Update 7:30 a.m.

A flash flood watch remains in effect for all islands except Hawaii island.

The National Weather Service also issued a flash flood advisory for Oahu early today as radar indicated heavy showers over southeast side of the island with reports of a heavy downpour in downtown Honolulu. The adivsory is in effect through 9:45 a.m.

Forecasters say more heavy showers are moving north from the south due to a front near the main Hawaiian islands. The unstable weather could lead to thunderstorms.

The weather service warns the public to steer clear of streams and drainage ditches and to exercise caution while driving.

The flash flood watch is in effect until 6 p.m. today. An earlier flood advisory for the island of Maui was canceled.

5:15 a.m.

A flood advisory is in effect for the island of Maui through 8:15 a.m.

At 5 a.m., radar showed widespread rain over much of the Valley Isle, according to the National Weather Service.

A flash flood watch also remains in effect for Kauai, Niihau, Oahu, Kahoolawe, Lanai, Maui and Molokai through this afternoon.

10:15 p.m.

A flood advisory expired tonight for Oahu but a flash flood watch remains for Kauai, Niihau and Oahu through Monday afternoon.

8:30 p.m.

A flood advisory is in effect for Oahu until 10:15 tonight.

Radar indicated heavy rain on the Waianae coast this evening. Rain was falling at a rate of one and a half inches per hour, according to the National Weather Service. Radar also indicated more heavy rain west and southwest of Oahu.

A flash flood warning for Kauai has been canceled but a flash flood watch remains in effect. Kuhio Highway near the Hanalei Bridge is now open with one lane of alternating traffic. Motorists are advised to drive with caution and to allow for extra travel time. The Red Cross also closed its shelter at Hanalei Elementary School.

6:45 p.m.

A flash flood warning is in effect for Kauai and Hanalei Elementary School is now open as a Red Cross Shelter.

Kuhio Highway at the Hanalei Bridge is closed due to flooding. Runoff from earlier heavy rains will keep stream levels elevated.

Kauai residents can call 241-1725 for road conditions and closures.

3:33 p.m.

A flash flood watch for Kauai, Niihau and Oahu has been extended to Monday afternoon.

The watch was also widened to cover Maui, starting this evening and lasting until Monday afternoon.

Heavy showers and thunderstorms were expected to develop and move over the western end of the state today as a front moves down the island chain, the weather service said.

Torrential rainfall and flash flooding in poor drainage areas, streams, and low-lying areas were possible.

Flash flooding will be possible over Niihau, Kauai, and Oahu today through Monday and over Maui from tonight, the weather service said.

The flash flood watch for Maui includes Kahoolawe, Lanai, and Molokai.

11:35 a.m.

The National Weather Service canceled a flash flood warning for the island of Kauai, however a flash flood watch is still in effect. A special marine warning for the island is still in effect until noon.

Radar at 10:32 a.m. showed strong thunderstorms capable of producing gusty winds and water spouts located about 32 miles west of Lehua Rock, moving east at 28 mph.

Previous coverage

The National Weather Service this morning upgraded a flash flood advisory for the island of Kauai to a flash flood warning until 10 a.m.

Doppler radar at 7:04 a.m. showed heavy rain falling at a rate of 2 to 3 inches per hour developing over Lihue and Wailua and the heaviest rainfall near Anahola and Kapahi.

Widespread rain is expected to continue over many parts of Kauai along with a rapid rise in rivers and streams.

The warning may be extended if heavy rainfall continues.

A special marine warning was also issued for Kauai until 9 a.m.

Radar at 6:57 a.m. showed an area of strong thunderstorms capable of producing waterspouts over Kukuiula Harbor moving west at 28 mph.

Waterspouts can easily overturn boats and strong winds could damage small crafts.

Officials are urging the public not to cross fast flowing water in a vehicle or on foot.