Flash Flood in Honolulu County, Hawaii

Heavy rain fell over the Koolau mountain range in the middle to later half of the morning, then a thunderstorm developed and anchored itself over the mountains. This thunderstorm then produced a large amount of rain in a short time frame, quickly overwhelming Manoa Stream and sending a flood surge down towards Manoa Valley. Manoa marketplace had nearly 2 feet of water and parked cars were inundated. Homes in Manoa reported flooding and an excavation site quickly became overwhelmed with water and sent mud and debris down the road. The overflowing Manoa and Palolo Streams inundated the entire campus of Hokulani Elementary School in St. Louis Heights and students were evacuated. Large boulders and debris were observed across many roads in Manoa Valley and flooding was also observed across the upper portion of the University of Hawaii at Manoa campus. A home was also flooded in Laie.

A cutoff low moved in from the northwest and pulled deep tropical moisture from the south over the Hawaiian islands. This led to the development of prolonged slow moving heavy rain and thunderstorms. The heavy rain and thunderstorms caused catastrophic flooding over Oahu's North Shore and Manoa Valley.