Lightning bolt measuring 768 km-long sets world record for longest flash

The World Meteorological Organization (WMO) confirmed on Monday, that a singular flash of lightning, which was found to be 477.2 miles (768 km) in length, has set the world record for the longest lightning flash. It was observed across Texas, Louisiana and Mississippi at 8.30am (local time) in April 2020.

It is important to note that lightning flashes are rarely over 16 km in length, and usually last for about a second.

According to AccuWeather, the south-central US "megaflash" beat the longest lightning strike record earlier held by a 708 km-long megaflash in southern Brazil (2018).

The term "megaflash" is a name given to lightning discharges that reach hundreds of kilometres in length.

A 17-second-long lightning flash across parts of Argentina and Uruguay has also set a record for the longest lightning flash (in terms of duration).

"These are extraordinary records from lightning flash events," Professor Randall Cerveny, the World Meteorological Organization's (WMO) rapporteur of weather and climate extremes, said. He also added that greater extremes are likely to exist and these may be better recorded in the future, due to advances in space-based lightning detection technology.

According to lightning specialist Ron Holle, these "extremely large and long-duration lightning events were not isolated but happened during active thunderstorms".

The WMO warns that lightning is a hazard, and urged people around the world to take caution during storms. The only lightning-safe locations are "substantial" buildings with wiring and plumbing, rather than structures such as bus stops or those found at beaches. Fully enclosed metal-topped vehicles are also considered reliably safe.

• Americas