The Enhanced Fujita scale, an updated version of the original Fujita scale that was developed by Ted Fujita with Allen Pearson, assigns a numerical rating from EF0 to EF5 to rate the damage intensity of tornadoes. EF0 and EF1 tornadoes are considered "weak" tornadoes, EF2 and EF3 are classified as "strong" tornadoes, with winds of at least major hurricane force, where EF4 and EF5 are categorized as "violent" tornadoes, with winds corresponding to category 5 hurricane winds and rising to match or exceed the strongest tropical cyclones on record. The EF scale is based on tornado damage (primarily to buildings), which makes it difficult to rate tornadoes that strike in sparsely populated areas, where few man-made structures are found. The Enhanced Fujita scale went into effect on February 1, 2007.
|EF number||Wind speed||Comparable hurricane winds||Damage|
|0||65–85 mph (105–137 km/h)||Severe tropical storm – Category 1||Light damage. Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over.|
|1||86–110 (138–178 km/h)||Category 1–2||Moderate damage. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken.|
|2||111–135 (179–218 km/h)||Category 3||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.|
|3||136–165 (219–266 km/h)||Category 4–5||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.|
|4||166–200 (267–322 km/h)||Strong category 5||Devastating damage. Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated.|
|5||>200 (>322 km/h)||Hurricane Patricia||Explosive damage. Strong frame houses leveled off foundations and swept away; automobile-sized missiles fly through the air in excess of 100 m (300 ft); steel reinforced concrete structures badly damaged; high-rise buildings have significant structural deformation; incredible phenomena will occur.|