The tornadoes are classified on the basis of the damage they produce on a scale ranging from 0 to 5, the scale Enhanced Fuijta

EF0 light damage. Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over. With winds from 65 to 85 mph

EF1 Damage moderate. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken. With winds from 86 to 110 mph

EF2 Considerable damage. Roofs torn off well-constructed houses; foundations of frame homes shifted; mobile homes completely destroyed; large trees snapped or uprooted; light-object missiles generated; cars lifted off ground. With winds from 111 to 135 mph

EF3 Severe damage. Entire stories of well-constructed houses destroyed; severe damage to large buildings such as shopping malls; trains overturned; trees debarked; heavy cars lifted off the ground and thrown; structures with weak foundations blown away some distance. With winds from 136 to 165 mph

EF4 Devastating damage. Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated. With winds from 166 to 200 mph

EF5 Incredible damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (109 yd); steel reinforced concrete structure badly damaged; high-rise buildings have significant structural deformation; incredible phenomena will occur. With winds over 200 mph

One of the most powerful EF5 in the U.S. with winds over 310 mph as in the case of the famous and devastating EF5 of May 3, 1999 that devastated Oklahoma and Kansas. That day on the plains of the United States have seen 74 tornadoes in 21 hours, which caused 46 dead, 800 injured and about 8000 homes damaged or destroyed.

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