Name: Flash Flood in Hawaii, March 19, 2006
Start: 2006-03-19T09:40
End: 2006-03-19T14:00
Location: Hawaii

Where it happened

Every event with a place to put it. 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 downpours occurred across the island of Oahu on the 19th. Flash flooding closed Waipahu Depot Road in Waipahu for a time as showers and thunderstorms moved through the southeast parts of the isle. No serious property damage or injuries were reported.

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 Mar 19, 4:00 AM HST, 5 hours 40 minutes earlier.

Area forecast discussion, Mar 19, 4:00 AM HST, 5 hours 40 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST SUN MAR 19 2006

.SYNOPSIS...
UNSTABLE SHOWERY WEATHER WILL CONTINUE ACROSS THE MAIN HAWAIIAN
ISLANDS THROUGH THE FORECAST PERIOD...THANKS TO PERSISTENT LOW
PRESSURE TO OUR WEST. WINDS WILL REMAIN RATHER LIGHT...CAUSING
RAINFALL TO INCREASE FROM LATE MORNING THROUGH EVENING EACH DAY THEN
DECREASE AT NIGHT. THUNDERSTORMS AND HEAVY RAINFALL ARE POSSIBLE
THROUGH TODAY.

&&

.DISCUSSION...
MODERATE TO HEAVY SHOWERS PERSIST ACROSS SOUTHEAST PORTIONS OF THE
BIG ISLAND...BUT UNTIL RECENTLY SHOWERS HAVE DIMINISHED ELSEWHERE
ACROSS THE REMAINING ISLANDS OVERNIGHT. WE ARE SEEING A RESURGENCE
IN SHOWER DEVELOPMENT OVER WATER NEAR KAUAI WITHIN THE PAST FEW
HOURS. OVERNIGHT SOUNDINGS SHOWED THE ATMOSPHERE REMAINS WET AND
UNSTABLE WITH K INDICES OF 30 OR GREATER AND PRECIPITABLE WATER
BETWEEN 1.55 AND 1.8 INCHES. THE ATMOSPHERE IS RIPE FOR HEAVY
RAINFALL. ALL THAT IS NEEDED IS A CONVECTIVE TRIGGER LIKE DAYTIME
HEATING OR AN INTERACTION OF OUTFLOW BOUNDARIES.

THE CURRENT UNSTABLE AND WET WEATHER PATTERN WILL CONTINUE THROUGH
THE FORECAST PERIOD. AN UPPER TROUGH 300 TO 500 MILES WEST OF THE
MAIN ISLANDS IS CONSOLIDATING INTO AN UPPER LOW...A FEATURE THAT THE
STORM TRACK WESTERLIES WILL HAVE GREAT DIFFICULTY DIGGING OUT FOR
THE NEXT WEEK. GFS75 SHOWS THIS UPPER LOW WILL OPEN UP INTO A TROUGH
AGAIN LATE FRIDAY...BUT WILL REMAIN ANCHORED WEST OF THE ISLANDS
INTO NEXT WEEKEND. THIS PERSISTENT TROUGHING ALOFT WILL INDUCE A
SURFACE TROUGH WEST OF THE ISLANDS AS WELL THROUGH THE NEXT WEEK...A
FEATURE WHICH WILL KEEP OUR WINDS LIGHT AND THE ISLANDS SUBJECT TO
INCREASED DAYTIME RAINFALL DUE TO HEATING.

LATEST GFS75 BRINGS PULSES OF HEAVY RAINFALL TO THE ISLANDS OVER THE
COMING WEEK. TODAY...WEDNESDAY AND FRIDAY ARE THE DAYS THESE PULSES
ARRIVE...COINCIDING WITH THE FORECAST FORMATION AND PASSAGE OF SHORT
WAVES ALOFT. THE FORECAST CALLS FOR THE POSSIBILITY OF HEAVY
RAINFALL AND THUNDERSTORMS THROUGH TODAY. A FLASH FLOOD WATCH
REMAINS IN EFFECT THROUGH MONDAY EVENING TO ACCOUNT FOR JUST
MODERATE RAINFALL POTENTIALLY TRIGGERING FLOODING ACROSS SOAKED AND
SATURATED GROUND.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...

FLASH FLOOD WATCH...ALL ISLANDS THROUGH MONDAY EVENING.

&&

POWELL

In the hours before

Local storm report, Mar 19, 8:21 AM HST, 1 hour 19 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
821 AM HST SUN MAR 19 2006

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

0650 AM     FLASH FLOOD      NAALEHU                 19.08N 155.57W
03/19/2006                   HAWAII             HI   EMERGENCY MNGR

            BIG ISLAND CIVIL DEFENSE REPORTS THAT HIGHWAY 11 IS
            CLOSED NEAR NAALEHU DUE TO FLOODING ALONG THE HIGHWAY IN
            THE KAU DISTRICT.

0810 AM     HEAVY RAIN       5 ENE HALEIWA           21.61N 158.04W
03/19/2006  U0.00 INCH       HONOLULU           HI   PUBLIC

            HEAVY RAIN CAUSING WATER ON THE KAM HIGHWAY BETWEEN
            SUNSET BEACH AND WAIMEA BAY

0810 AM     LIGHTNING        KAILUA                  21.40N 157.74W
03/19/2006                   HONOLULU           HI   PUBLIC

            LIGHTNING STRUCK AN ELECTRICAL SUBSTATION IN POHAKUPU
            CAUSING POWER OUTAGE

&&

NASH

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: March 19, 9:40 AM HST to 2:00 PM HST
Where: Honolulu County, Countywide
Reported by: EMERGENCY MANAGER
Coordinates: 21.500, -158.000

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 2006 Every state in 2006 This day in weather history Warnings in Hawaii, March 2006

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: 5495602.