Thunderstorm intensity as determined from satellite data.

Abstract

Digital infrared data from a geosynchronous satellite (SMS 2) on 6 May 1975 are used to study thunderstorm vertical growth rates and cloud top structure in relation to the occurrence of severe weather (tornadoes, hail and high wind) on the ground. All thunderstorms from South Dakota to Texas along a N-S oriented cold front are monitored for a 4 h period with 5 min interval data. Equations are derived relating the thunderstorm growth rate to vertical velocity and outflow layer divergence. Severe thunderstorm elements are shown to have mean vertical velocities approximately twice as large as the non-severe elements. The outflow layer divergence is calculated to be 1 x 10-3 s-1 for the severe thunderstorms.-from Authors