Name: Flash Flood in Hawaii, May 6, 2002
Start: 2002-05-06T06:30
End: 2002-05-06T13:30
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: $60,000
Crop damage: $230,000
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.

An upper trough ignited heavy showers and thunderstorms over northwest and central parts of Oahu. Police closed Kamehameha Highway between Kamananui Road in Wahiawa to Weed Junction in Waialua from 630 AM until noon because of flooding. Nineteen residents of Otake Camp in Waialua were evacuated before noon after Kaukonahua Stream flooded some of their homes. Water levels rose up to 8 feet in some low-lying areas.Much of the flooding in and near Waialua was linked to overnight rainfall in Central Oahu and the North Shore that caused Lake Wilson, or the Wahiawa Reservoir, to overflow and spill into Kaukonahua Stream and other waterways that flow through the community. A civil defense official said that the level of Lake Wilson rose six feet above the 80-foot spillway after much of the torrential rain had ended, leading to much of the Waialua flooding. A resident from Otake Camp, after being evacuated from his home, said that stream waters began to rise about one foot every 20 to 30 minutes beginning at 10 AM.Oahu farmers suffered around $230 thousand in crop damage, and $60 thousand in lost equipment and supplies, according to state agriculture officials. The rainfall affected mostly small farmers in Waialua, Haleiwa, and Waiahole. Nearly 80 acres suffered crop damage and major losses of topsoil after the heavy deluge.

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 May 6, 4:17 AM HST, 2 hours 13 minutes earlier.

Area forecast discussion, May 6, 4:17 AM HST, 2 hours 13 minutes before

NARRATIVE SYNOPTIC DISCUSSION FOR AMERICAN SAMOA AND THE INDEPENDENT
STATE OF SAMOA

TODAY THROUGH TUESDAY...

SATELLITE LOOPS SHOW A TRIANGULAR AREA OF BROKEN LAYERED CLOUDS AND
ISOLATED CUMULONIMBUS BOUNDED BY A LINE FROM 10S173W TO TUTUILA TO
15S176W BACK TO 10S173W. THESE CLOUDS ARE ASSOCIATED WITH WEAK
CONVERGENCE IN THE LOW LEVEL EASTERLY FLOW AND TROUGHING ALOFT. A
CLOUD BAND ASSOCIATED WITH THE TRAILING END OF A FRONTAL BAND
REMAINS NEAR NIUE. THE AVN MODEL SHOWS LITTLE CHANGE THROUGH
TUESDAY. YOUR SKIES WILL BE PARTLY TO MOSTLY CLOUDY WITH SCATTERED
SHOWERS AND A CHANCE OF HEAVY SHOWERS OR THUNDERSTORMS. WINDS WILL
BE EAST SOUTHEAST AT 10 TO 15 KNOTS TODAY DECREASING TO 5 TO 10
KNOTS TUESDAY.

A SOUTH SWELL WILL RISE QUICKLY TO NEAR 8 FEET THIS MORNING. THIS
MAY PRODUCE SURF NEAR 15 FEET ALONG THE SOUTH COASTS. THE BIG SWELL
WILL CONTINUE THROUGH THURSDAY.

OUTLOOK FOR WEDNESDAY THROUGH FRIDAY...

THE TRAILING END OF A FRONTAL BAND WILL SHIFT NORTH OVER THE ISLANDS
WEDNESDAY BRINGING MOSTLY CLOUDY SKIES AND CONTINUED SHOWERY
CONDITIONS. THE CLOUD BAND WILL REMAIN OVER THE ISLANDS THROUGH
FRIDAY MORNING BEFORE SHIFTING BACK TO THE SOUTHEAST.

NARRATIVE DISCUSSION FOR TUVALU...

TODAY THROUGH WEDNESDAY...TUVALU TIME...

OUR SATELLITE PICTURES SHOW A 200 NAUTICAL MILE WIDE BAND OF BROKEN
CLOUDS WITH ISOLATED HEAVY SHOWERS NORTH OF A LINE FROM 06S172E TO
60 NAUTICAL MILES NORTH OF FUNAFUTI TO 500 NAUTICAL MILES EAST OF
FUNAFUTI. THESE CLOUDS ARE ASSOCIATED WITH WEAK CONVERGENCE IN THE
LOW LEVEL EASTERLY FLOW AND TROUGHING ALOFT. THE SHOWERS WILL
CONTINUE TO MOVE OVER THE NORTHERN ISLANDS AND WILL GRADUALLY SPREAD
OVER THE SOUTHERN ISLANDS AS WELL. WINDS WILL REMAIN FROM THE EAST
AT 10 KNOTS OR LESS.

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, Honolulu

When: May 6, 6:30 AM HST to 1:30 PM HST
Where: Honolulu County, Waialua
Property damage: $60,000
Crop damage: $230,000
Reported by: NEWSPAPER
Coordinates: 21.455, -157.961 (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 2002 Every state in 2002 This day in weather history Warnings in Hawaii, May 2002

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: 5287963.