Hawaii, 2003

Heavy Rain in Hawaii, April 6, 2003

April 6, 2003 · NWS HFO · 1 event in 1 county or zone

Heavy showers and thunderstorms brought small stream and drainage ditch flooding, and ponding of roadways to windward and central areas of Oahu. However, no serious injuries or property damage were reported.

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.

Heavy showers and thunderstorms brought small stream and drainage ditch flooding, and ponding of roadways to windward and central areas of Oahu. However, no serious injuries or property damage 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 Apr 6, 10:00 AM HST, 3 hours 55 minutes earlier.

Area forecast discussion, Apr 6, 10:00 AM HST, 3 hours 55 minutes before
HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
10 AM HST SUN APR 6 2003

REWORDED SUMMARY ONLY

SUMMARY...A BAND OF HEAVY SHOWERS AND THUNDERSTORMS JUST NORTHWEST
OF KAUAI WILL BE PUSHED EASTWARD BY AN UPPER LOW TODAY. THESE STORMS
APPEAR READY TO BRING HEAVY RAINFALL TO KAUAI AND OAHU. THE LOW IS
FORECAST TO WEAKEN WITH TIME HOWEVER...SO ITS EFFECTS MAY NOT REACH
THE OTHER ISLANDS. LIGHT TRADES ARE EXPECTED TO BEGIN RETURNING
LATE MONDAY...WITH INCREASING STRENGTH ON TUESDAY.

DISCUSSION...THE KONA LOW THAT HAS BEEN FLIRTING WITH THE ISLANDS
FOR OVER A WEEK IS NOW SOME 270 MILES WNW OF LIHUE...MOVING ESE AT
ABOUT 20 MPH. A CONVERGENT CONVECTIVE BAND IS WRAPPED AROUND THIS
UPPER LEVEL LOW...FROM NORTH OF THE CENTER TO SOUTHEAST OF THE
CENTER...AND NOW LIES SOME 60 MILES WNW OF LIHUE...MOVING VERY
SLOWLY EASTWARD. THIS PUTS THE GREATES CHANCE FOR HEAVY SHOWERS AND
THUNDERSTORMS ON KAUAI FOR TODAY. IN THE PAST COUPLE OF HOURS...
SHOWERS HAVE BEGUN POPPING UP TO THE SOUTH OF BOTH KAUAI AND
OAHU...OUT AHEAD OF THE MAIN SHOWER BAND. SOME OF THESE SHOWERS ARE
ACTUALLY QUITE HEAVY...AND THEY APPEAR TO BE FORMING INTO LINES.
THUS FLOOD WATCH HAS BEEN ISSUED FOR BOTH KAUAI AND OAHU FOR TODAY
AS A PRECAUTIONARY MEASURE. WITH THE EASTWARD MOVEMENT OF THE UPPER
LEVEL SYSTEM...THE THREAT WOULD NORMALLY BE EXPECTED TO TRANSLATE
EASTWARD TONIGHT INTO MONDAY...BUT THE AVIATION FORECAST MODEL IS
SHOWING A RAPID WEAKENING OF THE UPPER LEVEL SYSTEM...SO IT REMAINS
IN QUESTION HOW FAR EAST THE HEAVY SHOWERS WILL PROCEED AND HOW LONG
THEY WILL PERSIST. IN ANY CASE...YOUR NATIONAL WEATHER SERVICE WILL
BE WATCHING THESE DEVELOPMENTS...AND WARNINGS OR ADVISORIES WILL BE
ISSUED IF NEEDED.

WITH THE RAPID WEAKENING OF THE UPPER LEVEL SYSTEM...FORECAST MODELS
ARE ALSO WEAKENING THE SURFACE TROUGH OVER THE WESTERN END OF THE
STATE ON MONDAY. THIS SHOULD LEAD TO A RETURN OF WEAK TRADES
STATEWIDE BY LATE IN THE DAY MONDAY...WITH THE TRADES STRENGTHENING
TO 10 TO 20 MPH ON TUESDAY. FARRELL

.HFO...WARNINGS.....NONE
.      WATCHES......FLOOD FOR KAUAI AND OAHU ISSUED 9AM HST
.      ADVISORIES...NONE

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 heavy rain. Local standard time, as filed.

Heavy Rain, Honolulu

When
April 6, 1:55 PM HST to 5:30 PM HST
Where
Honolulu County, Kahana
Reported by
OFFICIAL NWS OBS.
Coordinates
21.455, -157.961 (the zone’s center; the record gives no point)

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

More

Every storm in Hawaii in 2003Every state in 2003This day in weather historyWarnings in Hawaii, April 2003

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: 5329326.