Tornadoes; Forces of Nature; Exclusive Online Issues; by Robert Davies-Jones; 5 Page(s)

This spring was a frenzied tornado season in the U.S. In May alone, an estimated 484 tornadoes killed some 16 people and ravaged millions of dollars of property. Day after day, forecasts of severe storms sent me and my colleagues rushing from the National Severe Storms Laboratory (NSSL) in Norman, Okla., to Texas or Kansas, returning sometimes at three in the morning. After the day's briefing at 9 A.M., we might set off again, fatigued but hoping once more to collect precious data on the birth of tornadoes.

On Tuesday, May 16, the weather maps revealed the threat of afternoon tornadoes in Kansas. By 5 P.M. a menacing thunderstorm had erupted, fed by warm, moist southerly winds that rose and rotated in an updraft. The storm was a highly organized "supercell," an ideal tornado breeding ground. As William Gargan, a graduate student at the University of Oklahoma, and I approached from the southeast in our instrumented car, called Probe 1, we glimpsed the 10-mile-high top of the monstrous storm, 60 miles away. The thunderstorm was sweeping eastnortheast at 30 miles per hour, a quite typical motion in the Great Plains.