A high surf warning is in effect today as a north-northwest swell builds down the island chain.

The high surf warning, due to expire at 6 p.m. Wednesday, covers the north and west shores of Kauai County, Oahu and Molokai, and the north shores of the island of Maui.

Weather officials expect surf of 10 to 15 feet building to 25 to 30 feet tonight through Wednesday along affected north shores. Surf of 8 to 12 feet building to 15 to 25 feet tonight through Wednesday is forecast for west shores.

Surf along exposed north and west shores will build through the day, then peak above warning levels this evening through Wednesday, according to the National Weather Service.

“Expect ocean water surging and sweeping across beaches, coastal benches, and lava flows creating the potential for impacts to coastal properties and infrastructure, including roadways,” the NWS said in a bulletin today. “Powerful longshore and rip currents will be present at most beaches. Large breaking waves and strong currents may impact harbor entrances and channels causing challenging boat handling.”