Two flashes, one over Buenos Aires in Argentina and one above the Gulf coast of the United States, set new records. With 17.102 seconds duration, that over South America was the longest -lasting flash, which spanned the largest route in the USA with 768 kilometers. The two flashes already observed in April and June surpass the previous records from 2018 and 2019 by 0.37 seconds and about 60 kilometers, the World Organization for Meteorology (WMO) said today. Both flashes were created in gigantic thunderstorm complexes that often occur in these regions.
The discharges are not a single lightning channel, but tree-like branched structures with countless branches that extend over large areas. For example, a megalightning observed in 2019 covered an area of around 115,000 square kilometres. The WMO experts only know that such gigantic structures are individual lightning strikes because they were perceived from Earth orbit – the current record holders by weather satellites of the US system GOES-R. From the ground, such extended lightning would not be observed.
The previous record flashes were the first from space and in turn had more than doubled the records previously measured from the ground. Experts assume that even longer flashes occur than those now measured. The short observation period of a few years should not be enough to have already observed the most extreme possible discharges. The extent of such flashes is limited by the size of the thunderstorm systems in which they occur. Thunderstorm complexes referred to as mesoscible convective systems often arise from cold fronts. The largest of them can measure far more than 1000 kilometers.
