CHICAGO (CBS) — Planning to head to the beach to kick off the weekend? You’ll want to stay out of the water, because of large waves and dangerous currents.

The National Weather Service has issued a beach hazard statement through midnight Friday night for all Lake Michigan beaches in Cook County and northwest Indiana, due to waves of up to 6 feet high and strong rip currents and structural currents.

A small craft advisory also has been issued until 6 p.m. Friday, warning boaters of wind speeds up to 33 knots, which could prove hazardous. Inexperienced boaters and smaller boats should avoid going out on the lake in these conditions.

People visiting those beaches are being warned to stay out of the water on Friday.

According to the National Weather Service, conditions will be much calmer on Saturday.

Anyone planning to go to the beaches should check the Chicago Park District’s swim advisories before entering the water. The Park District posts swim conditions on its website, and also uses a three-color flag system at the beaches. Green flags mean swimming is allowed, yellow flags mean there is an advisory for weather conditions or high bacteria levels, and red flags mean swimming has been banned.

Swimming at Chicago beaches is only allowed when lifeguards are on duty, from 11 a.m. to 7 p.m. from Memorial Day weekend through Labor Day.