Stormy Weather


What is a multiple-vortex tornado?

Sometimes a central tornado can be surrounded by smaller tornadoes called sub-vortices or suction vortices. There can be as many as seven subvortices surrounding the central tornado, though two to five is more common. Interestingly, these smaller tornadoes tend to be more intense, with winds spinning at about 100 miles (160 kilometers) per hour or more faster than the central vortex.

A wind speed instrument mounted on a Project Vortex vehicle monitors conditions in northern Texas in this 1994 photo. (NOAA Photo Library, NOAA Central Library; OAR/ER National Severe Storms Laboratory)

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