I'm off today, but I have to give you my take on our wintry mix situation for overnight tonight (Monday) into early Tuesday morning.
In the Nashville Metro area to Clarksville and Dickson precipitation will not begin until 10 p.m. to midnight.
It will start as sleet/snow/freezing rain mix and quickly become all snow after midnight, tapering off by sunrise. Snow sleet accumulations a dusting to 1/2" (some areas may be able to claim one inch).
East and northeast of Nashville from Lebanon to Cookeville, Lafayette, Carthage, Smithville, Livingston, Gainesboro, Monterey, and Crossville, the change from freezing rain/sleet/snow to all snow should take place by 1-2AM and possibly yield 1-2" of snow.
From points southeast of Murfreesboro southward the precip may begin 8-9PM but stay freezing rain/sleet until around 3AM when it will become a sleet/snow mix, ending as a little snow. A dusting at most possible there. However, ice accumulations could be one tenth of an inch.
All precip should end around sunrise or shortly after, but there could be slick roads for the morning rush hour commute.