Surfers should enjoy advisory-sized waves until Saturday night as a reinforcement swell arrives on south shores of all islands. But inexperienced swimmers and surfers  should stay out of the water, the National Weather Service said.

Surf along south-facing shores will be 6 to 8 feet with higher sets, forecasters say. 

The swell is expected to decline Thursday. But another, slightly larger south swell will  arrive peaking Friday, forecasters say. The high surf advisory is in effect until 6 p.m. Saturday.

Increasing trade winds may also push surf above the advisory level for east shores  by the end of the week, forecasters say.

The pair of swells are the result of two powerful storms near New Zealand last week.

Forecasters say the large breaking waves will produce dangerous rip currents.