There have always been questions about how high wind speeds could get. Before recording the top wind speed, Wurman's team captured the birth of this violent tornado, which eventually passed through Oklahoma City. The researchers observed the storm for 8 minutes before the tornado's birth and then documented the first 6 minutes of its life. Tornadoes develop when winds high above the ground flow at a different speed than winds near the surface, causing the air to roll along a horizontal axis, like the wheels of a car. If a thunderstorm is brewing at the same time, updrafts and downdrafts can tilt the rolling winds so that they spin around a vertical axis, setting a broad region of the storm slowly rotating.
Meteorologists call such a storm a mesocyclone.
The data collected last week are expected to shed some light on that process and others, as different teams analyze their gigabytes of measurements. Bluestein and his coworkers studied some of the same Oklahoma storms using a Doppler radar with much higher resolution, designed by Andrew L. Pazmany of the University of Massachusetts at Amherst. Radar catches a tornado in the act . From Science News , Vol.