Oahu and the rest of the state are under a flash flood watch through Sunday because of the potential for heavy rains.

National Weather Service forecaster John Bravender said heavy rains fell today on the Big Island, with Kalapana receiving 5.6 inches in a 24-hour period ending 8 a.m. and Pahoa 2.6 inches of rainfall in 24 hours ending 2 p.m.

A weather system is destabilizing the atmosphere and enhancing the usual tradewind showers with the threat of heavy rains and thunderstorms through this afternoon and likely through Saturday, the Weather Service said.

The weather is expected to be sunny in the early afternoon and then partly sunny through the rest of today, with windward and mauka areas experiencing numerous showers and isolated thunderstorms in the late afternoon.

Leeward areas are expected to have scattered showers and isolated thunderstorms late this afternoon.

Heavy rainfall is possible in the late afternoon, with high temperatures ranging from 78 to 84 degrees, tradewinds 10 to 20 mph with higher gusts.

Tonight, the weather is expected to be mostly cloudy with numerous showers and isolated thunderstorms in windward and mauka areas.

In leeward areas, residents can expect scattered showers and isolated thunderstorms, with temperature ranging from 68-74 degrees and tradewinds 10 to 15 miles an hour and gusty.

On Saturday and Sunday, the weather is expected to be mostly cloudy, with windward and mauka areas experiencing numerous showers and a slight chance of thunderstorms. The rains will eventually subside with occasional showers.

Scattered showers with a slight chance of thunderstorms are expected in leeward areas during the day, along with possibly heavy rainfall. The high temperatures will range from 78 to 84 and lows, 68-74, with winds 10 to 20 mph and gusty.

For Monday and Tuesday, the weather is expected to be mostly cloudy, with occasional showers in the windward and mauka areas and scattered showers in leeward areas. The high temperatures will range from 78 to 83, and lows, 69 to 74, with wind 15 to 20 mph.

The high at Honolulu International Airport was 86 degrees on Thursday, and this morning’s low was 75.

Sunset today is at 5:55 p.m., with sunrise at 6:37 a.m. Saturday.