Extreme lightning events set records

Two electrifying light shows were much more than flashes in the pan. A 2007 thunderstorm over Oklahoma produced a lightning flash that stretched more than 321 kilometers horizontally — roughly the distance from Washington, D.C., to New York City. In southern France in 2012, a single lightning flash lit up the sky nonstop for 7.74 seconds, enough time for light to make about three round trips from Earth to the moon.

A World Meteorological Organization committee deemed these lightning flashes the world record holders for lightning distance and duration in a paper published online September 13 in the Bulletin of the American Meteorological Society. The new records emphasize the dangers posed by lightning flashes, even when a storm appears to be far away, the committee writes.

Lightning flashes used to be defined as lasting a second or less. With improved lightning-detection techniques, however, scientists can now accurately track much longer flashes (the Oklahoma flash clocked in at 5.7 seconds), so the committee recommended dropping the time limit.

As scientists get better looks at lightning, these records may be gone in a flash. Extreme lightning has also been spotted over Argentina, Africa’s Congo Basin and the oceans.