In 1969, a young girl named Jo is awakened in the night by an approaching F5 tornado and witnesses her father get killed by the storm as he tries to save his family. In the present day (1996), adult Jo is an eccentric meteorologist obsessed with chasing tornadoes and leads a team of ragtag storm chasers, but is on the brink of divorce with her ex-husband, retired storm chaser-turned news anchor Bill Harding. Bill ventures to rural Oklahoma to meet Jo for the first time in months and finalize their divorce papers, bringing with him his new fiancé, therapist Melissa Reeves. Though Bill would like to get the papers signed as quickly as possible before leaving, he is intrigued by Dorothy 1-4, an invention he developed but never saw come to fruition. Dorothy would be revolutionary to tornado research and safety measures, but to use it properly means for it to be placed as dangerously close to a tornado as possible. Jo's team suddenly rushes to chase a tornado forming nearby, but Bill and Melissa are forced to pursue Jo when she mistakenly takes the papers with her. However, Bill has a run-in with Jonas Miller, a fellow rival storm chaser whom he has negative history with, and is run off the road by Jonas's team.