tornado,â which are basically used by tornado spotters to describe a tornadoâs shape and appearance. This does not by any means, however, say anything certain about a tornadoâs strength! Wedge tornadoes simply appear as wide as they are tall. Rope tornadoes are very narrow and often snakelike in appearance.
National Oceanic and Atmospheric Administration/Department of Commerce
A Few More Tornado Facts
Nearly 60 percent of tornadoes occur between noon and sunset. This is the time when the sun most heats the atmosphere, creating unstable conditions. The jet stream also plays an important role as it enhances super-storm cell development.
Some tornadoes can have wind speeds of up to 300 mph. A small storm could be as slow as 50 mph and last a few minutes. A large monster can last for several hours and travel as far as 250 miles.
On average, sixty people are killed by tornadoes each year. Boards, roof shingles, glass, stones, and bricks turn into missiles and cause most tornado-related deaths.
There is a major difference between a tornado and whatâs called a âfunnel cloud.â In a tornado, the damaging circulation is on the ground âwhether or not the cloud is. A true funnel cloud rotates, but has no ground contact. However, a funnel cloud is still dangerous and you should still avoid it! Some funnels may never touch the ground. As the funnel descends, the rotation speed increases. It becomes a tornado when it touches the ground and dramatically increases in speed and power as it feeds on the warmer surface air. If you see one, you should report it to either the local police, fire, or sheriffâs department, as well as your local office of the National Weather Service.
Where Is Tornado Alley?
National Oceanic and Atmospheric Administration/Department of Commerce
Even though we know most tornadoes occur during the spring and summer, there is no âtornado seasonâ (though there is a hurricane season). Still, there are certain times and areas where tornadoes are most likely to occur. From Texas to Oklahoma, through Arkansas to Illinois, through Nebraska to the Dakotas is the area that is called tornado alley , where most tornadoes are likely to occur during any given year. Looking at the map , however, you can see that if you live anywhere from South Dakota to most of Texas, from eastern Colorado to the eastern edges of the Midwest, you have a greater chance of experiencing a tornado than if you live in the Northeast, or mid-Atlantic, or on the Pacific coast. Itâs all but guaranteed that if you live in Oklahoma or Texas you will experience at least one tornado every one or two years.
Tornado Swarms
It is the rarest of storm types, but the super cell is the most dangerous because of the extreme weather it can generate. Since super cells can travel as far as 300 miles, multiple numbers of tornadoes can be created. This doesnât always occur, but when it does, these are called âswarmsâ of tornadoes. Super cells can be regenerated over a period of days along a cold front or what is called a squall line (a moving line of severe weather across a major portion of the country).
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Ten Greatest Tornado Swarms
NUMBER OF TORNADOES
DATE
DEATHS
148
April 3â4, 1974
315
111
September 19â23, 1967
5
99
May 26â27, 1973
22
95
November 21â23, 1992
26
94
May 4â5, 2003
37
85
May 22â23, 2004
1
80
February 5â6, 2008
60
80
May 18â19, 1995
4
78
May 3â4, 1999
46
70
May 11â12, 1982
2
67
April 26â27, 1994
3
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Top Ten: U.S. Cities Most at Risk for Tornadoes
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1. Oklahoma City, Oklahoma
2. DallasâFt. Worth, Texas
3. Lubbock, Texas
4. Kansas City, Missouri
5. Indianapolis, Indiana
6. St. Louis, Missouri
7. Jackson, Mississippi, and Birmingham, Alabama
8. Little Rock, Arkansas
9. Omaha, Nebraska
10. Chicago, Illinois
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Most Tornado-Prone Areas in the United States
Highest Absolute Number of