What is a multiple vortex tornado?

A multiple vortex tornado is a tornado that has two or more smaller vorticies inside the main circulation. These subvorticies or suction vortices can have winds up to 100 mph faster than the rest of the tornado, and thus cause more severe damage. This is one reason why one area hit by a tornado may only sustain moderate damage, while the area next to it may be devastated. Normally these vortices are hidden within the main funnel, but if conditions are right a multiple vortex tornado may have two or more funnels. Each subvortex usually only lasts a few seconds.