UPDATE: 9 p.m.

The flood watch for Oahu has expired.

5 p.m.

The flood advisory for Kauai has expired, but the flood watch for Oahu remains in place until 6 a.m. Friday, according to the National Weather Service.

Forecasters said thunderstorms and locally heavy showers will remain possible through tonight for the central islands.

“A drier and more settled trade wind weather pattern is expected as the weekend begins, with limited showers expected into early next week as trade winds gradually turn to the southeast and diminish Sunday and Monday,” the weather service said.

3 p.m.

A flood watch for Oahu has been extended until 6 a.m. Friday. The National Weather Service said heavy showers and thunderstorms will continue to be possible over Oahu through tonight, bringing periods of heavy rainfall to both leeward and windward communities.

2:20 p.m.

The National Weather Service warned that a strong line of thundershowers with strong winds and hail is moving over Kauai.

In a special weather statement issued at 2:08 p.m.. forecasters said, “At 2:06 p.m, Doppler radar was tracking a line of strong thunderstorms over central and eastern Kauai, moving east at 15 mph.”

They said residents should expect winds in excess of 40 mph and pea-size hail.

“This storm will remain over sparsely populated areas of Kauai in Kauai County, including the following locations: Puhi, Kaumakani, Kealia, Kalihiwai, Pakala Village, Hanamaulu, Wailua River State Park and Eleele,” the statement said.

“If outdoors, consider seeking shelter inside a building,” forecasters said, “Frequent cloud-to-ground lightning is occurring with this storm. Lightning can strike 10 miles away from a thunderstorm. Seek a safe shelter inside a building or vehicle.” The weather statement was in effect until 2:30 p.m.

The island remains under a flood advisory, and Oahu is still under a flood watch.

1:30 p.m.

A flood advisory is in effect for Kauai until 4:15 p.m., NWS said.

Radar data at 1:09 p.m. indicated heavy rain moving into western Kauai, with rainfall rates estimated at 1 to 2 inches per hour. Forecasters expect the rain to drift over the island over the next couple of hours.

Locations that will experience flooding include Lihue, Kapaa, Kalaheo, Kekaha, Princeville, Kilauea, North Fork Wailua Trails, Lawai, Omao, Kokee State Park, Wailua Homesteads, Hanalei, Hanapepe, Wainiha, Na Pali State Park, Koloa, Haena, Waimea, Wailua and Poipu.

Officials urge the public to stay away from streams, drainage ditches and low lying areas prone to flooding.

PREVIOUS COVERAGE

Oahu is under a flood watch through this afternoon with heavy rains and thunderstorms expected to move over the islands, the National Weather Service said.

Lightning, thunder and hail struck Oahu overnight as the storm system reached the island.

“Several rounds of slow-moving heavy showers and thunderstorms are expected to move over Oahu from the south today, bringing periods of heavy rainfall to both leeward and windward communities,” forecasters said this morning.

“Flood prone roads and other low lying areas may be closed due to elevated runoff and overflowing streams,” they said. “Urban areas may receive more significant flooding and property damage due to rapid runoff.”

Forecasters urge the public not to cross fast-flowing water in a vehicle or on foot.

Early this morning the weather service said hail of about a quarter-inch in diameter was reported in Nanakuli and Wahiawa after midnight.

Thunderstorms and locally heavy showers are possible for all islands today but especially for Kauai and Oahu, forecasters said.

After today, they said, “light winds and humid conditions will prevail through Friday.”

“A drier and more settled trade wind weather pattern is expected as the weekend begins, with limited showers expected into early next week as trade winds gradually turn to the southeast and diminish Sunday and Monday,” the forecast said. “Light winds and increased moisture are anticipated again during the middle part of next week.”