I could be totally off base here, but my gut tells me the dynamics at play are going to keep TN all snow for this event. If you look at the 850 temps on the NAM, you can see them sneak above 0 south of I-40, then as the levels saturate they quickly cool below freezing starting in Northern MS and AL and spreading northward. The wetbulbs are well below freezing. I don't see enough warming to actually cause a changeover. Might see lowered ratios and sloppy wet snow though.