Bill and Jo Harding, advanced storm chasers on the brink of divorce, must join together to create an advanced weather alert system by putting themselves in the cross-hairs of extremely violent tornadoes.

Director Jan de Bont wanted to shoot the tornadoes with a handheld camera on location for this fictional story as if he were filming a documentary.

One problem: the tornadoes would be digital and added in post-production.

Rather than restrict the director to filming actors using a locked-off camera, which was the common approach at the time and would have made post-production easier, ILM set De Bont free by creating extreme digital effects. A custom interface for a new software system called Dynamation that could control massive amounts of particles made it possible for the technical crew at ILM to produce the digital tornadoes into which they inserted spinning digital cows, furniture, and other CG objects.

1997 Academy Award® nominee for Best Visual Effects and BAFTA Award winner for Best Special Visual Effects.

Director
Jan de Bont
ILM Visual Effects Supervisor
Stefen Fangmeier
ILM Animation Director
Scott Benza
ILM Visual Effects Art Director
Guy Hendrix Dyas
ILM Visual Effects Producer
Kim Bromley
Michael J. Halsted
Jeanie King