Lightning bolt that stretched 768km across three US states sets new world record

A lightning bolt that stretched for 768 kilometres across the southern United States in 2020 is the new world record holder for the longest single flash, according to the World Meteorological Organization (WMO).

The flash extended across the states of Texas, Louisiana and Mississippi on April 29, 2020, beating the previous record set on October 31, 2018, in Brazil of 709km, the agency said.

The findings by WMO’s Committee on Weather and Climate Extremes were published in the Bulletin of the American Meteorological Society.

Professor Randall Cerveny, rapporteur of weather and climate extremes for WMO, described the two records as “extraordinary”.

“Environmental extremes are living measurements of the power of nature, as well as scientific progress in being able to make such assessments,” he said. “It is likely that even greater extremes still exist, and that we will be able to observe them as lightning detection technology improves.”

Ron Holle, lightning specialist and committee member, said, “These extremely large and long-duration lightning events were not isolated but happened during active thunderstorms. Any time there is thunder heard it is time to reach a lightning-safe place.”

He added: “The only lightning-safe locations are substantial buildings that have wiring and plumbing; not structures such as at a beach or bus stop. The second reliably safe location is inside a fully enclosed metal-topped vehicle; not dune buggies or motorcycles.

“If lightning is within 10km as found with reliable lightning data, go to the lightning safe building or vehicle. As these extreme cases show, lightning can arrive within seconds over a long distance, but they are embedded within larger thunderstorms, so be aware.”