Scientists have detected a record-breaking lightning bolt that was 321.1 kilometers (199.5 miles) in length, roughly the distance between New York City and Washington D.C. It streaked across the skies above Oklahoma back in 2007, and the World Meteorological Organization (WMO) has just officially recognized it as the longest single flash of lightning ever recorded.
At the same time, they also confirmed another record. Striking over southern France in 2012, a lightning bolt managed to sustain its connection between the ground and the heavens for a whopping 7.74 seconds. The average duration is just 0.2 seconds. The Oklahoma bolt itself was no shrinking violet, having lasted for an impressive 5.7 seconds. Sadly, though, there's no imagery of video of either.
In any case, both lightning bolts were so prolonged that the WMO have changed their definition of what a lightning strike is. Originally, it was described as a “series of electrical processes taking place within one second,” but the last three words have now been replaced by “continuously”.
It’s not yet clear how the strike over France was able to last roughly 39 times as long as the average bolt. To be fair, it’s shocking (sorry) how much science still doesn’t know about what causes lightning in the first place. Despite there being roughly 40 to 50 lightning strikes per second on Earth, meteorologists don’t have enough data yet to truly understand these iridescent phenomena.
The path of the longest ever lightning bolt. Made using data from the research. Tom Rourke/IFLScience
“It is possible, indeed likely, that greater extremes can and have occurred,” the new report in the Bulletin of the American Meteorological Society points out. It’s all a matter of whether or not they’ve been caught on camera.
Both record-breaking flashes may have taken place in Mesoscale Convective Systems (MCSs). These are a complex of nested thunderstorms that amplify each other on a scale larger than individual thunderstorms, but not quite as much as seen within extratropical cyclones, hurricane-like swirls that take place outside the tropics. It’s possible that the most extreme lightning occurs during MCSs.