A multiple-vortex tornado is a tornado that contains several vortices (called subvortices or suction vortices) revolving around, inside of, and as part of the main vortex. The only times multiple vortices may be visible are when the tornado is first forming or when condensation and debris are balanced such that subvortices are apparent without being obscured. They can add over 100 mph to the ground-relative wind in a tornado circulation and are responsible for most cases where narrow arcs of extreme destruction lie right next to weak damage within tornado paths.[1]
- ^ Elite Spotter Workshop crh.noaa.gov Archived 8 August 2010 at the Wayback Machine