The Fujita Scale

Dr. Tetsuya Theodore Fujita, a pioneering researcher in the formation and development of severe weather, proposes a scale for judging the intensity of tornadoes by the damage left behind. His five-point scale covers minimal tornadoes (F1) through storms capable of inflicting incredible damage (F5), with damage surveyed after a storm to determine the physical effects and the estimated wind speed needed to cause those effects. The Fujita Scale is adopted almost worldwide, remaining in widespread use by severe weather researchers and government agencies until it is supplanted by the more refined Enhanced Fujita Scale in the 1990s.