A high surf warning remains in effect for north and west shores of Niihau, Kauai, Oahu and Molokai, and for north-facing shores of Maui until 6 p.m. today.

The National Weather Service said surf associated with a large northwest swell that peaked Sunday will hold through today and rise to warning levels for north and west shores on the smaller islands, then drop to advisory levels tonight into Tuesday.

Surf is expected to reach 20 to 30 feet along north and west facing of affected isles, and 12 to 20 feet along the west shores of Oahu and Molokai.

Expect ocean water sweeping across portions of beaches, very strong breaking waves, and strong longshore and rip currents. The advisory advises “inexperienced persons” to remain off beaches and beachfront areas.

“Surf events of this caliber also have the ability to cause significant impacts to shorelines,” said the advisory, especially those already susceptible to erosion.”

The west-facing shores of Hawaii island, meanwhile, will experience surf between 5 to 8 feet today while the island’s north-facing shores should see surf between 10 to 15 feet, according to the high surf advisory posted for the island this morning.