Rain continues to fall this afternoon, but "we're seeing an improving trend across the island, for a lot of areas on O'ahu," National Weather Service hydrologist Kevin Kodama said at 1:30 p.m.

Kodama urged O'ahu residents to take seriously the extension of a flash flood warning until 4:15 p.m.

Despite slowed rainfall, "the warning was extended one more time, because there's still quite a bit of runoff in streams" that could cause additional flooding, Kodama said.

Lake Wilson's water level was 83 feet, which means three feet of water is running over the spillway, Kodama said.

At 1:30 p.m., the heaviest showers had moved off O'ahu and started to hit Maui and even the Kona side of the Big Island but the system has weakened and may not deal as heavy a blow to those islands, Kodama said.

Maui County is under a flood advisory and flash flood watch until further notice.

"The system as whole has weakened and the parent system far to the Northwest is starting to move away," Kodama said.

Rainfall on O'ahu was heaviest between 5 a.m. and 8 a.m., Kodama said, with resulting flooding varying according to rainfall and the terrain it falls upon.

Kaua'i had some locally heavy rain, but nothing outside the ordinary, he said.

Kodama called today's rain "the most significant event for this wet season" (October-May), noting most of the rainfall occurred within 12 hours.

"There were several places that received 10-plus inches," Kodama said.

"Anytime you get over an inch per hour, that gets your attention. Once it's above 3-4 inches per hour, that's when it can cause problems pretty quickly."

The National Weather Service is predicting frequent showers and isolated thunderstorms for O'ahu through the afternoon, with wind from the South at 20-30 mph and gusts to 45 mph.

Tonight, O'ahu can expect some locally heavy rainfall and south winds 15 to 25 mph.