A high surf warning remains in effect for north- and west-facing shores from Niihau to the Big Island, while a high surf advisory has been posted for west-facing shores on Lanai.

Surf of 20 to 30 feet is expected today along north-facing shores, the National Weather Service said. It is expected to diminish to 18 to 23 feet on Friday.

Surf along west-facing shores of the smaller islands is expected to reach 15 to 22 feet today, lowering to 10 to 15 feet on Friday.

Surf along the west-facing shores of the Big Island is expected to reach 10 to 15 feet today through Friday morning before lowering to 6 to 10 feet Friday afternoon.

A large storm south of the eastern Aleutian Islands several days ago has generated a large northwest swell, the Weather Service said.

Surf in Hawaii peaked overnight, but the swell arriving on Hawaii shores was reinforced by a second storm-generated swell which will continue to produce high surf into the weekend, forecasters said.

The high surf warning will remain in effect until 6 a.m. Friday