When Samantha “Sam” Callen (Shannon Sturges) gets off the plane in Byron, Texas, her assignment from the National Accounting Office is to pull the plug on the tornado project of Dr. Branson (Ernie Hudson). He has created a machine named PATTI to gather information from within a tornado that will help track and predict future storms. Six years into the project, Dr. Branson is just now ready to test PATTI. Not completely unsympathetic, Sam plans to give Dr. Branson a few days to fine-tune his machine. Dr. Branson and Sam drive into town with Jake Thorne (Bruce Campbell), a handsome, cocky, tornado-chasing cowboy who works with Dr. Branson. Despite an involuntary mutual attraction, Sam and Jake get off to a start that’s bumpier than the road they’re driving on. Lodging at the Thorne farm, Sam meets Ephram (L.Q. Jones), Jake’s grand-father, whose devastating childhood experience has left him passionate about tornadoes. When a funnel cloud is spotted heading toward a nearby town, the team gives chase. Sam is flushed with adrenaline and drawn into the excitement of the dangerous pursuit. When the tornado takes a sudden change in course, they witness its brutal power as it destroys a small community. Helping the survivors, Sam begins to understand the importance of Dr. Branson’s work. The experience also draws Jake and Sam together and, now personally involved, Sam wants to help Dr. Branson. Barely recovered from the first disaster, Jake receives word that a monstrous twister is brewing nearby. Sam immediately joins him in the chase. With devastating force, the maelstrom descends directly upon the Thorne farm, where it affords Dr. Branson an opportunity to use PATTI. At the same time, however, Sam, Jake and Ephram find themselves directly in the vortex of the twister, facing death.