The World Meteorological Organization (WMO) has announced a new world record for the longest-ever lightning flash.

The flash stretched more than 800 kilometres across Texas in the US, during an enormous storm in 2017.

“This new record clearly demonstrates the incredible power of the natural environment,” Randall Cerveny, rapporteur of Weather and Climate Extremes for WMO, said in a statement.

The WMO said the new record also highlighted the potential dangers that megaflashes posed for aviation and fires because of the extremely large distances they cover.

This megaflash, which occurred in October 2017, is breaking a record that was set more recently — in April 2020.

Researchers at the WMO found the flash while re-examining data from the 2017 storm.

It was also one of the first storms observed on a new satellite run by the US National Oceanic and Atmospheric Administration.