Thunderstorm: 829-kilometer mega-lightning breaks world record

Sometimes the sky catches fire for hundreds of kilometers. This is what happened on October 22, 2017, in the Great Plains region of the central United States, during a major thunderstorm .

A mega-lightning bolt of 829 kilometers was certified this Thursday, July 31, as the new record for the longest electric discharge ever recorded, announced the World Meteorological Organization (WMO). "Extending from East Texas to the outskirts of Kansas City, it covered a distance equivalent to that which separates the European cities of Paris and Venice," the WMO underlined in a press release .

Love at first sight

A committee of 11 experts based in the United States, Brazil, Germany, Spain, Nepal, and Israel certified this new record. The previous record (768 km), also recorded in the United States, took place between Mississippi and Texas on April 29, 2020, and was certified in 2022. These records have a margin of error of plus or minus 8 km.

The lightning flash seen on Thursday "was not detected during the initial analysis of the storm in 2017, but was discovered during a reassessment of the storm," the WMO explained. This episode was "one of the first storms during which the US National Oceanic and Atmospheric Administration 's (NOAA) newly launched Geostationary Exploration Satellite for Environmental Studies (GOES-16 ) collected data on mega-flashes, that is, thunderstorm discharges with extreme spatiotemporal length," the WMO added.

For the UN meteorological agency, such mega-flashes underscore the power and danger of lightning . "Lightning can travel very long distances away from the original storm ," explained Randall Cerveny, WMO rapporteur for weather and climate extremes. "That's why some people refer to it as blue lightning, lightning that appears to come out of a clear sky."

Randall Cerveny, a professor of geographical sciences at Arizona State University, established the WMO World Archive of Weather and Climate Extremes in 2007. It records global records for temperature, pressure, precipitation, hail , aridity, wind, lightning, and weather-related mortality.

Satellite lightning mapping has only been operational since 2016, too short a timeframe to determine patterns or trends in intensity, location, or frequency. "Give us another decade or so of data and we can start to address this question," Cerveny said.

As the data grows, "we will be able to observe even the rarest types of extreme lightning on Earth and study the broad impacts of lightning on society," said Michael J. Peterson of the Severe Storms Research Center in the United States.

The WMO is calling for early warning systems to be implemented across the globe to address all dangerous weather events . "Lightning is a source of wonder, but also a major hazard that claims many lives around the world every year," warned WMO chief Celeste Saulo.

According to lightning record figures validated by the WMO, the longest duration of a lightning flash is 17.102 seconds (on June 18, 2020, in Uruguay and northern Argentina), the deadliest direct lightning strike killed 21 people sheltering in a hut (in 1975, in Zimbabwe) and the most devastating indirect impact is the spillage of burning fuel after impact on a depot, killing 469 people (in 1994, in Dronka, Egypt).