A high surf advisory remains in effect until 6 p.m. today for all north- and west facing shores of Kaua'i and Ni'ihau and the north-facing shores of O'ahu, Moloka'i and Maui.

Strong winds generated by a gale to the north of the islands have reinforced the large northwest swell that began rolling up on Hawai'i shores on Sunday, the National Weather Service said. The swell will continue to produce above normal surf mainly along the north-facing shores of most of the smaller Hawaiian Islands, forecasters said.

Surf heights of 14 to 18 feet are expected today along the north- and west-facing shores of Ni'ihau and Kaua'i today. Surf of 10 to 15 feet is expected along the north-facing shores of O'ahu, Moloka'i and Maui.

Elsewhere on O'ahu, look for surf of 6 to 10 feet along west-facing shores, 4 to 6 feet along east-facing shores and 2 to 4 feet along south-facing shores.

Outlook through Sunday, Oct. 19: The current north northwest swell will remain near the advisory threshold through today before slowly lowering tonight and tomorrow.

A much smaller northwest swell from 320 degrees is expected to fill in Thursday night, peak on Friday, then slowly lower into the weekend. Small background swells from the south will continue through the week, with a slightly larger swell from 190 degrees possibly filling in late Friday into Saturday. Short period east swells will continue throughout the week.