A combination of dangerous winter weather will be in effect for portions of the Chicago area along and just south of Interstate-80 north to the Illinois-Wisconsin state line as a strong low pressure system moves through from west to east.
Wind chills -15 to -25 degrees have prompted a Wind Chill Advisory over this area until 9AM CST this Sunday morning.
From this Sunday evening overnight into Monday morning heavy snow and blowing snow is expected over this same area. A Winter Storm Warning (pink-shaded on headlined map) for 6 to 8-inches of snow and blowing snow is in effect in Illinois counties bordering Wisconsin. A Winter Weather Advisory (purple-shaded area) for generally 3 to 6-inches of snow and blowing snow is forecast with a gradation of heaviest snow north to least far southern portions of the Winter Weather Advisory.
Heavy snow should diminish Monday morning, but hazardous travel and outdoor conditions should continue with periods of first freezing drizzle and then snow showers along with blowing snow, as colder air follows into the area behind the departing low pressure.
Areas farther south of the Warning/Advisory will experience a light wintry mix of wind, snow, rain, drizzle and eventually falling temperatures.