Continuity mistake: When the cow blows by the truck, the truck is driving down an empty dirt road with water on both sides. During the shots of the occupants, the road behind the truck is paved and dry. Also in one of these rear shots a truck (Red Chevrolet Blazer) drives by in the opposite direction.
Factual error: In the begining when Jo's dad is bringing the family downstairs and say's "TV says it's big, might be an F-5" That scene was set in 1969. In reality he would not have known anything about an F-5 or any tornado with an F rating because the Fujita scale was not developed until 1971.
Trivia: The oil tank truck that narrowly misses Bill and Jo's truck during the final tornado sequence bears the logo of the "Benthic Petroleum" company, a fictional company that also appeared in James Cameron's "The Abyss" - The same special effects company worked on both films.