Tornado Season Returns
May 28, 2013
Workers clear damage from Oklahoma tornado.
From VOA Learning English, this is SCIENCE IN THE NEWS. I'm Faith Lapidus.
And I'm Bob Doughty. This week, we explore the science of tornadoes. Weather experts say tornadoes are the most violent of all atmospheric storms. They strike in many parts of the world, including the United States.
Tornado season has begun in the United States.
A series of violent storms moved through north-central Texas in the middle of May. Some storms struck the small community of Granby, south of the Dallas-Fort Worth area. At least six people were killed. The tornadoes flattened or caused heavy damage to many homes.
Less than a week later, a large tornado caused major damage in the neighboring state of Oklahoma. The three kilometer wide tornado destroyed homes, businesses and two schools in Moore, just outside Oklahoma City. Officials say the storm left more than 20 people dead, and injured more than 200 others.
In May 1999, another deadly tornado hit Moore. It was one of more than 70 tornadoes reported in Oklahoma and Kansas in just 21 hours.
A tornado is a violently turning tube of air suspended from a thick cloud. It extends from a thunderstorm in the sky down to the ground. The shape is like a funnel: wide at the top, narrower at the bottom.
Tornadoes form when winds blowing in different directions meet in the clouds and begin to turn in circles. Warm air rising from below causes the wind tube to reach toward the ground. Because of their circular movement, these windstorms are also known as twisters.
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