Scientists measure tornadoes by the damage theycause. On the Fujita scale, named after Ted Fujita of theUniversity ofChicago, anFO storm doeslight damagewith windsbetween 64 and116 kph. Theworst tornado,at level F5, doeshorrible damage with winds starting at 419 kph.The clouds in the sky are spinning swiftly, and aconfused bird flies in front of Gene Rhoden's car. Andthen a part of one cloud lowers and gathers into the shapeof a funnel.? It spins like an angry ghost, no more than3 kilometers from the storm chasers, looking like an alienhas come to Earth. The storm chasers are moving closer tothe storm.