SEARCH

SEARCH BY CITATION

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.