Tornado chasers there spent seven hours and 150 miles (240 kilometers) tracking the supercell thunderstorm that produced this cloud formation.

那里的龙卷风追风人历经七小时，行程240公里，追逐这个由超级单体雷暴形成的云体，拍下了精彩的图片。

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And in the most extreme cases, a violent tornado is born beneath that spinning white cloud of updraft that meteorologists call the supercell thunderstorm.

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In Oklahoma, storm chasers with cameras in their cars transmitted video showing a number of funnels dropping from the supercell thunderstorm as it passed south of El Reno and into Oklahoma City just south of downtown.

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