Generally speaking around the St. Louis metro I am expecting 2" to 3" of snow to fall. There will likely be a few spits of snow through late morning but I don't expect the accumulating snow to begin until mid-afternoon and it should end by 2am Tuesday. Snow showers will be possible Tuesday morning (rush hour +) but shouldn't add to the totals.
Southeast Missouri/Southern Illinois/Western Kentucky:
The forecast will be a little trickier for this area as there will likely be a mix of snow, sleet and freezing rain north to south across the area.
- Places like Cape Girardeau, Perryville, Sikeston, Carbondale, Marion (IL) and Harrisburg there could be 0.5" of snow to at the high end 1". Towards the end of the event, the snow is likely to change over to sleet or a little freezing rain.
- Places like Poplar Bluff, New Madrid, Paducah, Mayfield, Murray and south will mainly see light sleet/freezing rain. There could be a little snow mixed in for Poplar Bluff and Paducah but it should be no more than 0.25"
I think we are looking at anywhere from 1" to as much as 3" of snow. I think the 3" amounts will be northwest of Indianapolis.