Lake-effect snow, a relatively rare occurrence in Chicago, is providing the city with its biggest snow event of the season to date. Lake-effect snow develops when sufficiently cold air blows across the relatively warm waters of the Great Lakes, but this usually happens when winds are from the northwest. Lake Michigan’s lake-effect snows therefore usually fall in northwestern Indiana and western Lower Michigan. In the present situation however, northeast winds are directing snow across the Chicago area, with snow arriving […]