NWS CR >> WFO Louisville >> Preparedness >> Tornadoes: Nature's Most
Violent Storms
Tornado Classifications
| Tornadoes are classified by the National Weather
Service three different ways:
Weak Tornadoes - Account for 69 percent of all tornadoes
and are defined as a tornado with winds under 110 mph. Weak
tornadoes last an average of 5 to 10 minutes and account for
approximately 3 percent of all tornado deaths.
Strong Tornadoes - Account for 29 percent of all tornadoes
and approximately 27 percent of all tornado deaths. Wind speeds
range from 110 to 205 mph, and these tornadoes may last 20 minutes
or longer.
Violent Tornadoes - Account for only 2 percent of all
tornadoes but result in 70 percent of all tornado deaths. Wind
speeds exceed 205 mph, and lifetimes can exceed one hour. |
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'Tornadoes: Nature's Most Violent Storms' was developed by the
National Oceanic and Atmospheric Administration (NOAA)/National Weather
Service (NWS) in cooperation with the American Red Cross and the Federal
Emergency Management Agency (FEMA). It is designed to assist in
heightening public awareness and understanding the dangers associated with
tornadoes. The package provides an introduction to tornadoes and their
impact, discusses tornado development and occurrence, and describes safety
information for homes, schools, places of work, and outdoors. In addition,
basic environmental clues are presented.
Individual use of the pictures within these presentation must have prior
approval from the credited source. |
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