Figure 5.13

Tornado intensity and frequency. (A) The enhanced Fujita scale (EF scale) uses six tornado strength categories. (B) Eighty percent of tornadoes are EF0 to EF1. Only 1% of all tornadoes in the United States are EF4 and EF5; however, those EF4 and EF5 tornadoes cause about two-thirds of tornado-related deaths.