Randall Cerveny
Professor Cerveny is a faculty member at the School of Geographic Sciences and Urban Planning at Arizona State University, USA. He also serves as Rapporteur on Extreme Records for the United Nations and World Meteorological Organization, and in this role is responsible for researching and verifying global weather records. He is contributing editor for the magazine Weatherwise, and has authored journal articles and several books on the topics of climate and meteorology including Judging Extreme Weather (2024).
Longest lightning flash
A single lightning flash spanned a horizontal distance of 768 km, plus or minus 8 km (477.2 miles, plus or minus 5 miles), crossing the US states of Mississippi, Louisiana and Texas, on 29 April 2020. The event was verified by the World Meteorological Organization on 1 February 2022. This is equivalent to the distance between New York City and Columbus Ohio in the United States or between London and the German city of Hamburg.
This new record for the longest detected "megaflash" distance is 60 km (37 miles) farther than the previous record. Typically, the length of lightning bolts is around 9 km (5.5 mi) or below. Showing how far we have come in measuring the phenomenon of megaflashes, in 1956 meteorologist Myron Ligda observed and recorded a lightning flash, using radar, that covered a horizontal distance of 149 km (93 mi) inside clouds.