Strong to severe storms will arrive very late tonight from Middle Tennessee into the Plateau and weaken as it gets into the Valley. FYI. This means thunderstorms are possible for Knoxville and the Valley, for example, but probably not "strong to severe" early Sunday morning. Hope this helps.
P.S. BEFORE strong to severe storms strike, be sure you and your family have a way to get notified. Download the Captain Accurate Weather App. It's FREE at the App Store and Google Play. You'll get lightning alerts, and every NWS Warning, Watch, Advisory and Statement that you can imagine, straight to your smartphone or iPad, without delay......plus, 3 radar extras that are exclusive to Baron Services: Severe "Storms in Area," "Dangerous Storm Approaching" and "Twisting Storm Approaching."