Abstract
Experimental lightning detectors on two DMSP satellites have recorded lightning data in near coincidence (within 30 min) with tornado touchdown for 14 severe storm complexes between August 1977 and May 1979. Lightning trigger rates from these storms, averaged over the synoptic-scale (650 km radius) field of view of the sensor, are compared with trigger rates from 61 non-tornadic storms. The two trigger-rate distributions differ at the 99% confidence level, and the mean trigger rate for the tornadic storms is at least two standard deviations above the mean rate for non-tornadic storms (at 95% confidence level). Increased lightning activity is apparent some 30 min before tornado touchdown.
