High-speed video observations of natural cloud-to-ground lightning leaders - A statistical analysis

► Statistical distributions of two-dimensional speeds of stepped, dart and positive leaders are presented. ► An analysis of how the propagation speeds change as a leader approaches ground was made for all three types. ► No correlation was found between return stroke peak current and the average speed of the preceding leader for all types. ► Preceding interstroke intervals above 100 ms seem to limit the propagation speed of a dart leader to values below 107 m s− 1. ► The influence of recoil leader activity on the propagation of a positive leader and the following return stroke was analyzed.