The National Weather Service has extended a high surf advisory for the north shores of most Hawaiian islands to Friday morning.

Surf of 12 to 16 feet is expected today on the north shores of Niihau, Kauai, Oahu, Molokai and Maui due to a short- to medium-period north swell.

The swell should peak today, then gradually subside tonight and Friday.

Officials advise the public of strong, breaking waves and strong rip currents, making swimming difficult and dangerous.

Beachgoers, swimmers and surfers should exercise caution and heed all advice given by ocean safety officials.

Surf along west shores is expected to remain at 6 to 8 feet today to Friday.

A series of moderate, long-period south swells will keep surf along south shores elevated, at 4 to 6 feet today and up to 6 to 7 feet Friday afternoon.

Surf along east shores is expected to get a boost from north swell wrap to 3 to 5 feet today through Friday.

A small craft advisory for Alenuihaha Channel and Hawaii island windward waters also remains in effect until 6 p.m. today.