Hawaii, 2004

Heavy Rain in Hawaii, August 4, 2004

August 4, 2004 · NWS HFO · 1 event in 1 county or zone

Heavy showers and isolated thunderstorms produced ponding or roadways, and small stream and drainage ditch flooding over the western half of Molokai. There were no reports of serious injuries or property damage.

Where it happened

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  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
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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 and isolated thunderstorms produced ponding or roadways, and small stream and drainage ditch flooding over the western half of Molokai. 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 Aug 4, 4:00 AM HST, 35 minutes earlier.

Area forecast discussion, Aug 4, 4:00 AM HST, 35 minutes before
HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
400 AM HST WED AUG 4 2004

.SYNOPSIS...
THE REMNANT TROPICAL MOISTURE FROM TROPICAL STORM DARBY REMAINS OVER
THE MAIN HAWAIIAN ISLANDS THIS MORNING. HEAVY SHOWERS AND
THUNDERSTORMS WILL BE MOVING OVER THE ISLANDS TODAY...AND
CONTINUING OVER KAUAI TONIGHT. TRADE WINDS...WITH THEIR MORE NORMAL
PATTERN OF WINDWARD AND MAUKA...NIGHT AND MORNING SHOWERS...WILL
RETURN ON THURSDAY.

&&

.DISCUSSION...
HEAVY SHOWERS CONTINUE TO MOVE UP OVER OAHU...MOLOKAI AND LANAI
FROM THE SOUTH THIS MORNING...WHILE KAUAI IS SEEING HEAVY SHOWERS
AND THUNDERSTORMS MOVING IN FROM THE EAST. THE DIVIDING LINE BETWEEN
SOUTH OR SOUTHEAST WINDS AND EAST OR NORTHEAST WINDS IS A SURFACE
TROUGH OF LOW PRESSURE...NOW LOCATED IN THE KAUAI CHANNEL. A TROUGH
OF LOW PRESSURE IN THE UPPER ATMOSPHERE TO THE WEST OF KAUAI IS
KEEPING THE ATMOSPHERE OVER THE HAWAIIAN ISLANDS AND THE REMNANT
TROPICAL MOISTURE UNSTABLE...AND THIS IS PROMPTING THE CONVECTION
OVER THE STATE. THE TROUGH AND SHOWERS ARE MOVING WESTWARD AT ABOUT
7 MPH...AND WILL CONTINUE TO AFFECT THE ISLANDS FROM KAUAI TO
MOLOKAI THROUGH THE DAY. BY THURSDAY AND FRIDAY MORE TYPICAL TRADE
WIND WEATHER IS EXPECTED THANKS TO HIGH PRESSURE FAR NORTH OF THE
STATE. TRADE WINDS WILL BE IN THE 10 TO 20 MPH RANGE WITH SHOWERS
MAINLY CONFINED TO WINDWARD AND MAUKA AREAS.

&&

.LONG TERM...
WE ARE ALSO WATCHING ANOTHER AREA OF SHOWERY WEATHER THAT MAY
APPROACH THE ISLANDS OVER THE WEEKEND. TROPICAL DEPRESSION SIX-E IS
LOCATED ABOUT 1500 MILES EAST SOUTHEAST OF HONOLULU. THE NATIONAL
HURRICANE CENTER IN MIAMI HAS ISSUED ITS LAST ADVISORY ON THIS SYSTEM
BUT THE GFS AND NOGAPS MODELS STILL BRING A LARGE AREA OF REMNANT
TROPICAL MOISTURE OVER THE STATE LATE FRIDAY INTO SATURDAY BRINGING
THE THREAT OF HEAVY RAINFALL ONCE AGAIN TO THE STATE.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH ALL ISLANDS.
HIGH SURF ADVISORY EAST SHORES OF KAUAI OAHU MOLOKAI MAUI AND THE
BIG ISLAND.

&&

FARRELL

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
August 4, 4:35 AM HST to 8:27 AM HST
Where
Maui County, Maunaloa
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

More

Every storm in Hawaii in 2004Every state in 2004This day in weather historyWarnings in Hawaii, August 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: 5431602.