Flash Flood, Honolulu
- When
- February 21, 5:30 PM HST to 9:50 PM HST
- Where
- Honolulu County, Kaaawa
- Reported by
- EMERGENCY MANAGER
- Coordinates
- 21.550, -157.867
Flash Flood in Hawaii, February 21, 2006
Showers and isolated thunderstorms drenched parts of Oahu and triggered flash flooding. A home was flooded in Kaaawa in windward Oahu by rapidly rising water; while in Kalihi in the southern part of the isle, the H-1 Freeway cutoff at Middle Street became impassable as rain water rose quickly in that area.
Where it happened
Every event with a place to put it. 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
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.
Showers and isolated thunderstorms drenched parts of Oahu and triggered flash flooding. A home was flooded in Kaaawa in windward Oahu by rapidly rising water; while in Kalihi in the southern part of the isle, the H-1 Freeway cutoff at Middle Street became impassable as rain water rose quickly in that area. Damage estimates were not available. No serious injuries were 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 Feb 21, 3:00 PM HST, 2 hours 30 minutes earlier.
Area forecast discussion, Feb 21, 3:00 PM HST, 2 hours 30 minutes before
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE HONOLULU HI 300 PM HST WED FEB 21 2006 .SYNOPSIS... HE THREAT OF HEAVY RAINS HAS BEEN EXTENDED FOR ANOTHER DAY AS A TROUGH OF LOW PRESSURE IS EXPECTED TO MOVE THROUGH THE ISLAND CHAIN WEDNESDAY AND WEDNESDAY NIGHT. LIGHT TRADES WITH BETTER WEATHER SHOULD BE RETURNING AFTER ITS PASSAGE AND LAST THROUGH THE WEEKEND. && .DISCUSSION... HAVE DECIDED TO ISSUE A SEVERE THUNDERSTORM WATCH FOR THE AREA WEST OF MOLOKAI INCLUDING OAHU AND KAUAI TIL 8 PM THIS EVENING. OTHERWISE NO DEVIATION TO THE FORECAST PHILOSOPHY. THE FLASH FLOOD WATCH WILL REMAIN IN EFFECT THROUGH WEDNESDAY MORNING. DID SOME MASSAGING TO THE GRIDS WHERE I BEEFED UP THE POPS AND INCLUDE ISOLATED THUNDERSTORMS WITH SOME OF THEM SEVERE WEST OF MOLOKAI TONIGHT. THE WINDS ARE UPDATED TO MATCH THE CURRENT PICTURE. THE DEEPENING TROUGH WEST OF KAUAI HAS CAUSED THE LOW LEVEL WINDS WEST OF MOLOKAI TO VEERED TO THE SOUTHEAST TO SOUTH-SOUTHWEST ALREADY. MODELS ARE A TAD BEHIND THIS. THE DYNAMICS DOES NOT TO BE AS STRONG TOMORROW AS TODAY WITH THE JET STREAM TAKES A MORE ZONAL ORIENTATION. SO THE FLASH FLOOD WATCH TIL NOON TOMORROW LOOKS OK. THE REMAINING ISLANDS HAVE NOT HAD MUCH SHOWERS. THEY SHOULD BE FINE EVEN WITH THE TROUGH MOVING THROUGH TOMORROW. THURSDAY MAY STILL HAVE SOME LINGERING MOISTURE BUT THE AIR MASS SHOULD BE MORE STABLE. LIGHT TRADES SHOULD BE RETURNING. ANOTHER FRONT NORTHWEST OF KAUAI WILL HOLD THE TRADES IN CHECK. THE TRADES WILL BE REINFORCED BY A LIGHT NORTHEAST WIND FLOW THURSDAY NIGHT AS THE DEPARTED TROUGH SPINS UP A LOW WELL EAST OF THE BIG ISLAND. WITH THE ISLANDS ON THE BACK SIDE OF THE LOW...THE WEATHER SHOULD BE DRIER STATEWIDE WITH COOL NORTHERLY WINDS. && .HFO WATCHES/WARNINGS/ADVISORIES... SEVERE THUNDERSTORM WATCH UNTIL 8 PM FOR KAUAI AND OAHU. FLOOD WATCH UNTIL NOON WEDNESDAY FOR KAUAI OAHU AND MOLOKAI. && LAU
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 flash flood. Local standard time, as filed.
What these are
- Flash Flood
- Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
The same day elsewhere
- Frost and Freeze in Oregon, February 21, 2006
- Blizzard in Alaska, February 21, 2006
- Flash Flood in Hawaii, February 21, 2006
- Heavy Rain in Hawaii, February 21, 2006
- Lake-Effect Snow in Michigan, February 21 to 22, 2006
- Heavy Rain in Hawaii, February 21, 2006
- Heavy Rain in Hawaii, February 21, 2006
- Heavy Rain in Hawaii, February 21 to 22, 2006
More
Every storm in Hawaii in 2006Every state in 2006This day in weather historyWarnings in Hawaii, February 2006
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: 5493101.