A high surf advisory has been issued for the north- and west-facing shores of the isle chain from Niihau to Maui, in effect through 6 p.m. today, weather officials said.

Although the current northwest swell is on the decline, surf is expected to increase again tonight as a new, larger northwest swell begins to build, the National Weather Service said.

Surf today is expected to reach heights of 12 to 16 feet along north- and west-facing shores of Niihau and Kauai, and north-facing shores of Oahu, Molokai and Maui; and heights of 8 to 12 feet along west-facing shores of Oahu and Molokai.

Surf is expected to build again tonight as the new swell arrives, bringing warning-level surf once again along the north- and west-facing shores of smaller isles, and likely reaching advisory levels over portions of the Big Island.

Strong, breaking waves, and rip currents are expected, making swimming difficult and dangerous. Beachgoers, swimmers, and surfers should exercise caution and heed all advice given by Ocean Safety officials and exercise.

Finals day of the World Surf League’s Billabong Pipe Masters, on Oahu’s North Shore, meanwhile, was called on this morning due to the pumping, 6-to-8-foot wave conditions. A World Champ is expected to be crowned today.