Surf along northern shores will be 6 to 10 feet this morning, build to 12 to 16 feet by the afternoon and rise to 22 to 28 feet tonight. Northern shores of Ni'ihau, Kaua'i, O'ahu, Moloka'i and Maui are under a high surf warning from noon today through 4 p.m. tomorrow.

A high surf warning means that dangerous surf is expected along the affected shorelines.

A high surf advisory has also been issued for O'ahu's west shores through tomorrow. An advisory means waves along the affected area will be higher than normal.

On the Big Island, a high surf advisory is in effect for north and west shores tonight through tomorrow night.

Surf along west shores will be 4 to 7 feet through this morning, building to 8 to 12 feet by the afternoon and to 14 to 18 feet tonight, the National Weather Service said.

The remainder of the surf forecast calls for east shores to see surf 3 to 6 feet today and south shores to see surf 1 to 3 feet.

Surf heights are forecast heights of the face or front of waves. 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.

"This is the highest surf forecast of the 2006 season," said Bill Balfour, O'ahu Civil Defense administrator. "This is also a rather late season swell."

Officials urged ocean-goers and coastal residents to be aware of the high surf, and take necessary precautions. O'ahu Civil Defense also said:

i Drivers driving along the North Shore should exercise caution as roads can become blocked with sand and debris.

i Beachgoers should stay well away from the water and from spots overlooking the ocean, which could be suddenly inundated by a rogue wave.