Heavy Rain in Hawaii, September 10 to 11, 2003

Name: Heavy Rain in Hawaii, September 10 to 11, 2003
Start: 2003-09-10T20:45
End: 2003-09-11T08:45
Location: Hawaii

September 10 to 11, 2003 · NWS HFO · 1 event in 1 county or zone

Heavy showers caused ponding of roadways, and drainage ditch and stream flooding in eastern and southern parts of Oahu. However, there were no reports of serious property damage or injuries.

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 caused ponding of roadways, and drainage ditch and stream flooding in eastern and southern parts of Oahu. However, there were no reports of serious property damage or injuries.

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 Sep 10, 8:15 PM HST, 30 minutes earlier.

Area forecast discussion, Sep 10, 8:15 PM HST, 30 minutes before

HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
815 PM HST WED SEP 10 2003

SUMMARY...THE PROXIMITY OF THE SUBTROPICAL RIDGE WILL KEEP WINDS
LIGHT FROM THE EAST TO SOUTHEAST THROUGH FRIDAY AFTERNOON. MODERATE
TRADES WILL RETURN BY SATURDAY AS THE RIDGE REBOUNDS NORTHWARD. THE
CURRENT PATTERN OF AFTERNOON AND EVENING CLOUDS AND SHOWERS WILL
GIVE WAY TO A TRADE WIND DISTRIBUTION OF NIGHT AND MORNING CLOUDS
AND SHOWERS OVER WINDWARD AND MAUKA AREAS.

DISCUSSION...A COLD FRONT APPROACHING FROM THE NORTHWEST WILL STALL
FAR FROM THE MAIN ISLANDS...BUT IT HAS PUSHED THE SUBTROPICAL RIDGE
FAR ENOUGH SOUTH AHEAD OF IT TO FLATTEN THE PRESSURE GRADIENT AND
DECREASE OUR TRADES. WINDS BECAME SUFFICIENTLY LIGHT THIS AFTERNOON
FOR SEA BREEZES TO FORM...BEGINNING A PATTERN OF CLOUDY AND SHOWERY
MAUKA WEATHER WHICH WILL RECUR EACH AFTERNOON AND EVENING THROUGH
FRIDAY.

AS THE SURFACE COLD FRONT STALLS...WEAKENS...THEN LIFTS TO THE NORTH
BY THE WEEKEND...HIGH PRESSURE WILL FILL BACK IN FROM THE NORTHEAST.
THIS WILL PUSH THE SUBTROPICAL RIDGE BACK UP TO NEAR 30N AND RESTORE
THE PRESSURE GRADIENT NEEDED TO SUSTAIN 10 TO 20 MPH TRADE WINDS.

MODERATE TRADE WINDS WILL RETURN SATURDAY...BUT MODELS SHOW AN UPPER
TROUGH WILL REMAIN JUST WEST OF THE MAIN ISLANDS THROUGH THE
FORECAST PERIOD. THIS LIKELY MEANS THAT THE RETURNING TRADE PATTERN
WILL BE WETTER THAN USUAL...GIVEN THE DESTABILIZING EFFECTS OF THESE
UPPER AIR FEATURES. MOISTURE BROUGHT IN BY THE RETURNING TRADES
WILL PROVIDE SCATTERED SHORES FOR WINDWARD AND MAUKA AREAS THROUGH
THE WEEKEND AND INTO THE NEXT WORK WEEK.

THIS UPPER TROUGH WILL ALSO KEEP SKIES CLOUDY AND SHOWERY THIS
EVENING UNTIL AT LEAST MIDNIGHT AND LIKELY LONG AFTER.

POWELL

.HFO...WARNINGS...WATCHES...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: September 10, 8:45 PM HST to September 11, 8:45 AM HST
Where: Honolulu County, Laie
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

Every storm in Hawaii in 2003 Every state in 2003 This day in weather history Warnings in Hawaii, September 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: 5327729.