The first of three swells will push surf on north- and west-facing shores of Oahu, Molokai, Kauai, Niihau, and north shores of Maui to advisory levels today.
A high surf advisory is posted from 6 a.m. to 6 p.m. today.
Forecasters say surf will peak in the 12- to 16-foot range today on north shores and and west shores will see waves with 8- to 12-foot faces.
A significantly larger swell will arrive Thursday and bring surf well in excess of high surf warning levels through Friday.
A third swell is expected to arrive this weekend with more warning-level surf.
Organizers of the Quicksilver in Memory of Eddie Aikau surf contest, held only when waves are consistently 20-feet or higher by Hawaiian-style measurements, are watching the swell forecasts to see if they will be big enough for the contest to be held.
Forecasters say beachgoers today should expect strong, breaking waves and currents that will make swimming difficult and dangerous.
Beachgoers., swimmers and surfers should heed all advice given by ocean safety officials and exercise caution.