Tornado dynamics. Artwork of a tornado causing destruction to houses in a farmland plains area, with arrows showing the direction of the tornado's movement and rotation. A tornado is a rapidly rotating funnel of air that can form below certain types of storm clouds, and can be accompanied by lightning and rain. If it touches the ground, the high wind speeds in the rotating funnel can cause immense destruction, throwing up a cloud of debris. Large and powerful tornados can have wind speeds of over 200 kilometres per hour, be many metres wide at their base, destroy houses and trees, and kill people in their path. Tornados often form as weather fronts collide over large plains, such as the Great Plains of the USA.