Hawaii, 2006

Flash Flood in Hawaii, April 2, 2006

April 2, 2006 · NWS HFO · 1 event in 1 county or zone

1 flash flood, as filed by the National Weather Service.

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 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 Apr 2, 10:00 AM HST, 5 hours 37 minutes earlier.

Area forecast discussion, Apr 2, 10:00 AM HST, 5 hours 37 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
1000 AM HST SUN APR 2 2006

.SYNOPSIS...
THE UPPER LOW NEAR KAUAI WILL BE WEAKENING TODAY WHILE IT WORKS ITS
WAY DOWN THE MAIN HAWAIIAN ISLANDS. THE TRADE WINDS ARE STILL SLATED
TO RETURN TONIGHT. HOWEVER IT COULD BE WET TRADES THIS WEEK AS A
FRESH TROUGH ALOFT SETTLES OVER THE ISLANDS.
&&

.DISCUSSION...
A THUNDERSTORM HAS DEVELOPED AND MOVED ONSHORE NEAR KANEOHE THIS
MORNING...AND TOWERING CUMULUS ARE NOTED ON THE WINDWARD SIDE OF
OAHU...AND OVER CENTRAL KAUAI. HAVE MODIFIED SEVERAL GRIDS THIS
MORNING...AND WILL LIKELY CONTINUE TO TWEAK THE GRIDS THROUGHOUT THE
DAY. GAGES AND RADAR INDICATE RAINFALL RATES IN EXCESS OF 2 INCHES
PER HOUR WITH THIS STORM...PROMPTING THE ISSUANCE OF AN URBAN AND
SMALL STREAM FLOOD ADVISORY FOR THE WINDWARD SIDE OF OAHU.
ANTICIPATE SIMILAR EVENTS TODAY FOR OAHU...KAUAI AND NIIHAU...THUS
THE FLASH FLOOD WATCH CONTINUES FOR THESE ISLANDS.

EARLIER THIS MORNING...THE KAUAI RADAR WAS PICKING UP FALSE RETURNS
ON NORTHERN OAHU. A NEW CLUTTER SUPPRESSION WAS ADDED TO THE KAUAI
RADAR JUST BEFORE 8 AM THIS MORNING TO CORRECT THIS ISSUE.

MAIN CHANGES THIS MORNING ARE TO THE WINDS THROUGHOUT THE FORECAST
PERIOD. EXPECT THE EAST WINDS TODAY TO STRENGTHEN THROUGHOUT THE
WEEK...BRINGING MORE TYPICAL TRADE WIND WEATHER TO THE STATE. SOME
SHORT TERM MODIFICATIONS HAVE BEEN MADE TO THE POP/SKY/WX GRIDS.
TEMPERATURES AND RELATED FIELDS HAVE ALSO BEEN MODIFIED TO BRING
THEM MORE INLINE WITH THE CURRENT FORECAST PHILOSOPHY OF A RETURN TO
THE TRADE WIND WEATHER PATTERN THIS WEEK.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH KAUAI NIIHAU OAHU THROUGH 8 PM TONIGHT.

&&

M BALLARD

In the hours before

Local storm report, Apr 2, 1:39 PM HST, 1 hour 58 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE HONOLULU HI
139 PM HST SUN APR 02 2006

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

0115 PM     LIGHTNING        HAUULA                  21.59N 157.92W
04/02/2006                   HONOLULU           HI   EMERGENCY MNGR

            LIGHTNING HIT 2 POLES ON KAWAIPUNA STREET. ELECTRICITY IS
            OUT IN HAUULA AND THERE ARE LINES ON THE ROADWAY.

&&

HFO

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
April 2, 3:37 PM HST to 8:37 PM HST
Where
Honolulu County, Kahuku
Reported by
EMERGENCY MANAGER
Coordinates
21.683, -157.950

Heavy showers and isolated thunderstorms impacted a broad section of windward Oahu, producing small landslides and deep ponding on several roadways. The precipitation caused the Waikane Stream to overflow onto a stretch of Kamehameha Highway near the town of Waikane. This closed the roadway in that area for a time. Also, civil defense officials evacuated 12 families below the Kailua Reservoir as a precaution, fearing a breach in the dam. However, there were no serious injuries or property damage.

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 2006Every state in 2006This day in weather historyWarnings in Hawaii, April 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: 5496452.