Wow, looking at it more closely, it drops 8 inches in 3 hours from the 18 to 21 hour. Almost 3" an hour rates. That would definitely overcome the ground temps quickly!
Anyone else notice that glob of pink that starts in Arkansas and travels all the way up to Pennsylvania? Looked like a long track super-cell of snowmaggeden under that thing.
MRX is going to say 1-3 for the valley with locally heavier amounts and issue a WWA and call it a day. I'd be surprised if they issue anything more than that today. They might even wait and let the night crew issue it.