The National Weather Service allowed a flood advisory for Oahu to lapse at 11 a.m., but forecasters are keeping a close watch on Wilson Reservoir in Wahiawa.

The water level had reached the 82-foot level, and water over-tops the dam spillway when the level hits 84-feet , forecaster Eric Lau said.

When water over-topped the spillway two weeks ago during a driving rainstorm, flood waters tore through Otake Camp downstream, damaging dozens of houses.

Heavy showers that dumped an inch or two of rain over Central Oahu earlier today have dissipated, but unstable air over most of the state still posses a threat, Lau said.

A low pressure area causing the unstable air mass is expected to clear the state by later tonight, Lau said.

As the morning wore on, communities along the Windward side of the Koolau Range were being pelted by heavy rain, Lau said.

There had been no reports of flooding as of 11:15 a.m.