Update: Greatest chance of severe storms during daytime, through evening Friday

Update at 5:25 p.m. May 9: The National Weather Service is now forecasting the greatest chance for severe thunderstorms associated with an unusually strong upper level disturbance moving over Hawai‘i will be during the day and through the evening Friday.

Any strong or severe storms that develop could produce damaging winds and large hail.

Heavy showers and isolated thunderstorms are also in the forecast from tonight through Friday night. The heaviest downpours will be hit or miss, but where they do happen, they will be capable of producing more than 3 inches of rainfall per hour.

A threat for flash flooding is expected to be the greatest Friday through Friday evening. A flood watch is in effect for the entire state until 6 a.m. Saturday.

Original post from 2:34 p.m. May 9: An unusually strong upper-level disturbance is moving across the Hawaiian Islands tonight through Saturday, bringing high surf and a flood watch.

A high surf advisory has been issued for south-facing shores with surf expected to reach 7 to 10 feet during the next several days.

Additionally, the National Weather Service in Honolulu reports the weather system is bringing scattered heavy showers and isolated thunderstorms tonight through Friday and Friday night.

The heaviest downpours will be hit or miss, but where they do occur, they will be capable of producing rainfall rates over 3 inches per hour. The threat of flash flooding is expected to be the greatest Friday through Friday evening.

Conditions should steadily improve from west to east late Friday into Saturday.