Heavy Rain in Hawaii, April 1, 2004

Name: Heavy Rain in Hawaii, April 1, 2004
Start: 2004-04-01T16:05
End: 2004-04-01T17:35
Location: Hawaii

April 1, 2004 · NWS HFO · 1 event in 1 county or zone

Heavy showers caused drainage ditch and small stream flooding, and ponding of roadways at and near Ulupalakua on the Valley Isle of Maui. There were no reports of serious injuries or property damage.

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.

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Floods
Wind
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Cold
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Marine and coastal
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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 caused drainage ditch and small stream flooding, and ponding of roadways at and near Ulupalakua on the Valley Isle of Maui. There were no reports of serious injuries or property damage.

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 1, 4:00 PM HST, 5 minutes earlier.

Area forecast discussion, Apr 1, 4:00 PM HST, 5 minutes before

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU
400 PM HST THU APR 1 2004

.SYNOPSIS...SHOWER ACTIVITY WILL BE INCREASING FRIDAY AND SATURDAY...
 AND AGAIN DIMINISH SUNDAY.

&&

.DISCUSSION...ALTHO THE SHEARLINE HAS MADE ONLY SLOW PROGRESS TOWARD
 KAUAI SOME ISOLATED AFTERNOON CONVECTION HAS FORMED OVER WEST KAUAI
 ..SOUTH MAUI AND WEST BIG ISLAND THIS AFTERNOON...WE ARE ISSUING A
 SHORT TERM USSFA FOR ULUPALAKUA ON MAUI. OTHERWISE THE CONVERGENCE
 OF SHOWERS FROM THE APPROACHING SHEARLINE AND THE TRADE WIND SHOWER
 BAND FROM THE EAST BOTH ENHANCED FROM ABOVE BY AN UPPER LEVEL
 TROUGH WILL MAKE FOR SCATTERED SHOWERS THE NEXT TWO DAYS. THE
 UPPER TROUGH IS EXPECTED TO DEPART SUNDAY DIMINISHING SHOWERS
 CONSIDERABLY THEN. MEANWHILE OUR LIGHT TRADE WIND FLOW SHOULD FIRM
 BY TOMORROW AS SURFACE RIDGING TO THE NORTH STRENGTHENS.

&&

.MARINE...A HIGH SURF ADVISORY IS BEING ISSUED AT 4 PM. ALTHOUGH
 NORTHWEST BUOY OBSERVATIONS HAVE NOT BEEN AVAILABLE SINCE 9 AM
 MODELING INDICATE SURF WILL LIKELY REACH 15 FEET LATE TONIGHT AND
 TOMORROW MORNING.

&&

.WATCHES/WARNINGS/ADVISORIES...
 HIGH SURF ADVISORY...NORTHWEST FACING SHORES

MATSUDA

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, Maui

When: April 1, 4:05 PM HST to 5:35 PM HST
Where: Maui County, Ulupalakua
Reported by: OFFICIAL NWS OBS.
Coordinates: 20.868, -156.617 (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

Every storm in Hawaii in 2004 Every state in 2004 This day in weather history Warnings in Hawaii, April 2004

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: 5431465.