The National Weather Service is warning people on beaches along Lake Michigan to stay out of the water because of dangerous swimming conditions.



A beach hazards alert is in effect until 9 p.m. today because of high waves and strong rip currents along the Illinois and Indiana shores. Temperatures are expected to get into the mid-70s today along the lakefront in Chicago.



"Rip currents are powerful channels of water flowing quickly away from shore which occur most often at low spots or breaks in sandbars," according to the weather service statement. "Rip currents can sweep you out from shore into deeper water."



Strong currents can also form along piers and breakwaters and sweep swimmers away from shore, according to the weather service.



Some area beaches are banning swimming today while others, including Wilmette, are restricting people to going into water that is waist deep or less, and requiring children in the water to be accompanied by an adult at all times. Some Chicago beaches also are closed because of poor water quality.

