Definition of the Fujita Tornado Scale – Developed by Professor Theodore Fujita of the University of Chicago to classify tornadoes according to wind speed and damage.

(F0)          Gale Tornado (40 – 72 m.p.h.) - Light damage:  Some damage to chimneys; break branches off trees; push over shallow-rooted trees; damage sign boards

(F1)          Moderate Tornado (73 – 112 m.p.h.) - Moderate damage:  The lower limit (73 m.p.h.) is the beginning of hurricane wind speed; peel surface off roofs; mobile homes pushed off foundations or overturned; moving auto pushed off road

(F2)          Significant Tornado (112 – 157 m.p.h.) - Considerable damage:  Roofs torn off frame houses; mobile home demolished; boxcars pushed over; large trees snapped or uprooted; heavy cars lifted off ground and thrown

(F3)          Severe Tornado (158 – 206 m.p.h.) - Severe damage:  Roof and some walls torn off well-constructed houses; trains overturned; most trees in forests uprooted; heavy cars lifted off ground and thrown

(F4)          Devastating Tornado (207 – 260 m.p.h.) - Devastating damage:  Well-constructed houses leveled; structures blown off weak foundations; cars and other large objects thrown about

(F5)          Incredible Tornado (261 – 318 m.p.h.) – Incredible damage:  Strong frame houses are lifted off foundations and carried a considerable distance to disintegrate; automobile-sized missiles fly through air in excess of 100 meters; trees debarked

(F6+)        Inconceivable Tornado (319 – 379 m.p.h.)  The maximum wind speed of tornadoes is not expected to reach the F6 wind speeds.

·        Tornadoes can be classified into one of three types:

Weak Tornadoes (F0/F1)         account for 74 percent of all tornadoes cause less than 5 percent of tornado deaths; lifetime usually 1-10+ minutes; wind speeds are less than 113 m.p.h.

Strong Tornadoes (F2/F3)         account for 25 percent of all tornadoes cause nearly 30 percent of all tornado deaths; may last 20 minutes or longer; wind speeds are 113 m.p.h. to 206 m.p.h.

Violent Tornadoes (F4/F5)         account for less than 2 percent of all tornadoes cause 67 percent of all tornado deaths nationwide; may last for one hour or more; wind speeds are greater than 206 m.p.h.

·        Since 1950, North Carolina has averaged 14 tornadoes and two tornado-related fatalities each year.  The year 1998 was a record tornado year in North Carolina, with 66 confirmed tornadoes through the end of November.  The previous record year was 1996, when 51 tornadoes hit the state.  In 2000, North Carolina experienced 23 tornadoes that caused one injury.

·        In North Carolina, F1 tornadoes account for 74 percent of all tornadoes.  Only 1.6 percent of this state’s tornadoes had a F4 classification; tornadoes classified as F4 cause 44.6 percent of the injuries and 45.8 percent of the fatalities in North Carolina.