Water is heated in a pan to both produce heated air which rises and steam that condenses in the rising air column. Plexiglas panels can be slid left or right to admit the room air with a clockwise or counterclockwise motion. The air spirals tighter toward the center and creates a visible column, similar to a tornado vortex. Cigarette smoke is admitted to both trace the air flow and to act as condensation nuclei for cloud formation. Small blades supported on smoke tubes allow the spin rates to be measured at differing distances from the center of the vortex.