Tornadoes Notes

Learn tornado safety! Know the difference between a watch and a warning and understand the Fujita scale.

Tornado WATCH vs. Tornado WARNING Tornado WatchTornadoes are possible in and near the watch area. Review and discuss your emergency plans, and check supplies and your safe room. Be ready to act quickly if a warning is issued or you suspect a tornado is approaching. Acting early helps to save lives!Tornado WarningA tornado has been sighted or indicated by weather radar. Tornado warnings indicate imminent danger to life and property. Go immediately under ground to a basement, storm cellar or an interior room (closet, hallway or bathroom). Different Sizes and Types Weaker Tornadoes 88 % of all tornadoes Less than 5% of tornado caused deaths Stay on the ground for 1-10+ minutes Winds less than 110 mphStrong Tornadoes 11 % of all tornadoes Nearly 30% of all tornado caused deaths Stay on the ground for 20+ minutes Winds 110-205 mphViolent Tornadoes Less than 1% of all tornadoes 70% of all tornado caused deaths Stay on the ground for over an hour Winds greater than 205 mph Fujita Scale F-0 40-72 mph Chimney damage; tree branches broken demolished, trees uprootedF-1 73-112 mph Mobile homes pushed off foundation or overturnedF-2 113-157 mph Considerable damage, mobile homes F-3 158-205 mph Roofs and walls torn down, trains overturned, cars thrown aboutF-4 207-260 mph Well-Constructed houses levelledF-5 261-318 mph Homes lifted off foundations and carried considerable distances; automobiles thrown as far as 100m Where and When do Tornadoes Occur? Although tornadoes occur in some form on all continents, it is the U.S.A. where they most frequently cause disaster.Tornadoes usually form during cloudy, stormy weather during the 'tornado season' in early Spring.The number of funnels observed each year can vary greatly in any given region.Texas and the southern states of the U.S.A. are visited by hundreds of tornadoes a year.Because they are so common in this area, the mid-western and south central U.S.A. has been nicknamed 'tornado alley'.