The mesoscale convective systems (MCS) are one of the greatest lightning producing weather systems in the continental United States. The lightning flash rates from an individual MCS typically exceed 1000 flashes per hour, lasting for several hours. Collaborating with Dr. MacGorman of the National Severe Storms Laboratory, Professor Rutledge will examine the relationship between the position and polarity of lightning strikes and the dynamical and microphysical structure of the mesoscale convective systems. Data to be exploited include those collected by the lightning detection finders and dual Doppler radars, as well as satellite infrared measurements made during the PRE-STORM project, which took place in Oklahoma and Kansas during May-June 1985. This joint, unambiguous treatment of lightning activities and the evolution of mesoscale convective systems is a first of its kind.