Most tornadic storms rotate cyclonically, but a few rotate anticyclonically.
Jones indicates that the difference is tightly related to the vertical shear of ambient winds relative to the motion vector of the storm. When the vertical shear of the environmental wind is large, updrafts rotate cyclonically and downdrafts anticyclonically when the storm-relative winds veer with height in the lowest 3 km. We have already mentioned the importance of winds changing their velocities with height. Veering is important for setting the stage for severe weather. Varying strengths and configurations of the vertical wind profile and resulting shear determine the nature of the storms that form, whether they are single cells, multicells or supercells.