The National Weather Service has issued a Winter Weather Advisory until 10pm for Winnebago, Boone, McHenry, Ogle, Lee and DeKalb counties due to blowing and drifting snow.
West winds have been fairly strong this afternoon and evening causing blowing snow over open roadways. North/south roads are the main concern, but there will be some drifting over east/west roads too. Winds will remain gusty through midnight and will gradually taper off towards sunrise Thursday. Be careful on the roads, especially if you're in an area that tends to get a lot of blowing and drifting snow. Roads will be slick and drifts hard to see now that it's dark outside.
A Wind Chill Advisory will go into effect at 9pm for Northern Illinois and Southern Wisconsin due to wind chills dropping below -20° by Thursday morning. The center of high pressure moves overhead by mid-morning Thursday and this will give some improvement in the wind chill throughout the day.