Heavy rain hammered parts of Windward O'ahu for most of yesterday, forcing police to close roads and prompting the National Weather Service to issue a flash flood warning last night.

Kamehameha Highway in Waikane flooded and was closed briefly before police opened a contraflow lane late last night.

There were also reports of flooding early last night at 'Aiali'i Place in 'Ahuimanu. But no other major problems were reported by public safety officials.

Lead weather forecaster Jeff Powell issued the flash flood warning shortly after 8:30 p.m. The warning was to have remain in effect until at least 11:30 p.m.

The 'Ahuimanu Loop rain gauge was the wettest recorded spot on O'ahu, with 7.88 inches of rain in the 24-hour period ending at 8 p.m. yesterday.

Poamoho in Central O'ahu as well as Windward sites Luluku and Waihe'e Pump each had more than 5 inches of rain in that period.

Nu'uanu and Manoa each had more than 2 inches of rain, and the showers had spread to Wai'anae late last night.

Conditions are expected to improve today with the return of trade winds.

Reach Rod Ohira at rohira@honoluluadvertiser.com.