UPDATE: 6 p.m.

The National Weather Service expanded its high surf advisory to include the north shores of Maui and Molokai.

Surf is expected to build overnight and peak Thursday before diminshing through Friday.

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A high surf advisory has been issued for the north facing shores of Kauai County and Oahu, effective until 6 p.m. Thursday.

The National Weather Service says a north swell will generate advisory-level surf along these shores through Thursday afternoon. Surf is expected to build up to 12 to 16 feet this afternoon, then increase to 14 to 18 feet Thursday before lowering later that night through Saturday.

Officials warn of shore break, strong, breaking waves and strong rip currents, making swimming difficult and dangerous.

Beachgoers, swimmers, and surfers should exercise caution and heed all advice given by ocean safety officials.

Surf on west facing shores, meanwhile, is set to increase from 5 to 7 feet this morning to 14 to 18 feet on Thursday.

Surf on south facing shores is expected to increase from 3 to 5 feet this morning to 5 to 7 feet Thursday morning due to a series of moderate, long-period south swells, and surf for east facing shores is expected to increase from 2 to 4 feet this morning to 4 to 6 feet Thursday from north swell wrap.

A box jellyfish advisory has also been issued for Waikiki after lifeguards observed them along the shoreline this morning. Warning signs have been posted.

Box jellyfish can cause severe stings, officials said, and the public should use caution entering water in the Waikiki area.

The public is advised to visit any lifeguard tower for the most up-to-date information.