A high surf warning for the North Shore and a high surf advisory for the Waianae Coast has been extended until noon Saturday, the city Department of Emergency Management said.

The advisories were issued due to a northwest swell forecast to bring surf up to 25 feet high, according to the National Weather Service.

A combination of large surf, strong west and northwest winds and higher than normal high tides could lead to overwash onto roadways typically vulnerable along west- and north-facing shores at or around the times of high tide through early Saturday, Emergency Management said.

A separate, northeast swell is believed to be subsiding and a high surf advisory issued earlier for east-facing shores was cancelled at 4 a.m.