I was within a mile of one of the tornadoes back in April of 2011. I could hear it very well (loud roar) and found paperwork in my yard from a house that was 30 miles away. Several homes were wiped off their fondation. Hopefully nothing like that day materializes today. I usually keep up with the weather but that day I was not, and had no clue what was going on. My first clue that something bad was near was the changing wind direction as the storm progressed.
Moral of the story, keep an eye on things today, surprises can pop up fast.