A flash flood watch is in effect tonight for Kauai, Oahu, and Molokai and widespread rain was possible over those islands, the National Weather Service said.

The watch is scheduled to expire at 6 a.m. Wednesday.

Earlier today, the weather service issued a flash flood warning for Oahu and said hail was possible for Kauai.

At about 5 p.m., rain was falling at a rate of 3 to 4 inches per hour in the most intense thunderstorms on Oahu, forecasters said. The flash flood warning for Oahu expired at 8:15 p.m.

On Kauai, torrential rainfall was occurring with frequent cloud-to-ground lightning.

A strong thunderstorm near Lihue had winds in excess of 30 mph and pea-sized hail was possible with the storm, forecasters said.

Throughout the day, Honolulu officials urged the public to stay indoors and off roadways as strong thunderstorms moved over Oahu.

Officials closed the Honolulu City Lights display and canceled all planned activities at Honolulu Hale tonight because of the bad weather, according to Mayor Kirk Caldwell’s office. The display is normally open until 11 p.m.

At 1:45 p.m. today, officials closed the Honolulu Zoo because of ponding on the walkways. Officials planned to decide Wednesday morning whether to reopen the zoo at its normal time of 9 a.m., Caldwell’s office said.

Heavy rainfall also resulted in brown water advisories for east and southeast shores of Oahu, Kailua and Lanikai beaches, and Nanakuli Beach Park, the state Department of Health said.

The public was advised to stay out of flood waters and storm water runoff due to possible overflowing cesspools, sewers, and manholes. Other possible pollutants included pesticides, animal fecal matter, dead animals, pathogens, chemicals and associated flood debris.

The city’s Department of Facility Maintenance cleared the mouth of Kaelepulu Stream at Kailua Beach at around noon in order to prevent flooding farther upstream, city spokesman Andrew Pereira said.

On Maui, a brown water advisory was in effect due to storm runoff.

On Wednesday, a cold front is expected to shift eastward across the state, improving conditions and decreasing showers.

Trade winds along with drier and more stable conditions are expected Thursday, with breezy weather through early next week.