Enhanced Fujita Scale EF0 EF1 EF2 EF3 EF4 EF5
see also Tornado Early Warning System

The Enhanced Fujita Scale, or EF Scale, is the scale for rating the strength of tornadoes in the United States estimated via the damage they cause. Implemented in place of the Fujita scale introduced in 1971, it began operational use on February 1, 2007. The scale has the same basic design as the original Fujita scale, six categories from zero to five representing increasing degrees of damage. It was revised to reflect better examinations of tornado damage surveys, so as to align wind speeds more closely with associated storm damage. Better standardizing and elucidating what was previously subjective and ambiguous, it also adds more types of structures as well as vegetation, expands degrees of damage, and better accounts for variables such as differences in construction quality.

Category EF0	Wind speed	65–85 mph	105–137 km/h
	Potential damage	EF0 damage example Light damage. Peels surface off some roofs; some damage to gutters or siding; branches broken off trees; shallow-rooted trees pushed over.
Category EF1	Wind speed	86–110 mph	138–178 km/h
	Potential damage	EF1 damage example Moderate damage. Roofs severely stripped; mobile homes overturned or badly damaged; loss of exterior doors; windows and other glass broken.
Category EF2	Wind speed	111–135 mph	179–218 km/h
	Potential damage	EF2 damage example 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.
Category EF3	Wind speed	136–165 mph	219–266 km/h
	Potential damage	EF3 damage example 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.
Category EF4	Wind speed	166–200 mph	267–322 km/h
	Potential damage	EF4 damage example Devastating damage. Well-constructed houses and whole frame houses completely leveled; cars thrown and small missiles generated.
Category EF5	Wind speed	>200 mph	>322 km/h
	Potential damage	EF5 damage example

The new scale was publicly unveiled by the National Weather Service at a conference of the American Meteorological Society in Atlanta on February 2, 2006. It was developed from 2000-2004 by the Fujita Scale Enhancement Project of the Wind Science and Engineering Research Center at Texas Tech University which brought together dozens of expert meteorologists and civil engineers in addition to its own resources.

As with the Fujita scale, the Enhanced Fujita Scale remains a proxy for actual wind speeds, and the wind speeds associated with the damage listed have not undergone rigorous scientific analysis (e.g. involving realistic physical or numerical modeling) owing to excessive cost. The wind speeds were attained as best guesses through a process of expert elicitation based on various engineering studies since the 1970s as well as from field experience of meteorologists and engineers. In addition to damage to structures and vegetation, radar data, photogrammetry, and ground swirl patterns may be utilized when available.

The scale was used for the first time a year after its public announcement when central Florida was struck by multiple tornadoes, the strongest of which were rated at EF-3 on the new scale.

The six categories for the EF Scale are listed below, in order of increasing intensity. Although the wind speeds and photographic damage examples are updated, the damage descriptions given are legacy descriptions which more or less remain accurate, however, for the EF scale, one must consult the respective damage indicator and associated degrees of damage.