Tornadoes

Tornadoes: Backgrounder

Emergency information

The best protection during a tornado is in an interior room on the lowest level of a building, preferably a safe room.
Tornadoes strike with incredible velocity. Wind speeds may approach 300 miles per hour. These winds can uproot trees and structures and turn harmless objects into deadly missiles, all in a matter of seconds. Mobile homes are particularly vulnerable to tornadoes.
Injury or deaths related to tornadoes most often occur when buildings collapse, people are hit by flying objects or are caught trying to escape
Tornadoes are most destructive when they touch ground. Normally a tornado will stay on the ground for no more than 20 minutes; however, one tornado can touch ground several times in different areas.

Danger zones

Tornadoes can occur in any state but are more frequent in the Midwest, Southeast and Southwest. The states of Alabama, Arkansas, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Mississippi, Missouri, Nebraska, Oklahoma, South Dakota, and Texas are at greatest risk.

What is a tornado?

A tornado is a violent windstorm characterized by a twisting, funnel-shaped cloud. It is spawned by a thunderstorm (or sometimes as a result of a hurricane) and produced when cool air overrides a layer of warm air, forcing the warm air to rise rapidly. The damage from a tornado is a result of the high wind velocity and wind-blown debris. Tornado season is generally March through August, although tornadoes can occur at any time of year. They tend to occur in the afternoons and evenings: over 80 percent of all tornadoes strike between noon and midnight.

Help your community get ready

The media can raise awareness about tornadoes by providing important information to the community. Here are some suggestions:

Publish a special section in your local newspaper with emergency information about tornadoes. Localize the information by printing the phone numbers of local emergency services offices, the American Red Cross, and hospitals.
Periodically inform your community of local public warning systems.
Sponsor a "Helping Your Neighbor" program at your local schools to encourage children to think of those persons who require special assistance such as elderly people, infants, or people with disabilities.
Conduct a series on how to protect yourself during a tornado in case you are at home, in a car, at the office, or outside.
Interview local officials about what people living in mobile home parks should do if a tornado warning is issued.

Did you know?

Tornadoes can be nearly invisible, marked only by swirling debris at the base of the funnel. Some are composed almost entirely of windblown dust and still others are composed of several mini-funnels.
On average, the United States experiences 100,000 thunderstorms each year. Approximately 1,000 tornadoes develop from these storms.
Although tornadoes do occur throughout the world, the United States experiences the most intense and devastating tornadoes.
Tornadoes produce the most violent winds on earth. Tornado winds can approach speeds as high as 300 miles per hour, travel distances over 100 miles and reach heights over 60,000 feet above ground.
In November 1988, 121 tornadoes struck 15 south central states, resulting in 14 lives lost and damages reaching $108 million.
According to the National Weather Service, about 42 people are killed because of tornadoes each year.

Fujita - Pearson Tornado Scale

F-0: 40-72 mph, chimney damage, tree branches broken
F-1: 73-112 mph, mobile homes pushed off foundation or overturned
F-2: 113-157 mph, considerable damage, mobile homes demolished, trees uprooted
F-3: 158-205 mph, roofs and walls torn down, trains overturned, cars thrown
F-4: 207-260 mph, well-constructed walls leveled
F-5: 261-318 mph, homes lifted off foundation and carried considerable distances, autos thrown as far as 100 meters