Flood in Hawaii, May 18, 2001

Name: Flood in Hawaii, May 18, 2001
Start: 2001-05-18T20:15
End: 2001-05-18T22:50
Location: Hawaii

May 18, 2001 · NWS HFO · 1 event in 1 county or zone

Heavy showers caused ponding of roadways and minor stream and drainage ditch flooding in windward areas of Oahu. There were no reports of injuries or serious 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.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

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 minor stream and drainage ditch flooding in windward areas of Oahu. There were no reports of injuries or serious 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 May 18, 7:31 PM HST, 44 minutes earlier.

Area forecast discussion, May 18, 7:31 PM HST, 44 minutes before

HAWAIIAN ISLANDS SYNOPTIC DISCUSSION AND GUIDANCE
NATIONAL WEATHER SERVICE HONOLULU HI
830 PM HST FRI MAY 18 2001

SUMMARY...OUR LIGHT WIND SITUATION WILL CONTINUE THROUGH THE
WEEKEND. A FEW BY AFTERNOON...WITH A SHOWERS DEVELOPING AGAIN MAINLY
OVER MOUNTAIN AND INTERIOR SECTIONS THROUGH THE EVENING HOURS. SOME
SHOWERS MAY BE BRIEFLY HEAVY.

DISCUSSION...THE PRESENCE OF A TROUGH NORTHWEST OF THE ISLANDS...AT
THE SURFACE AND ALOFT...WILL KEEP WINDS LIGHT THROUGH THE WEEKEND
AND POSSIBLY INTO EARLY NEXT WEEK. THIS WIND PATTERN OVER THE
ISLANDS WILL PROMOTE CONVECTIVE WEATHER DURING THE DAYTIME HOURS...
WITH CLEARING SKIES AT NIGHT. WITH THE ISLANDS ON THE WEST OR
SOUTHWEST SIDE OF AN UPPER LOW...TEMPERATURES ALOFT WILL NOT
GENERALLY PRODUCE DEEP CONVECTION. BUT WITHOUT PERSISTANT SUBSIDENCE
OVERHEAD...ANY TRADE WIND OR SUBSIDENCE INVERSIONS WILL BE WEAK OR
NON-EXISTANT...SO SOME HEAVY SHOWERS CAN BE EXPECTED DESPITE THE
RELATIVELY MODERATE STABILITY INDICES. THESE ARE NOT EXPECTED TO BE
LONG-LASTING AT THIS TIME SO NO WATCHES ARE CURRENTLY BEING POSTED.
A SOUTH SWELL IS CURRENTLY AFFECTING ALL SOUTH FACING SHORES...AND
THIS SWELL WILL CONTINUE THROUGH SATURDAY. FARRELL

.PHFO......WARNINGS.....NONE
.          WATCHES......NONE
.          ADVISORIES...HIGH SURF SOUTH SHORES

The radar

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

Open the radar archive at this moment

Event by event

1 flood. Local standard time, as filed.

Flood, Honolulu

When: May 18, 8:15 PM HST to 10:50 PM HST
Where: Honolulu County, Kaneohe
Reported by: OFFICIAL NWS OBS.
Coordinates: 21.455, -157.961 (the zone’s center; the record gives no point)

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Hawaii in 2001 Every state in 2001 This day in weather history Warnings in Hawaii, May 2001

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: 5244186.