Anatomy of a tornado


  • Anonymous


Specially equipped Doppler radars enabled scientists at NOAA's Environmental Research Laboratories (ERL) and at the Sperry Corp. to measure, for the first time, the size, speed, and power of a tornado. The radar, aimed at a tornado north of Binger, Okla., last May, revealed a vase-shaped funnel, about 975 m thick near its base, that widened to about 1609 m about one third of the way up and then narrowed at the top; the width of the tornado averaged about 800 m during its 22.5-km journey. The 12-km-high twister generated winds up to 315 km/h and was powerful enough to have picked up and hurled from its funnel cattle, farm combines, a semi-trailer truck, and oil storage tanks, among other debris, at 69 km/h, report Donald Burgess, Larry Hennington, and Dusan Zrnic at ERL and Leslie Lemon of the Sperry Corp. The researchers also discovered a ‘hole’ in the radar echoes, indicating a portion of the tornado that is almost devoid of precipitation, dust, or other objects that reflect radar beams.