Though it struck over the U.S. years ago, experts have only recently determined that a lightning flash that extended from Texas to Missouri back in October 2017 was actually the longest in recorded history.
In a Thursday press release, the World Meteorological Organization revealed that the “megaflash” was 515 miles long, extending from eastern Texas to Missouri, crossing Oklahoma. It would take a car eight hours to drive the total distance of the flash and even a commercial plane 90 minutes to fly it.
According to the WMO, that area where the flash occurred is a “notorious storm hotspot” for megaflashes in the Great Plaines. When the record-breaking lightning lit up the sky in 2017, there was a major thunderstorm complex churning through the region.
Analysis and re-examination of this storm eventually uncovered the 515-mile flash, since it was not identified back in 2017. WMO’s Committee on Weather and Climate Extremes recognized the new record with the help of the satellite technology and the findings were published in the Bulletin of the American Meteorological Society.
Maximum great circle distance methodology was used to measure the flash. Furthermore, the storm it was part of was one of the first to have its megaflashes documented using the National Oceanic and Atmospheric Administration’s newest Geostationary Operational Environmental Satellite (GOES-16).
“This new record clearly demonstrates the incredible power of the natural environment. Additionally, WMO assessment of environmental extremes such as this lightning distance record testify to the significant scientific progress in observing, documenting and evaluating such events. It is likely that even greater extremes still exist, and that we will be able to observe them as additional high-quality lightning measurements accumulate over time,” said Professor Randall Cerveny, rapporteur of Weather and Climate Extremes for WMO.
Previously, the record for the longest lighting flash was around 477 miles long, per the WMO. It occurred across parts of the southern U.S. on April 29, 2020.
Timothy Logan of the Houston Lightning Mapping Array network (HLMA) and assistant professor at Texas A&M University remembers that night, according to the school.
“The HLMA helped determine the origin of the megaflash and the GOES-16 satellite helped monitor the whole distance of it,” he said. “Randall Cerveny, Michael Peterson, and Timothy Lang, who analyzed the geostationary lightning mapper data from the GOES-16 satellite, reached out to me and asked me to help confirm the megaflash with the HLMA.”
While these lightning records are impressive, experts also warn of the dangers associated with lightning flashes.
Another lightning-related extreme noted by the WMO include the greatest duration for a single lightning flash (around 17 seconds) during a thunderstorm over Uruguay and northern Argentina in June 2020. There was also a single direct strike in 1975 that killed 2 people in Zimbabwe and an indirect strike that hit oil tanks and killed 469 people in Egypt 31 years ago.
“Lightning is a source of wonder but also a major hazard that claims many lives around the world every year and is therefore one of the priorities for the international Early Warnings for All initiative. These new findings highlight important public safety concerns about electrified clouds which can produce flashes which travel extremely large distances and have a major impact on the aviation sector and can spark wildfires,” said WMO Secretary-General Celeste Saulo.