Twister is a 1996 American disaster drama film starring Helen Hunt and Bill Paxton as storm chasers researching tornadoes. It was directed by Jan de Bont from a screenplay by Michael Crichton and Anne-Marie Martin. Its executive producers were Steven Spielberg, Walter Parkes, Laurie MacDonald and Gerald R. Molen. Twister was the second-highest-grossing film of 1996 domestically, with an estimated 55 million tickets sold in the US.

In the film, a team of storm chasers try to perfect a data-gathering instrument, designed to be released into the funnel of a tornado, while competing with another better-funded team with a similar device during a tornado outbreak across Oklahoma. The plot is a dramatized view of research projects like VORTEX of the NOAA. The device used in the movie, called "Dorothy", is copied from the real-life TOTO, used in the 1980s by NSSL.