A powerful multi-day Kona storm is hitting Hawaii with its first heavy rains, reinvigorating the threat of major flooding as the state is still recovering from March’s devastating floods.
A flood watch is in effect across Hawaii through Friday afternoon, warning of the possibility of major flooding and landslides, as some places could record months’ worth of rain in just a few days. The storm is expected to dump 4 to 8 inches of rain over a wide area by Friday evening, with locally more than 10 inches possible.
The Big Island and Kauai are the most likely to see these higher rainfall accumulations, but depending on the progress of the storm, the heaviest rain bands could occur on any of the islands.
“Please prepare for possible evacuations. This is what we are expecting. This is an island-wide event,” Honolulu Mayor Rick Blangiardi said at a news conference Monday. The city of Honolulu will activate its emergency operations center on Wednesday, and first responders will be deployed to vulnerable areas ahead of the storm, he added.
The Kona Storm is a slow-moving weather system that forms and strengthens in the northwestern part of the island. They move slowly, harnessing moisture from the equatorial Pacific Ocean and focusing heavy rain on the state.
This is the third Kona storm to hit Hawaii since mid-March. The second flood caused the worst flooding in the state in 20 years, and many areas are still recovering. Widespread feet of rain fell across Oahu from March 19 to March 24, causing catastrophic flooding that required more than 200 rescues and damaged or destroyed hundreds of buildings. The first storm in mid-March caused severe flooding and wind damage in parts of Maui.
The worst-hit areas remain vulnerable to new flood threats as already saturated ground floods faster and flows into rivers more quickly.
“As far as we know, every bit of rain is now an inch or more of rain. Conditions are only going to make it worse and people need to be aware of that,” Blangiardi said.
The first showers of the storm began soaking the islands Tuesday afternoon and overnight. The heavy rains prompted flash flood warnings for parts of Maui and the Big Island.
Floodwaters invaded homes in the Puna area of the Big Island Tuesday night, according to a National Weather Service report citing emergency management. Several nearby stations reported rainfall totals of more than half a foot.
Showers and thunderstorms are expected to continue across Hawaii through Thursday morning, but will become stronger Thursday afternoon as the Kona storm strengthens.
A series of storms hitting the same area can dump huge amounts of rain in a very short period of time. One spot on Oahu recorded 25 inches of rain in March’s second Kona storm, most of it within 24 hours.
Rain is forecast for most of Hawaii into the weekend, but the intensity should taper off by Saturday as the storm moves northward and away from the islands.
