Flash Flood, Kauai
- When
- August 4, 11:35 AM HST to 1:45 PM HST
- Where
- Kauai County, Countywide
- Reported by
- OFFICIAL NWS OBS.
- Coordinates
- 22.011, -159.705 (the zone’s center; the record gives no point)
Flash Flood in Hawaii, August 4, 2004
Heavy showers and isolated thunderstorms, associated with the remnants of Hurricane Darby, generated flash flooding conditions over most of Kauai. Excessive runoff closed several roads for a time and snarled traffic.
Where it happened
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 and isolated thunderstorms, associated with the remnants of Hurricane Darby, generated flash flooding conditions over most of Kauai. Excessive runoff closed several roads for a time and snarled traffic. The Wailua River exceeded the flash flood threshold during the late morning and into the afternoon hours on the 4th. However, there were no reports of serious property damage or injuries.
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 4, 10:00 AM HST, 1 hour 35 minutes earlier.
Area forecast discussion, Aug 4, 10:00 AM HST, 1 hour 35 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 1000 AM HST WED AUG 4 2004 .SYNOPSIS... TROPICAL MOISTURE FROM THE REMNANTS OF HURRICANE DARBY REMAINS OVER THE WESTERN PORTION OF THE MAIN HAWAIIAN ISLANDS THIS MORNING. HEAVY SHOWERS AND THUNDERSTORMS WILL CONTINUE OVER THE ISLANDS WEST OF MAUI...WITH CONDITIONS CLEARING SLOWLY FROM THE EAST TO WEST. MOLOKAI AND OAHU WILL CLEAR LATER TODAY...THOUGH HEAVY SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER KAUAI BEFORE MIDDAY AND CONTINUE TONIGHT. TRADE WINDS...WITH THEIR MORE NORMAL PATTERN OF WINDWARD AND MAUKA...NIGHT AND MORNING SHOWERS...WILL RETURN ON THURSDAY. && .DISCUSSION... WIDESPREAD RAIN WITH EMBEDDED HEAVY SHOWERS CONTINUES OVER THE ISLAND OF OAHU THIS MORNING...WHILE MOST SHOWER ACTIVITY HAS CLEARED THE BIG ISLAND AND MAUI COUNTY. THE HEAVY RAINFALL WAS DELIVERED BY THE REMNANTS OF FORMER HURRICANE DARBY...NOW A SURFACE TROUGH LOCATED JUST WEST OF OAHU IN THE KAUAI CHANNEL. AMPLE LOW LEVEL MOISTURE FROM THIS SYSTEM IS PASSING UNDER AN UPPER LEVEL TROUGH CENTERED JUST WEST OF THE STATE. THE RESULT IS A VERY FAVORABLE ENVIRONMENT FOR WIDESPREAD RAIN...HEAVY SHOWERS...AND THUNDERSTORMS. AS OF 930 AM HST...OAHU REMAINS UNDER THE HIGHEST CONVERGENCE OF THE LOW LEVEL MOISTURE...WITH THE EASTERN EDGE OF THE CLOUDS AND RAIN OVER WESTERN MOLOKAI. THE SURFACE TROUGH IS MOVING TO THE WEST SLOWLY AND WILL CLEAR OAHU BY LATE THIS AFTERNOON. WITH THE WESTWARD MOVEMENT OF THE SURFACE TROUGH...KAUAI WILL BE THE NEXT ISLAND TO RECEIVE WIDESPREAD RAIN WITH HEAVY SHOWERS. THESE CONDITIONS WILL DEVELOP IN THE NEXT COUPLE OF HOURS. HEAVY SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE ON KAUAI INTO THE NIGHT WITH CLEARING EXPECTED IN THE EARLY MORNING HOURS. BY THURSDAY AND FRIDAY MORE TYPICAL TRADE WIND WEATHER IS EXPECTED THANKS TO HIGH PRESSURE FAR NORTH OF THE STATE. TRADE WINDS WILL BE IN THE 10 TO 20 MPH RANGE WITH SHOWERS MAINLY CONFINED TO WINDWARD AND MAUKA AREAS. && .LONG TERM... WE ARE ALSO WATCHING ANOTHER DECAYING TROPICAL SYSTEM THAT MAY APPROACH THE ISLANDS OVER THE WEEKEND. THE REMNANTS OF TROPICAL DEPRESSION SIX-E ARE LOCATED ABOUT 1150 MILES EAST SOUTHEAST OF HILO. THE GFS MODEL BRINGS A LARGE AREA OF REMNANT TROPICAL MOISTURE OVER THE STATE LATE FRIDAY THROUGH EARLY SUNDAY...PROVIDING A THREAT OF HEAVY RAINFALL ONCE AGAIN TO THE STATE. && .HFO WATCHES/WARNINGS/ADVISORIES... FLASH FLOOD WATCH KAUAI OAHU AND MOLOKAI. && WROE
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
- Damaging Wind and Strong Wind in Ohio, August 4, 2004
- Tornado in Pennsylvania, August 4, 2004
- Flash Flooding in Missouri, August 4, 2004
- Tornado in Pennsylvania, August 4, 2004
- Flash Flood and Damaging Wind in New Mexico, August 4, 2004
- Tornado in Pennsylvania, August 4, 2004
- Flash Flooding and Lightning Strike in Colorado, August 4 to 5, 2004
- Damaging Winds in Maryland, August 4, 2004
- Damaging Winds in Kentucky, August 4, 2004
- Damaging Wind in Kentucky, August 4, 2004
- Damaging Winds in Arkansas, August 4, 2004
- Damaging Wind in Nebraska, August 4, 2004
More
Every storm in Hawaii in 2004Every state in 2004This day in weather historyWarnings in Hawaii, August 2004
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: 5431603.