This mega-eclair pushes all records: never a phenomenon of such a size has been spotted!

A flash that occurred in the United States, in the Grandes Plains in Texas, broke a world distance record. The facts date back to 2017, but it is only on July 31, 2025, in a report published in the Bulletin of the American Meteorological Societythat scientists have ocumented this impressive record.

A flash as long as the distance separating Paris from Venice

This flash extended over no less than 829 km (with an estimated margin of error at more or less 8 km), starting from eastern Texas until almost reaching Kansas City. Or the distance also separating Paris from Venice, the equivalent of 9 hours of car and at least 90 minutes by plane, told us the press release from the World Meteorological Organization (OMM). The fact that this flash exceeds the 100 km of distance traveled allows it to attribute the label of “Méga Éclair”.

Why only talk about it today? Because at the time, technologies had not made it possible to spot it. A press release from the Arizona University explains that, until then, the measures were carried out from “Floor antennas networks which detect the radio signals issued by lightning, then estimate the location and the speed of movement according to the time necessary for the signals to reach the other antenna stations of the network”.

Geostationary satellites to study mega-eclairs

Since then, satellite lightning detectors have developed. “Our meteorological satellites are equipped with very demanding lightning detection equipment that we can use to document Milliseconde when a lightning begins and how far it moves”, said Randall Cerveny, OMM rapporteur for meteorological and climatic extremes at the University of Arizona.

In 2017, this specific storm was one of the first in which the Geos-16 geostationary orbit satellite of the American administration for the oceans and the atmosphere (NOAA), collected data on thunderstorms and mega-eclairs.

« The addition of continuous measures from the geostationary orbit was a major advance ”said Michael Peterson, the first author of the article, in the press release from the University of Arizona. “We are now at a point where most world hot spots in lightning mega are covered by a geostationary satellite, and data processing techniques have improved to correctly represent lightning in the large amount of observation data at all scales”.

The lightning mega come from storms for 14 hours or more and very large, comparable to certain states of the United States. It is also not uncommon for lightning to strike several kilometers from its original cloud, explains Randall Cerveny. “This is why you should wait at least half an hour after the passage of a thunderstorm before going out and resume your normal activities”he specifies. “The storm that produces a love at first sight does not need to be above you” To be dangerous.

The last record set by a flash dates back to April 2020 during a storm in the south of the United States. The mega-light had then crossed a distance of 768 km.

“Over time and as observation data continues to accumulate, we will even be able to observe the rarest extreme lightning on earth, while studying the magnitude of the repercussions of these phenomena on our society”concluded Michael Peterson in the OMM press release.