Storm chasing is broadly defined as the intentional pursuit of a thunderstorm, regardless of motive. A person who storm chases is known as a storm chaser, or simply a chaser. While witnessing a tornado is the biggest objective for a chaser, many delight in seeing cumulonimbus structure, watching a barrage of hail, and seeing what skyscapes unfold.

Storm chasing is almost always a recreational endeavor, with motives usually given toward photographing the storm for personal reasons. Though scientific work is sometimes cited as a goal, such work is almost always impractical except for those participating in a university or government project. Storm chasers are not paid to chase, with the exception of television media crew in certain television markets, and a handful of graduate meteorologists and professors. A few entrepreneurs, however, manage to sell storm video and pictures or operate "chase tour" services.

The very first storm chaser is generally agreed to be Roger Jensen (1933–2001), a Fargo, North Dakota native who pursued western Minnesota storms from Lake Park around 1951. David Hoadley (1938– ) began chasing North Dakota storms in 1956, systematically using data from area weather offices. Bringing research chasing to the forefront was Neil Ward (1913–1972) who in the 1950s and 1960s enlisted the help of Oklahoma state police to study storms. His work pioneered storm spotting and made institutional chasing a reality.

In 1972 the University of Oklahoma in cooperation with the National Severe Storms Laboratory began the Tornado Intercept Project. This was the first large-scale chase activity sponsored by an institution. It culminated in a brilliant success in 1973, with the Union City, Oklahoma tornado providing a foundation for tornado morphology. The project produced the first legion of veteran storm chasers, with Hoadley's Stormtrack magazine bringing the community together in 1977. Storm chasing then reached popular culture in three major spurts: in 1978 with the broadcast of a segment on the television program In Search Of; in 1985 with a documentary on the PBS series Nova; and in May 1995 with the theatrical release of Twister which provided an action-packed but comically distorted glimpse at the hobby.

Storm chasers are most active in May and June across the Great Plains, with perhaps a hundred individuals active on any given day. Some organized chasing efforts have also begun in southeast Australia, with the biggest successes in November and December.

See also

• Hurricane