Southwest winds gusting as high as 40 mph at Midway airport Monday afternoon, propelled 80-degree warmth across the entire metro area. Even often lake-chilled locations such as Northerly Island and Waukegan had temperatures reach the 80-degree mark. Forecasts suggest several frontal boundaries will cross the region this week, resulting in frequent wind shifts. The southwest winds of Monday are to turn north on Tuesday, resulting in 24-hour temperature changes of 20 degrees or more. Afternoon readings are expected to reach seasonable levels inland, but areas nearer the lake are to hold in the 50s. Southwest winds are due to resume midweek, bringing another influx of mild air Thursday, before stout north to northeast winds lock in on Friday. With the open waters of lake Michigan hovering just above 40 degrees, areas along lake Michigan will be most susceptible to these temperature swings.