Name: Flash Flood in Hawaii, May 5 to 6, 2002
Start: 2002-05-05T23:00
End: 2002-05-06T02:00
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.

More than two dozen residents of the Kau District on the Big Island of Hawaii were prevented from making it to their homes because of flooding along the Hawaii Belt Road near Kawa Flats. The road closure lasted for 22 hours, from 11 AM on the 5th through 9 AM on the 6th.

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 5, 8:30 PM HST, 2 hours 30 minutes earlier.

Area forecast discussion, May 5, 8:30 PM HST, 2 hours 30 minutes before

HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST SUN MAY 5 2002

SUMMARY...AN UPPER LEVEL LOW JUST SOUTHWEST OF HAWAII WILL KEEP THE
ISLANDS CLOUDY AND WET THROUGH TUESDAY. WINDS WILL GENERALLY BE FROM
THE EAST. THE WEATHER SHOULD IMPROVE WEDNESDAY...WHEN THE LIFTS OUT
TO THE NORTH.

DISCUSSION...THE UPPER LOW...BEST SEEN ON WATER VAPOR SATELLITE
IMAGERY...WILL LINGER NEARBY FOR ANOTHER COUPLE OF DAYS. IT WILL
THEN MOVE OFF TO THE NORTH TAKING THE UNSTABLE AIRMASS WITH IT.
VISIBLE IMAGERY DURING THE DAY SHOWED SHOWER-BEARING CLOUDS
EXTENDING FAR EAST OF THE ISLANDS. THE TRADES WILL CARRY THESE
CLOUDS INTO THE UNSTABLE ATMOSPHERE OVER THE ISLANDS RESULTING IN
HEAVY SHOWERS.

THE FLOOD WATCH FOR THE BIG ISLAND WILL REMAIN IN EFFECT THROUGH
TONIGHT. ALL THE INGREDIENTS ARE IN PLACE FOR POSSIBLE FLASH
FLOODING...NAMELY ABUNDANT LOW LEVEL MOISTURE AND DIVERGENCE
ALOFT...WITH TERRAIN AND LOW LEVEL CONVERGENCE AS POTENTIAL
TRIGGERS. HEAVY SHOWERS MAY SPREAD WESTWARD ACROSS THE SMALLER
ISLANDS OVERNIGHT.

A SOUTH SWELL WILL ARRIVE WEDNESDAY. SURF WILL INCREASE TO HIGH SURF
ADVISORY LEVEL...POSSIBLY REACHING WARNING LEVEL FOR SOUTH SHORES
THURSDAY THROUGH SATURDAY. CRAIG.

.HFO...WARNINGS...NONE
.      WATCHES...FLOOD BIG ISLAND
.      ADVISORIES...FLOOD SOUTH HAWAII

The radar

The South Shore radar (PHWA), 57 km away, was scanning. The volume nearest the first event began at 09:01 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Hawaii

When: May 5, 11:00 PM HST to May 6, 2:00 AM HST
Where: Hawaii County, 5 mi NNE of Naalehu
Reported by: NEWSPAPER
Coordinates: 19.602, -155.523 (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: 5288910.