Update 5:30PM CDT…
Winter Weather Advisories for 2 to 5-inches of snow continue tonight for portions of central and southern Illinois and Indiana into southern Ohio (purple-shaded area on the highlighted map). With rain/thunderstorms south of the Ohio River, where the rain merges with the band of snow there exists a wintry mix of freezing rain, sleet and wet snow. Travel south out of Chicago will encounter slow hazardous conditions tonight into the early morning hours Monday.
A band of 2 to 5-inches of snow is expected across northern Missouri through Central portions of Illinois and Indiana this Sunday afternoon and overnight causing difficult travel conditions for those headed south out of Chicago. Note the Winter Weather Advisory for 2 to 5-inches of snow is outlined in purple on the highlighted map and actually extends out of Nebraska all the way east into Indiana.
Cold Canadian-source high pressure has invaded the Chicago area all the way south into the Ohio River Valley with temperatures expected to peak in the 30s area-wide today, dropping back into the 20s tonight. With this cold air in place and a center of low pressure tracking east out of Arkansas into Kentucky (see map below), a broad band of precipitation will spread north from the low pressure, producing rain in southernmost sections closest to the low pressure center and a swath of accumulating snow farther north. If you are anticipating travel south, be prepared for hazardous, slow, slick conditions in the Advisory areas.