In Twister, the device used to study tornadoes is called Dorothy. It is a fictional instrument designed to release hundreds of small sensors into a tornado, allowing storm chasers to collect data from inside the storm.
Bill Harding originally developed the concept, and Jo Thornton’s team spends the film trying to deploy successive versions of it. The sensors are carried in a barrel-like container and are meant to be lifted into the vortex, where they can measure conditions such as wind behavior and pressure. The team hopes the data will improve tornado science and eventually contribute to earlier warnings.
Dorothy was inspired by a real 1980s research device called TOTO, or the TOtable Tornado Observatory. TOTO was a portable weather station built to be placed near a tornado, but it proved too unstable and dangerous for close-range deployments. Dorothy is therefore not the real machine’s name, and “Toto” is a deliberate reference rather than the answer to the film question. The movie also shows later prototypes named Dorothy II, Dorothy III, and Dorothy IV.