Heavy rain, flash flooding to threaten entire state

A strong storm system will bring the potential for heavy rain, thunderstorms and flash flooding for the main Hawaiian islands starting Monday night through Wednesday, with a flash flood watch taking effect at 6 p.m. Monday and running through late Tuesday night.

The possibility of flash flooding is coming from a strong upper disturbance that will draw deep tropical moisture northward toward the state, which could produce heavy rainfall and possible flash flooding. The most intense rainfall and highest risk for flash flooding will start with Kauai to Oahu Monday evening, and then spread to Maui County and the Big Island Tuesday and Tuesday night.

There’s also a threat of strong and possibly damaging southerly winds for Kauai and Oahu, and a wind advisory may be posted soon. We’ll keep an eye out on that for you.

A small craft advisory is also posted for all Hawaiian waters due to the threat of storm conditions in coastal waters. Surf on north and west shores have fallen below advisory levels, but another north-northwest swell could boost waves back up late Tuesday and trigger another advisory. And after a long period of high surf for south shores, wave heights are returning to normal for the foreseeable future.