BOB DOUGHTY: Tornado seasons are the result of wind and weather patterns. During spring, warm air moves north and mixes with cold air remaining from winter. In autumn, the opposite happens. Cold weather moves south and combines with the last of the warm air from summer.
A series of tornadoes over two days in March killed 40 people in Kentucky, Alabama, Indiana and Ohio
Tornadoes can strike with little or no warning. Most injuries happen when flying objects hit people. Experts say the best place to be is in an underground shelter, or a small, windowless room in the lowest part of a building.
People driving during a tornado are told to find low ground and lay flat, facedown, with their hands covering their head. People in the path of a tornado often just have minutes to make life-or-death decisions.
BARBARA KLEIN: The deadliest American tornado on record was the Tri-State Tornado of March eighteenth, nineteen twenty-five. It tore across Missouri, Illinois and Indiana. About seven hundred people were killed.
Between March and May of last year, there were one thousand one hundred fifty-nine confirmed tornadoes across the United States. Scientists say that is the most on record for any three-month period. The most active month was last April, when seven hundred fifty-eight tornadoes were confirmed. That is the most ever for any month.
Last April, the country also broke a thirty-seven year old record for the largest tornado outbreak. A "tornado outbreak" is often defined as six or more tornadoes produced by the same weather system within a day.
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2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25
2013-11-25