As summer boating season on Lake Michigan winds down, the National Weather Service warned boaters of dangerous conditions extending into the early afternoon.

       The weather service put out a special marine warning Wednesday morning of high waves and possible waterspouts. The warning was in effect until 12:15, though thunderstorms over the southern half of the Lake are forecast to continue throughout the day.

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       Boaters in Chicago’s northern suburbs, from Winthrop Harbor to Winnetka, were particularly urged to stay off the water, facing winds up to 34 knots that could capsize boats, according to the weather service.