A high-surf advisory has been issued by the National Weather Service for the north- and west-facing shores of Kaua'i and O'ahu and the north shores of Moloka'i and Maui through tomorrow afternoon.

Open ocean swells from a Pacific storm northwest of the Hawaiian Islands have reached these shores, the National Weather Service said.

The advisory is in effect until 6 p.m. tomorrow.

Surf along north-facing shores will be 16 feet to 20 feet through today, diminishing to 12 feet to 15 feet tomorrow. West-facing shores will see surf 6 feet to 12 feet.

The current northwest swell will be reinforced by an even larger northwest swell Thursday that will likely push surf above the 25-foot warning level for north-facing shores.

Eastern shores will see surf 2 feet to 4 feet, while surf along south shores will be 1 foot to 3 feet.