A couple of very big car races will take place this Sunday. The first is the Indy 500, which starts early in the afternoon. It will be quite warm in Indianapolis Sunday with temperatures reaching the middle 80s. The warmth will cause thunderstorm clouds to boil upward during the afternoon, and there is a chance that one of those bad boys could drift over the racetrack.

Later in the day, the Coca Cola 600 will be held at the Charlotte Motor Speedway. There is a chance for a thunderstorm during that race too, but again it will be very much a hit-or-miss sort of thing.

Individual thunderstorms have well defined edges, and so do the rain patterns they produce. Why, just the other day my son (works at a local golf course) reported heavy rain on 17th fairway and 18th tee, but not a drop of rain fell at the clubhouse (less than 500 yards away).

Story by AccuWeather.com Senior Meteorologist John Kocet.