A rotating updraft in a supercell thunderstorm that can help produce tornadoes is a mesocyclone.
A mesocyclone is a broad, storm-scale region of rotating, rising air inside a powerful thunderstorm. It is much larger than the tornado that may develop within it, commonly spanning roughly 2–6 miles (3–10 kilometers). Doppler weather radar detects it through organized rotation at several heights.
Supercells are defined by a deep, persistent rotating updraft, and mesocyclones are central to that structure. Wind shear tilts horizontally rotating air upward, while the updraft concentrates the rotation. Interactions with the rear-flank downdraft can help create the low-level rotation and focused inflow needed for tornadogenesis.
A common mix-up is treating a mesocyclone as a tornado. A mesocyclone is the larger rotating storm feature; a tornado is a much narrower vortex that reaches the ground. Not every mesocyclone produces a tornado, and some tornadoes form through other processes.