A new northwest swell has triggered a high-surf warning for the north- and west-facing shores of Niihau, Kauai, Oahu and Molokai and north-facing shores of Maui through this afternoon, with a second swell right on its heels, according to the National Weather Service.

Forecasters said to expect surf as high as 25 to 35 feet today on north shores and 22 to 26 feet on west shores. Waves on south- and east-facing shores will range from only 1 to 4 feet, the service said.

As the swell moves down the island chain, a surf advisory may be issued for west-facing shores of Hawaii island for this afternoon.

A smaller northwest swell will continue to bring large surf along exposed north- and west-facing shores Sunday, according to the Weather Service. The waves will subside Monday as the two swells pass, but another one could reach the islands and produce advisory-level surf during the middle of next week.

Officials warn of ocean water occasionally sweeping across portions of beaches, significant shorebreak and dangerous currents.

A small-craft advisory remains in effect for all Hawaii waters through 6 p.m. today.

Meanwhile, showers will increase over Hawaii island and East Maui today, spreading across the rest of the island chain by Sunday afternoon, forecasters said. The moisture will linger across the state Monday, with a decrease in showers likely Tuesday.