The warning is in effect for the northern shores of Kaua'i, O'ahu, Moloka'i, Maui and the Big Island, and the western shores of Kaua'i, O'ahu, and the Big Island.

Surf along north facing shores will be as high as 30 feet on outer reefs today, the National Weather Service said. Northerly winds will likely make stormy surf conditions.

Surf along west shores will be 12 to 20 feet today. Northerly winds may produce stormy surf conditions.

Surf along east shores will remain 3 to 6 feet while surf along south shores will be 1 to 3 feet.

Surf will likely drop below the 25 foot warning threshold by tomorrow but remain above the 15 foot advisory level until Thursday. Another northwest swell will produce surf just below warning levels early Friday.

Surf heights are forecast heights of the face or front of waves. The surf forecast is based on the significant wave height in the zone of maximum refraction. Some waves may be more than twice as high as the significant wave height. Expect to encounter rip currents in or near any surf zone.