Heavy Rain, Honolulu
- When
- August 3, 9:20 PM HST to August 4, 3:45 AM HST
- Where
- Honolulu County, Countywide
- Reported by
- OFFICIAL NWS OBS.
- Coordinates
- 21.455, -157.961 (the zone’s center; the record gives no point)
Heavy Rain in Hawaii, August 3 to 4, 2004
Heavy showers and isolated thunderstorms, associated with remnants of Hurricane Darby being enhanced by an upper trough, produced small stream and drainage ditch flooding, and ponding of roadways across the isle of Oahu. There were no reports of serious property damage or injuries.
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 remnants of Hurricane Darby being enhanced by an upper trough, produced small stream and drainage ditch flooding, and ponding of roadways across the isle of Oahu. 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 3, 8:30 PM HST, 50 minutes earlier.
Area forecast discussion, Aug 3, 8:30 PM HST, 50 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 830 PM HST TUE AUG 3 2004 .SYNOPSIS... THE REMNANT TROPICAL MOISTURE FROM TROPICAL STORM DARBY WILL CONTINUE TO BRING SHOWERS...SOME HEAVY...TO THE ISLANDS TONIGHT AND INTO WEDNESDAY. TRADE WINDS...WITH THEIR MORE NORMAL PATTERN OF WINDWARD AND MAUKA...NIGHT AND MORNING SHOWERS...WILL RETURN ON THURSDAY. && .DISCUSSION... HEAVY SHOWERS WHICH HAVE BEEN AFFECTING MOSTLY THE BIG ISLAND AND MAUI LAST NIGHT AND TODAY...ARE MOVING WEST. A SURFACE TROUGH...THE REMNANT OF EX-TROPICAL STORM DARBY...IS NOW ORIENTED SOUTHWEST THROUGH NORTHEAST AND LIES THROUGH THE KAIWI CHANNEL BETWEEN OAHU AND MOLOKAI. A PLUME OF MOIST TROPICAL AIR IS BEING PULLED NORTHWARD ALONG THE EAST SIDE OF THIS TROUGH...WITH DRIER NORTH TO NORTHEASTERLY FLOW ALONG THE WEST SIDE OF THE TROUGH. SHOWERS...SOME BRIEFLY HEAVY...MARK THE TROUGH AND EXTEND EAST TO BEYOND THE BIG ISLAND. THE TROUGH AND SHOWERS ARE MOVING WESTWARD AT ABOUT 10 MPH AND WILL AFFECT ALL ISLANDS THROUGH THE NIGHT TONIGHT AND INTO WEDNESDAY. IT APPEARS MOISTURE MOVING UP FROM THE SOUTH WILL CONVERGE WITH MOISTURE MOVING WESTWARD NORTH OF THE ISLANDS RIGHT OVER OAHU LATER TONIGHT. 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 ISSUED ITS LAST ADVISORY ON THIS SYSTEM BUT THE GFS AND NOGAPS MODELS STILL BRING A LARGE AREA OF REMNANT 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 WATCH ALL ISLANDS. HIGH SURF ADVISORY EAST SHORES OF KAUAI OAHU MOLOKAI MAUI AND THE BIG ISLAND. && FARRELL
In the hours before
Local storm report, Aug 3, 8:08 PM HST, 1 hour 12 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
808 PM HST TUE AUG 03 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0435 AM FLASH FLOOD KAILUA-KONA 19.64N 155.99W
08/03/2004 HAWAII HI EMERGENCY MNGR
EXCESSIVE RUNOFF REPORTED IN DOWNTOWN STREETS OF TOWN.
&&
FARRELLThe radar
The national radar mosaic for the moment the first event began.
Event by event
1 heavy rain. Local standard time, as filed.
What these are
- Heavy Rain
- Rainfall totals unusual for the place and season that did not produce a flood.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Tornadoes and Flash Flooding in Iowa, August 3 to 4, 2004
- Flash Flooding and Hail in Wisconsin, August 3, 2004
- Hurricane and Flash Flooding in North Carolina, August 3, 2004
- Damaging Wind in Minnesota, August 3, 2004
- Damaging Wind in South Dakota, August 3, 2004
- Damaging Wind in Minnesota, August 3, 2004
- Damaging Wind in Minnesota, August 3, 2004
- Damaging Winds and Lightning Strike in Iowa, August 3, 2004
- Damaging Wind in South Dakota, August 3, 2004
- Hail and Damaging Winds in Iowa, August 3, 2004
- Lightning Strike in Maine, August 3, 2004
- Damaging Wind in New York, August 3, 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: 5431598.