'Isolated tornadoes'

So I'm driving around today in Dallas, and it's middle of March weather. Blustery, warm, windy, and bordering on hazardous. So we're supposed to get some massive amount of rain in the next couple of days. And the radio announcer says there will be some "and a couple of isolated tornados." What is an isolated tornado? Aren't all tornados isolated? And is this supposed to make me feel more comfortable? I'm sure that it doesn't make it easier on the person whose barn gets knocked over.