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。
2
In the background is the cloud (white), from which the tornado formed.
背景之中的云(白色)是龙卷风的风源。
3
The calm in the center of an incomplete tornado allows the cloud cover to remain in place, where at the edges of the swirl the cloud cover is torn away.