Name: Heavy Rain in Hawaii, December 26 to 27, 2004
Start: 2004-12-26T22:12
End: 2004-12-27T02:20
Location: Hawaii

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 western and central sections of Oahu. However, there were no serious injuries or property damage 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 Dec 26, 9:08 PM HST, 1 hour 4 minutes earlier.

Area forecast discussion, Dec 26, 9:08 PM HST, 1 hour 4 minutes before

HAWAIIAN ISLANDS FORECAST DISCUSSION
NATIONAL WEATHER SERVICE HONOLULU HI
908 PM HST SUN DEC 26 2004

SYNOPSIS...
A SLOW MOVING COLD FRONT WILL BRING WET WEATHER TO MAINLY THE
SMALLER ISLANDS TONIGHT AND MONDAY. LINGERING MOISTURE OVER THE
STATE...AND AN UPPER TROUGH TO OUR WEST...MAY KEEP THE WEATHER
SOMEWAT UNSETTLED THROUGH MUCH OF THE WEEK. A STRONG COLD FRONT MAY
BRING GUSTY KONA WINDS AND POSSIBLY STORMY WEATHER BY NEW YEARS EVE.

&&

.UPDATE...
HAVE UPDATED THE GRIDS TO PLACE THUNDERSTORMS IN THE FORECAST FOR
OAHU AND PORTIONS OF MAUI COUNTY AS WELL. VIGOROUS SHORTWAVE
ROTATING AROUND THE BASE OF THE UPPER TROUGH...ACCOMPANIED BY A 110
MILE WIDE BAND OF SHOWERS AND THUNDERSTORMS THAT IS PUSHING STEADILY
EASTWARD. REMAINDER OF THE FORECAST IS UNCHANGED AND THE PREVIOUS
DISCUSSION FROM 4 PM FOLLOWS.

&&

.PREV DISCUSSION...
THE GFS MODEL RUN KEEPS SHOWERS OVER KAUAI AND OAHU THROUGH
MONDAY...AND SPREADS THEM TO THE OTHER ISLANDS TUESDAY AND
WEDNESDAY. ANOTHER FRONT BRINGS IN MORE WIDESPREAD SHOWERS THURSDAY
AND FRIDAY...ALONG WITH ENOUGH INSTABILITY TO ASSURE THE BIG ISLAND
OF SOME THUNDERSTORMS AS WELL.

AT THE MOMENT...SATELLITE IMAGERY A BAND OF HEAVY SHOWERS AND
THUNDERSTORMS ALONG 160W. THIS BAND MARKS THE LEADING EDGE OF A COLD
FRONT NORTH OF 20N...WITH CONVERGENCE OF TROPICAL MOISTURE SOUTH OF
20N. OTHER AREAS OF SCATTERED SHOWERS CAN BE SEEN OVER THE WATERS
AROUND THE ISLANDS. THE SHOWERS AND THUNDERSTORMS OVER AND AROUND
KAUAI WILL MOVE EAST TONIGHT...TO OAHU AT LEAST.

A BROAD SURFACE RIDGE LIES OVER THE CENTRAL ISLANDS AND IS
RESPONSIBLE FOR KEEPING GENERALLY EASTERLY TO SOUTHEAST WINDS OVER
THE BIG ISLANDS...AND SOUTHEAST WINDS OVER THE STATE FROM MAUI TO
OAHU. THE FRONT WEST OF KAUAI HAS TURNED WINDS THERE MORE SOUTHERLY.
COMPUTER FORECAST MODELS BRING THIS FRONT TO KAUAI TONIGHT...THEN
WEAKEN IT INTO A SURFACE TROUGH OVER THE WESTERN ISLANDS MONDAY AND
TUESDAY. THUS AT LEAST THE ISLANDS OF KAUAI AND OAHU ARE IN STORE
FOR SHOWERS...WITH CHANCE FOR A THUNDERSTORM AROUND KAUAI...THROUGH
MONDAY. THESE MODELS ALSO BRING TROPICAL MOISTURE FROM SOUTH OF THE
STATE UP OVER THE ISLANDS TUESDAY AND WEDNESDAY...THUS THE CHANCE
FOR SHOWERS EXISTS ON ALL ISLANDS THROUGH MIDWEEK.

THE NEXT LOW PRESSURE SYSTEM AND ITS ASSOCIATED FRONT IS FORECAST TO
MAKE ITS PRESENCE KNOWN TO THE ISLANDS AS EARLY AS LATE WEDNESDAY BY
TURNING WINDS SOUTHERLY STATEWIDE. THESE WINDS WILL INCREASE
SIGNIFICANTLY AHEAD OF THIS COLD FRONT THURSDAY NIGHT AND FRIDAY...
INTRODUCING THE LIKELIHOOD OF WIND ADVISORIES FOR THE NORMALLY
WINDWARD SIDES OF THE ISLANDS...AND HIGH WIND WARNINGS FOR THE BIG
ISLAND SUMMITS. THIS SYSTEM WILL ALSO BRING A MORE SIGNIFICANT
POTENTIAL FOR HEAVY SHOWERS AND THUNDERSTORMS...ESPECIALLY NEAR THE
BIG ISLAND...AS IT BRINGS INSTABILITY TO THE STATE NEW YEARS EVE.
ANOTHER POWERFUL SYSTEM BEHIND THIS ONE WILL CONTINUE THE WINDS AND
WET WEATHER ON NEW YEARS DAY...WITH AN UNUSUAL BOUT OF BRISK
WESTERLY WINDS CONTINUING THROUGH THE END OF THE FORECAST PERIOD.

&&

.HFO WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

R BALLARD

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: December 26, 10:12 PM HST to December 27, 2:20 AM HST
Where: Honolulu County, Waianae
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 2004 Every state in 2004 This day in weather history Warnings in Hawaii, December 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: 5431564.