The electron trapping characteristic of a solid dielectric material (polymethylmethacrylate) is exploited to study electrical discharge propagation in laboratory-scale space charge clouds. Similarities with the static and dynamic behaviors of thundercloud electricity are identified, and a combination of theoretical and empirical scaling relationships enables a rough translation of parameters from laboratory scale to thundercloud scale. Applications of the laboratory technique to specific thunderstorm situations reinforce the value of discharge structure studies in exposing the very important space charge configuration that gives rise to lightning.