From the National Weather Service:

WINTER STORM WARNING FOR THURSDAY MORNING THROUGH THURSDAY EVENING

LIGHT SNOW WILL SPREAD EAST ACROSS THE MISSISSIPPI RIVER INTO THE SOUTHERN TIP OF ILLINOIS AND SOUTHWEST KENTUCKY SHORTLY AFTER SUNRISE THURSDAY. THE SNOW SHOULD INCREASE DURING THE MORNING WITH A PERIOD OF MODERATE TO HEAVY SNOW LIKELY BY EARLY AFTERNOON. THE SNOWS WILL TAPER OFF TO FLURRIES BY EARLY THURSDAY EVENING. A TOTAL SNOW ACCUMULATION OF 4 INCHES OR MORE WILL BE POSSIBLE...WITH SOME ISOLATED AREAS RECEIVING UP TO 8 INCHES.