Lightning flash measuring 768 kilometres is the longest ever recorded
The world’s longest lightning flashes – both in terms of the distance covered and duration – have been measured from space and confirmed by the World Meteorological Organization (WMO). One of the flashes occurred in the southern US in April 2020 and had a length of about 768 kilometres, or the distance from London to Hamburg, which is 60 kilometres longer than the previous record set in Brazil in 2018. The second flash was measured in June 2020. It straddled the Uruguay-Argentina border, and lasted for 17 seconds - longer than any other flash ever detected. “We now have clear proof that single lightning events can last seventeen seconds,” says Randall Cerveny at Arizona State University. “This is important to scientists because it improves our understanding of the dynamics of lightning – how, where and, importantly, why lightning occurs the way it does.” Both flashes were seen in thunderstorm hotspots, in the Great Plains of North America and the Río de la Plata basin in South America. These geographies are prone to relatively large convective systems, which can cause individual thunderstorms to combine into massive weather systems that trigger extreme lightning strikes. The flash that spanned the southern US would have been difficult to measure with conventional ground-based equipment, so meteorologists turned to lightning mappers on geostationary satellites, which have a far wider field of view.