The National Weather Service has extended a high surf advisory for the south-facing shores of all Hawaiian isles to 6 p.m. today.

Forecasters said the current, long-period, south swell will maintain advisory-level surf into the afternoon. Surf of 8 to 12 feet is expected along south shores this morning before declining to 7 to 10 feet this afternoon.

Officials warn of strong, breaking waves and strong currents, which will make swimming dangerous.

“Heed all advice from ocean safety officials,” the advisory said. “When in doubt, don’t go out.”

Surf along east-facing shores, meanwhile, is expected to remain choppy and slightly elevated today, at 4 to 6 feet, before declining to 3 to 5 feet Wednesday.

Surf along west-facing shores is expected to decline from 5 to 7 feet this morning to 3 to 5 feet Wednesday.

Surf along north-facing shores will see a tiny bump due to a combination of swells that will boost it from 0 to 2 feet today to 2 to 4 feet Wednesday.

Forecasters expect the south swell to decline below advisory-level surf by tonight.