Name: Flash Flood in Hawaii, August 3, 2004
Start: 2004-08-03T11:27
End: 2004-08-03T15:55
Location: Hawaii

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

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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 rain, showers, and isolated thunderstorms, produced by an upper trough enhancing the remnants of Hurricane Darby, caused flash flooding over southern coastal and lower upslope sections of East Maui. Piilani Highway was closed for a time near Kaupo because of deep ponding over the road surface. There were no reports, however, of serious injuries or property damage.

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 3, 10:00 AM HST, 1 hour 27 minutes earlier.

Area forecast discussion, Aug 3, 10:00 AM HST, 1 hour 27 minutes before

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST TUE AUG 3 2004

.SYNOPSIS...
THE REMNANTS OF DARBY WILL CONTINUE TO AFFECT THE ISLANDS THROUGH
WEDNESDAY AS IT MAKES ITS WESTWARD JOURNEY ACROSS THE ISLANDS.
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS CAN BE EXPECTED. MORE
TYPICAL TRADE WIND WEATHER CAN BE EXPECTED THURSDAY AND FRIDAY AS
SHOWERS BECOME MORE ISOLATED MAINLY OVER WINDWARD AND MAUKA AREAS.

&&

.DISCUSSION...
SHOWERS AND THUNDERSTORMS CONTINUE TO AFFECT THE ISLANDS THIS
MORNING AS THE REMNANT MOISTURE OF DARBY INTERACTS WITH AN UNSTABLE
ATMOSPHERE IN PLACE OVER THE ISLANDS. THE INSTABILITY IS DUE TO AN
UPPER LEVEL TROUGH JUST WEST OF KAUAI. THE THUNDERSTORMS HAVE BEEN
AFFECTING MAINLY THE BIG ISLAND AND ADJACENT WATERS BUT THE REST OF
THE STATE MAY SEE MORE OF THE ACTIVITY LATER TODAY AND TONIGHT.
SHOWERY WEATHER LIKELY LINGER INTO WEDNESDAY ESPECIALLY OVER THE
WESTERN END OF THE MAIN ISLAND CHAIN SINCE THE MOISTURE FIELD IS
ONLY MOVING GRADUALLY WESTWARD. WINDS ARE BASICALLY LIGHT TRADES
ACROSS THE STATE BUT THE REMNANT LOW AND ASSOCIATED THUNDERSTORMS IS
CAUSING SOME VARIABILITY IN WIND DIRECTION AND SPEEDS ESPECIALLY
AROUND MAUI AND THE BIG ISLAND.

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 AREA OF SHOWERY WEATHER THAT MAY
APPROACH THE ISLANDS OVER THE WEEKEND. TROPICAL DEPRESSION SIX-E IS
LOCATED ABOUT 1500 MILES EAST SOUTHEAST OF HONOLULU. THE NATIONAL
HURRICANE CENTER IN MIAMI HAS REDUCED THE CHANCES OF THIS SYSTEM
DEVELOPING BUT THE GFS AND NOGAPS MODELS STILL BRING A LARGE AREA OF
TROPICAL MOISTURE OVER THE STATE LATE FRIDAY INTO SATURDAY BRINGING
THE THREAT OF HEAVY RAINFALL ONCE AGAIN TO THE STATE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WARNING NORTH AND SOUTH KONA ON THE BIG ISLAND.
HIGH SURF ADVISORY EAST SHORES OF KAUAI OAHU MOLOKAI MAUI AND THE
BIG ISLAND.
FLASH FLOOD WATCH ALL ISLANDS.

&&

BURKE

In the hours before

Local storm report, Aug 3, 7:48 AM HST, 3 hours 39 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
748 AM HST TUE AUG 03 2004

..TIME...   ...EVENT...     ...CITY LOCATION...      ...LAT.LON...
..DATE...   ....MAG....     ..COUNTY LOCATION...ST.. ...SOURCE....
            ..REMARKS..

0600 AM     FLASH FLOOD      CAPTAIN COOK            19.50N 155.92W
08/03/2004                   HAWAII             HI   COUNTY OFFICIAL

            SAINT JOHNS ROAD CLOSED DUE TO FLOODING.

0630 AM     FLASH FLOOD      KAILUA-KONA             19.64N 155.99W
08/03/2004                   HAWAII             HI   COUNTY OFFICIAL

            ALL PUBLIC SCHOOLS CLOSED NORTH KONA. EXCESSIVE RUNOFF
            REPORTED.

&&

BURKE

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Maui

When: August 3, 11:27 AM HST to 3:55 PM HST
Where: Maui County, Kipahulu
Reported by: OFFICIAL NWS OBS.
Coordinates: 20.868, -156.617 (the zone’s center; the record gives no point)

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

More

Every storm in Hawaii in 2004 Every state in 2004 This day in weather history Warnings 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: 5431595.