PM HST, 1 hour 27 minutes earlier.
Area forecast discussion, Aug 9, 3:38 PM HST, 1 hour 27 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 338 PM HST TUE AUG 9 2005 .SYNOPSIS... AN UPPER LEVEL TROUGH TO OUR NORTHWEST WILL CONTINUE TO KEEP THE ATMOSPHERE RATHER UNSTABLE OVER THE BIG ISLAND THROUGH THE NEXT DAY OR SO. AFTERNOON HEATING MAY SPARK SOME LOCALLY HEAVY SHOWERS OVER THE KONA SLOPES. WINDWARD AND MAUKA SECTIONS OF ALL ISLANDS WILL SEE LIGHTER SHOWERS...MOSTLY DURING THE NIGHTS AND EARLY MORNINGS. MODERATE TRADES WILL WEAKEN BY THE END OF THE WORK WEEK. && .DISCUSSION... ONCE AGAIN THIS AFTERNOON WE HAVE SEEN DEEP CONVECTION AND LOCALLY HEAVY SHOWERS BUILD UP OVER THE INTERIOR OF THE BIG ISLAND. THE 00Z HILO SOUNDING DEFINITELY TELLS THE STORY WITH A DEEP MOIST LAYER EXTENDING TO 700 MB...NO CONVECTIVE CAP...WITH A PRECIPITABLE WATER OF 1.77 INCHES AND A CAPE OF 1165 J/KG. THE LOSS OF DAYTIME HEATING WILL LEAD TO A GRADUAL DEMISE OF THE SHOWERS THERE THIS EVENING. VISIBLE SATELLITE IMAGERY SHOWS THAT OTHERWISE...IT IS QUIET UPSTREAM FROM THE ISLANDS AND IT SHOULD BE A RATHER DRY NIGHT FOR MOST AREAS. THE WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL TROUGH ORIENTED WSW TO ENE TO THE NORTH OF THE MAIN HAWAIIAN ISLANDS. THE SUBTROPICAL JET EXTENDS ACROSS THE ISLANDS ON THE SOUTH SIDE OF THE UPPER TROUGH. THESE FEATURES HAVE BEEN HELPING TO MAKE THE ATMOSPHERE MORE UNSTABLE THAN USUAL OVER THE ISLANDS...AND THE DIMINISHING MOISTURE THAT WAS ON THE PERIPHERY OF EX-TD 01C HAS BEEN FUEL FOR THE CONVECTION OVER THE BIG ISLAND. EXPECTING TO SEE A WEAKER CONVECTIVE PATTERN WEDNESDAY AND THURSDAY AFTERNOONS AS THE FEATURES CURRENTLY IN CONTROL OF OUR WEATHER SLOWLY GIVE WAY TO MORE A MORE SETTLED PATTERN. MODELS ARE IN EXCELLENT AGREEMENT...AND THEY SHOW THE UPPER TROUGH NEAR THE ISLANDS WEAKENING AND LIFTING OUT...AND UPPER RIDGING DEVELOPING EAST OF THE ISLANDS BUILDING WESTWARD AND NORTHWARD...GENERALLY TOWARD THE ISLANDS. FORECAST SOUNDINGS SHOW THE TRADE WIND INVERSION REDEVELOPING. THE SUBTROPICAL RIDGE WELL TO THE NORTH GRADUALLY WILL PUSH SOUTH...AND THE LOW LEVELS DRY OUT QUITE A BIT. WE MAY SEE TRADE WIND MOISTURE INCREASE AGAIN EARLY NEXT WEEK. WE HAVE TRENDED THE GRIDS DRIER WITH BELOW CLIMO RAIN CHANCES AND MORE SUNSHINE LATE IN THE WORK WEEK AND INTO THE NEXT WEEKEND. OUR CURRENT MODERATE TRADES WILL LIKELY DROP OFF A BIT TOWARD THE WEEKEND...WITH LIGHT WINDS EXPECTED AT NIGHT. HOPEFULLY THE RECENT RAINS ON THE BIG ISLAND...ALONG WITH WHATEVER FALLS THE NEXT COUPLE DAYS...HAVE BEEN ENOUGH TO ADDRESS WILDFIRE CONCERNS. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && R BALLARD
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Flash Flood in Arizona, August 9, 2005
- Hail in Nebraska, August 9, 2005
- Flash Flooding and Damaging Wind in California, August 9, 2005
- Lightning Strike in Arizona, August 9, 2005
- Hail and Damaging Winds in Minnesota, August 9, 2005
- Damaging Wind in Iowa, August 9, 2005
- Flash Flood and Flood in Maryland, August 9, 2005
- Damaging Wind in Iowa, August 9, 2005
- Damaging Wind in Iowa, August 9, 2005
- Hail and Damaging Winds in Wisconsin, August 9, 2005
- Flash Flood in Arizona, August 9, 2005
- Hail and Damaging Winds in Iowa, August 9, 2005
More
Every storm in Hawaii in 2005Every state in 2005This day in weather historyWarnings in Hawaii, August 2005
Sources
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5469483.