Two record-breaking “megaflash” lightning events were recorded from space in 2020, including a lightning flash distance of 768 kilometers (477 miles) and a duration of 17.01 seconds. Such dizzying heights for lightning world-records require uniquely dramatic storms, made up of an expansive field of electrified clouds. When these conditions combine with small discharges, it can result in lightning bolts that span extraordinary distances — in this case, stretching across Texas and Mississippi.
Both records have been certified by the World Meteorological Organization (WMO). The bolt that was recorded on April 29, 2020, sets the longest-reaching lightning distance ever recorded, but that wasn’t the only trick 2020’s weather systems’ had up their sleeve. On June 18, 2020, the longest-lasting lightning bolt was recorded zapping across Uruguay and northern Argentina, lasting an incredible 17.1 seconds, topping the previous record of 16.7 seconds which also hailed from a bolt in Argentina. Details of both are published in the Bulletin of the American Meteorological Society.
Lightning records got something of a springboard in 2017 when the introduction of satellite-mounted Geostationary Lightning Mappers (GLMs) meant extreme electrical weather events across the western hemisphere could be continuously monitored for the first time. With the advantage of being stationed in space, a considerably higher vantage point than any terrestrial technologies, the GLMs enabled scientists to observe lightning bolt extent and duration across enormous expanses of land.
"Lightning is a surprisingly elusive and complex natural phenomenon for the impact that it has on our daily lives,” said lead author and evaluation committee member Michael J. Peterson, of the Space and Remote Sensing Group (ISR-2) of Los Alamos National Laboratory, USA, in a statement.
“We are now at a place where we have excellent measurements of its many facets, which allow us to discover surprising new aspects of its behavior. Now that we have a robust record of these monster flashes, we can begin to understand how they occur and appreciate the disproportionate impact that they have.”
As a result, records for distance and duration almost doubled from 2017 to 2019, when the winning zap for distance stretched 709 kilometers, but these new megaflashes top even 2019’s records.
For context, the new extent record is the equivalent distance of New York City to Columbus, Ohio in the US, or London, England, to Hamburg, Germany. For further context, 17 seconds is about this long.
“These are extraordinary records from single lightning flash events,” said Professor Randall Cerveny, rapporteur of Weather and Climate Extremes for WMO, in a statement.
“Environmental extremes are living measurements of the power of nature, as well as scientific progress in being able to make such assessments. It is likely that even greater extremes still exist, and that we will be able to observe them as lightning detection technology improves.”