Supercell: Mass of air generated by cold polar air meeting warm tropical air. The result of this union is the steady rotation of the body of air, caused by warm air rising and cooling.
Funnel: The most easily recognizable part of a tornado, it seems to decend from the base of the cloud. Some tornadoes have funnels that touch the ground while on rare occations, funnels do not decend.
Bernoulli's principle: This law states that as wind speed increases, atmospheric pressure decreases.
Tornado watch: This announcement signifies that a tornado is possible
Tornado warning: This announcement signifies that a tornado has been spotted and that you must get into a shelter immidiately.
Fujita-Pearson Scale: Scale by which tornado strength is measured. There are seven classes of strength, from zero to six.
Professor Fujita: Retired professor of the University of Chicago.
Dr. Pearson: Director of the National Severe Storm Forcast Center.
Cumulonimbus: Cloud type in which tornadoes occur. Shaped as a towering anvil.