EXCLUSIVE: Sarah Wayne Callies has signed on for the untitled Steve Quale tornado thriller at New Line. The Walking Dead actress will play the character of “Allison Stone” in the found-footage natural disaster film. Callies is not leaving Walking Dead, but instead will juggle the AMC series and the movie. Directed by Quale, (Final Destination 5 and second unit director on Avatar), the film was formerly known as Category 6. John Swetnam wrote the screenplay. Todd Garner is producing. Alycia Debnam-Carey also recently joined the film, which follows a group of high school teens dealing with the aftermath of a devastating tornado, as one of the female leads. Sarah Wayne Callies is repped by Paradigm with the firm of Sloane, Offer, Weber & Dern as her attorneys.