Tornadoes are probably the most frightening and most fascinating kind of weather system.
To understand how a tornado works, try the following experiment. Fill one bottle three-quarters of the way with water. Put the openings of the bottles together so that the empty bottle is turned upside down on top of the water-filled one. Seal them together by fastening the openings with duct tape. Turn the bottles over and rotate the water-filled bottle on top to get the tornado started.