A flash flood warning has been issued for Oahu until 5:45 p.m.

At 2:40 p.m., radar showed heavy rain moving across Oahu from the south. Additional heavy rain is expected to move over the issland during the next several hours, the National Weather Service said.

At 3:40 p.m., it was raining heavily in leeward Oahu. Waianae Boat Harbor master William Aila said that squalls were moving through the area with winds that he estimated to be as firece as 50 mph.

There was also an unconfirmed report of a swift water rescue by an HFD helicopter on Waianae Valley Road.

A flash flood warning means that flash flooding is imminent or occurring in streams, roads and low-lying areas.

Police reported that some streets were being closed in the Wai'anae area due to flooding.

Police and fire communications crackled with reports of ponding on H-1 near Makakilo, and homes flooded or threatened with flooding on Upena Street in Makaha and on Farrington Highway.

A moist, unstable air mass just west of Kaua'i will continue to pose the threat of heavy showers across the western portion of the state, weather forecasters said.

Heavy rains on Thursday and again Friday night have saturated soil and additional heavy rain could quickly cause flooding, the weather service said.