UPDATE 11:59AM: The Winter Storm Watch for southern Wisconsin has been upgraded to a warning. A Winter Storm Warning is in effect for Walworth, Racine and Kenosha counties from 6AM Thursday through Midnight. Winter Storm Watch for Lake and McHenry Counties in Illinois Thursday morning through Thursday evening.
9:20AM: The National Weather Service has issued a Winter Storm Watch for Lake and McHenry counties in northern Illinois. This watch does not include the city of Chicago.
A wintery mix of freezing rain, sleet and snow is expected to develop across the metro area early Thursday morning. Significant ice and snow accumulation is possible over the northern suburbs tomorrow. South of the Winter Storm Watch area, the ice and snow accumulation is expected to be limited as temperatures rise above 32 degrees by late Thursday morning.
This storm will have to be monitored closely over the next 24 hours as it evolves. Any subtle shift in track or temperature could lead to significant snow or icing across a larger portion of northern Illinois.
A Winter Storm Watch has also been posted for much of southeastern Wisconsin including Walworth, Racine and Kenosha counties.