Easy way to tell: barometric pressure and dropping dew-point - this from my wx station recently:
Water Vapor Image
Still expecting the 8:36 PM switch, so 2 hours approx.
Rain should ease up for a bit and then begin again heavily and the harder it falls the sooner we switch over as cold air is drawn down into the lower levels more rapidly. Thunder-snow not out of the question honestly.
Snowing in Boone and Jefferson (around 3500') and the line between rain and snow should move eastward rather quickly as banding precip sets up. If you look at radar now and say it's all gone, just wait.