Surf on north shores is down from Wednesday’s 25- to 35-foot wave faces, but is still big enough to prompt a high surf advisory for north and west shores of Kauai County, Oahu and Molokai and for north shores of Maui as what’s left of the current swell is reinforced by a new northwest swell arriving later Thursday.

The advisory is in effect until 6 p.m. Friday.

Surf is expected to be 10 to 15 feet Thursday evening along north shores, increasing to 14 to 18 feet Thursday night and Friday. West shores could see 8- to 12-foot wave faces through Friday.

Professional surfers thrilled crowds on the second day of the REEF Hawaiian Pro Thursday at Alii Beach Park in Haleiwa.

Organizers described the waves as "decreased, but still solid surf," with light wind conditions.

Hawaii surfer John John Florence, last year’s Van’s Triple Crown winner, withdrew from the competition because of an injury suffered Wednesday, contest organizers said Thursday. The withdrawal will affect his chances for a fourth Triple Crown title. Hawaii surfer Keanu Asing will replace Florence in Round 3.

While the waves are ideal for experience and professional surfers, National Weather Service forecasters warn that breaking waves, shore break and strong currents could make swimming dangerous.

"Always heed lifeguard advice and know your limits. When in doubt, do not go out," forecasters said in an advisory.