I remember when I was a teenager (30+ years ago)... if we started picking up TV signals from Joplin, MO (180 miles away) in the afternoon during spring, that meant more than likely we were getting ready to have tornadic weather. Inevitably, the sirens would sound.
I'm still not sure what method of propagation was allowing that signal to travel that far... the frontal boundary alone? Or perhaps a large, nearby hail core in a supercell storm?