1.   Doppler radar is able to detect twisting winds in a thunderstorm, a sign that a tornado might be forming.

2.   If the wind speed increases dramatically as you move higher and the wind changes direction, chances are a tornado is forming, says Marquis.

3.   Isolated tornadoes will form.

4.   Moments later, tornadoes formed in that area.

5.   Most important, researchers witnessed several events within severe storms that seemed to predict when tornadoes would form.

6.   Tornadoes form when warm, moist air fills the lower atmosphere and the temperature of the air above drops rapidly.

7.   Tornadic waterspouts, which occur when tornadoes form over land and move over water are much more dangerous.

8.   Tornadoes form most frequently in the Midwest when large masses of warm and cold air come together and move rapidly across the open plains.

9.   Tornadoes form when rising currents of air tilt these horizontal rolls into spinning, vertical columns of air.

10.   Tornadoes historically form on the outer edges of hurricanes, especially powerful ones.