Heavy Rain, Honolulu
- When
- July 22, 7:31 PM HST to 9:02 PM HST
- Where
- Honolulu County, 5.39 mi NNE of Whitmore Village to 0.93 mi NNW of Niu Valley
- Reported by
- Official NWS Observations
- Coordinates
- 21.589, -157.990
Heavy Rain in Hawaii, July 22, 2013
The combination of low level moisture, and surface and upper troughs in the area, triggered heavy rain over the Koolau Range on Oahu. The downpour produced small stream and drainage ditch flooding, and ponding on roadways.
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.
The combination of low level moisture, and surface and upper troughs in the area, triggered heavy rain over the Koolau Range on Oahu. The downpour produced small stream and drainage ditch flooding, and ponding on roadways. However, no serious injuries or property damage 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 Jul 22, 7:00 PM HST, 31 minutes earlier.
Area forecast discussion, Jul 22, 7:00 PM HST, 31 minutes before
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE HONOLULU HI 700 PM HST MON JUL 22 2013 .UPDATE... UPDATED SYNOPSIS. && .SYNOPSIS... A TROUGH WILL PRODUCE SHOWERS ON OAHU AND KAUAI...AND MUGGY WEATHER ON THE OTHER ISLANDS THROUGH TOMORROW. STRONGER TRADE WINDS AND MORE SETTLED WEATHER WILL RETURN FOR THE SECOND HALF OF THE WEEK. && .PREV DISCUSSION.../ISSUED 645 PM HST MON JUL 22 2013/ A SURFACE TROUGH AXIS IS LOCATED JUST WEST OF OAHU LATE THIS AFTERNOON...WHILE A RIDGE TO THE NORTHEAST IS DRIVING GENTLE TO MODERATE WINDS ACROSS THE AREA. FLOW IS GENERALLY FROM THE EAST...HOWEVER THE TROUGH IS CAUSING SOME VARIABILITY IN THE WIND DIRECTION ACROSS THE WESTERN SIDE OF THE STATE...AND WILL CONTINUE THROUGH TOMORROW. AS THE TROUGH PASSES OVER KAUAI TONIGHT...EXPECT TO SEE A SMALL INCREASE IN SHOWERS OVERNIGHT AND INTO THE DAY TUESDAY FOR THE GARDEN ISLE...MAINLY WINDWARD AND MAUKA AREAS. FOR THE OTHER ISLANDS... EXPECT TO SEE A TURN TO MORE STABLE CONDITIONS BEGINNING TONIGHT. A SLOW DRYING TREND IS EXPECTED TUESDAY AS WEAK TRADES BEGIN TO CARRY THE MOISTURE AND CLOUDS WEST OF THE ISLAND CHAIN. TRADES WILL STRENGTHEN TO MODERATE TO FRESH BREEZES ON WEDNESDAY ALLOWING ATMOSPHERIC CONDITIONS TO BE DRIER AND MORE STABLE THROUGH THE REST OF THE WEEK. SCATTERED CLOUDS AND LIGHT SHOWERS WILL FOCUS ON WINDWARD SLOPES...WITH LEEWARD AREAS KEEPING MOSTLY SUNNY CONDITIONS. THE TRADE WINDS LOOK TO WEAKEN A BIT ON SUNDAY. A WEAKENING SURFACE TROUGH IS EXITING THE AREA THIS EVENING. CONDITIONS WILL IMPROVE THIS EVENING WITH ONLY ISOL MVFR CONDITIONS ALONG THE WINDWARD SLOPES AS LIGHT TO MODERATE TRADE WINDS CONTINUE. SMALL TO MODERATE...LONG PERIOD SOUTH SWELL WILL CONTINUE THROUGH THE WEEK. SURF HEIGHTS WILL REMAIN BELOW ADVISORY CRITERIA. NO OTHER SIGNIFICANT SWELLS ARE EXPECTED. TRADE WINDS WILL STRENGTHEN BEGINNING ON WEDNESDAY. WINDY PORTIONS AROUND MAUI AND BIG ISLAND MAY GO UNDER A SMALL CRAFT ADVISORY AT THAT TIME. && .HFO WATCHES/WARNINGS/ADVISORIES... NONE. && UPDATE...DONALDSON PREV DISCUSSION/MARINE...FOSTER AVIATION...MORRISON
The radar
The national radar mosaic for the moment the first event began.
Event by event
1 heavy rain. Local standard time, as filed.
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
- Hail and Damaging Winds in Iowa, July 22, 2013
- Hail and Damaging Winds in Kansas, July 22, 2013
- Hail and Damaging Wind in Wyoming, July 22, 2013
- Flash Flooding and Flood in New Jersey, July 22 to 23, 2013
- Tornado and Flash Flooding in Florida, July 22, 2013
- Hail and Damaging Winds in Wisconsin, July 22, 2013
- Flash Flooding in New York, July 22, 2013
- Hail and Damaging Winds in Arkansas, July 22, 2013
- Hail in Wyoming, July 22, 2013
- Hail in South Dakota, July 22, 2013
- Tornado and Hail in Wisconsin, July 22, 2013
- Flood in Pennsylvania, July 22, 2013
More
Every storm in Hawaii in 2013Every state in 2013This day in weather historyWarnings in Hawaii, July 2013
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: 461676.