A high surf advisory will remain in effect until 6 p.m. Thursday for the north- and west-facing shores of Niihau, Kauai, Oahu, Molokai and Maui.

Surf today is expected to be 15 to 20 feet along the north- and west-facing shores of Niihau and Kauai, the National Weather Service said.

Surf of 14 to 18 feet is expected along the north-facing shores of Oahu, Molokai and Maui, forecasters said.

West-facing shores on Oahu can expect surf of 10 to 14 feet today.

The surf is expected to diminish tonight and into tomorrow.

Meanwhile, surf along east-facing shores on Oahu will remain 2 to 3 feet through today, while surf along Oahu's south facing shores will be 3 feet or less.

Outlook through Saturday, Jan. 17: The ongoing northwest swell will begin subsiding tonight. A very large swell arriving Wednesday will produce surf above the warning threshold along north- and west-facing shores, with another very large swell reinforcing it on Friday.