829 Kilometre Lightning Bolt sets world record

Credit: From WMO

Scientists have confirmed that a colossal lightning bolt that stretched 829 kilometers from Texas to Missouri in October 2017 officially holds the world record as the longest single flash ever recorded. The World Meteorological Organization certified the megaflash after a reanalysis of satellite data revealed the unprecedented scale of the electrical discharge.

The massive bolt lasted 7.39 seconds and spawned at least 116 cloud-to-ground spikes along its length as it coursed through a thunderstorm system across the U.S. Midwest. It surpassed the previous record by 61 kilometers, besting a 768-kilometer bolt that stretched across Texas, Louisiana, and Mississippi in April 2020.

Advanced Satellite Technology Enables Discovery

The record-breaking lightning remained hidden for almost a decade until researchers re-examined data from the National Oceanic and Atmospheric Administration's GOES-16 satellite. The satellite, equipped with a Geostationary Lightning Mapper that observes about one million bolts per day, made the discovery possible through continuous monitoring from geostationary orbit.

"Adding continuous measurements from geostationary orbit was a major advance," said Michael Peterson of Georgia Tech Research Institute, who led the study published in the Bulletin of the American Meteorological Society. "We are now at a point where most of the global megaflash hotspots are covered by a geostationary satellite."

Understanding Megaflash Formation

Megaflashes occur in fewer than one percent of thunderstorms and require specific conditions to form[1][2]. The storms must churn for at least 14 hours and cover an area at least the size of New Jersey to produce these extraordinary electrical discharges[2].

"When they can't go up anymore, they go out," Peterson explained, describing how charged particles reach the upper boundary of Earth's troposphere and spread horizontally[2]. This creates massive, thin charged layers that serve as key ingredients for megaflashes.

Randy Cerveny, an Arizona State University professor and WMO rapporteur for weather and climate extremes, noted that researchers are still unraveling the mechanics behind these phenomena[1]. "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," he said[3].

Citations:

[1] New world record! Weather satellites detect 515-mile-long lightning flash https://www.space.com/astronomy/earth/new-world-record-weather-satellites-detect-515-mile-long-lightning-flash

[2] A Midwest 'megaflash' is the longest lightning on record https://www.sciencenews.org/article/longest-lightning-midwest-megaflash

[3] New world record set for longest ever ‘megaflash’ lightning https://cosmosmagazine.com/earth/earth-sciences/record-megaflash-lightning/