Why do tornadoes spin?

Answer: Wind shear creates rotation

Earth's rotation makes them spin — Wrong. Earth's rotation (Coriolis effect) affects large systems like hurricanes but is too weak to create tornadoes. Tornado spin comes from wind shear - winds at different heights moving in different directions.

Wind shear creates rotation ✓ — Correct! Tornadoes form when winds at different heights blow in different directions or speeds (wind shear). This creates a horizontal spinning effect. When a powerful thunderstorm updraft tilts this rotation vertical and tightens it, a tornado forms. As the spinning column narrows (conservation of angular momentum), it spins faster - like a figure skater pulling in their arms!

Lightning creates spinning air — Wrong. Lightning is an electrical discharge and doesn't create spinning air. Tornado rotation comes from wind shear - different wind speeds at different heights creating rotation that gets tilted and tightened by updrafts.