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Somebigstrongtornadoesmayhavesmallermore intense "suctionvortices" that spin around the center of the tornado. Tornadoresearchers have actually seen the pattern shown at rightscratched into the ground by the multiple vortices in a strong tornado.
Thehomesmarkedinredwouldbedamaged severely. The otherswould receive less damage. Remember that there are multiplesuction vortices in the tornado, but the tornado diameter is probablylarger than shown here.
Air motions inside tornadoes arecomplex and difficult to study directly. Researchers resort tolaboratory simulations and computer models. The figures belowshow some of the air motions thought to occur in tornadoes.
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This tornado is a little stronger.
This tornado is evenstronger. The air in the center has started to sink (this iscalled vortex breakdown), but the sinking air doesn't reach theground. The diameter of the tornado has also grown.
It is when the sinking air in themiddle reaches the ground that multiple vortices may form.
