Robert Henson Writer/Editor University Corporation for Atmospheric Research Boulder (CO), USA The Chase Is On

For storm scientists and dedicated amateurs, chasing tornadoes is more than Hollywood fiction. SON COPYRIGHT ROBERT HEN

Tornado in south-central Nebraska May 24, 2004.

hile teaching a me- Floods, construction, and traf- chasing. The largest such project, teorology class for a fic are among the many hazards dubbed VORTEX, took place W group of Vaisala em- that impede storm chasing. A from Texas to Kansas in 1994– ployees in Louisville, Colora- successful chaser calls on exten- 95. A follow-up is being planned do, I was reminded of the pow- sive knowledge of storm behav- for later this decade. Porta- er of the . Discussing se- ior and skills that include navi- ble Doppler radars mounted vere weather caught people’s at- gation, observation, communi- on trucks are a vital part of this tention and triggered interesting cation, and physical intuition. work. One such radar measured questions. wind speeds of more than 460 It is no surprise that the Serving km/hr just above ground level springtime parade of thunder- Storm chasing for research began during a deadly Oklahoma tor- storms is so compelling. Yet even in Oklahoma and Texas in the nado outbreak in May 1999. residents of the U.S. 1970s. They helped catalog visi- – home to more tornadoes than ble clues to storm behavior, such Amateurs on the trail any other place on Earth – can as low-hanging wall that Even before scientists started go a lifetime without seeing one. precede many tornadoes and chasing, amateurs were on the I grew up on the plains in Okla- lines of cumulus that extend like trail. David Hoadley began chas- homa City, but it was not until spokes from the rotating heart of ing on his own in the mid-1950s Robert Henson is the author of The I started storm chasing as a col- a storm. Reports from the field as a teenager in Rough Guide to Weather. (Photo courtesy of Carlye Calvin) lege student in 1980 that I saw also help when interpreting radar and still chases today. The 1997 my first tornado. Since then I data. In 1987, I spent a summer film “Twister” inspired hun- have seen more than 35 twisters with seven colleagues following dreds of nonscientists to take to while chasing as part of research storms across eastern Colorado. the Great Plains with video cam- projects and for my own photog- Each day we took note of the eras. Some of these newcomers volve more than 700 kilometers raphy. time and location of severe , join organized tours, where peo- of driving. Storms may not de- Driving alongside a severe tornadoes, and other weather ple from as far away as Japan velop until an hour before sun- is a humbling ex- features; meanwhile, the storms and Great Britain pay more than set, if at all. Still, those late-day perience. It is a small-scale phe- were being tracked by the pro- $1200 US a week for the chance moments when the atmosphere nomenon that often defies even totype unit for what would be- to see an elusive twister. comes alive can be spellbind- the best forecasters, changing come the U.S. network of Dop- Although it is glamorized ing. It is the grand sweep of a from minute to minute. Even pler radars. on television and in the movies, storm against the sky, twister or when a storm is well-behaved, Basic research on severe chasing offers far more boredom no twister, that brings me back the road network may not be. weather relies heavily on storm than excitement. Many days in- to the prairie each spring. ●

30 168/2005