The World Meteorological Organization (WMO) has confirmed a new record for the longest lightning flash, measuring 829 kilometers (515 miles) across the United States. This megaflash occurred on October 22, 2017, during a significant thunderstorm that extended from eastern Texas to near Kansas City, Missouri. The previous record was 768 kilometers, set in April 2020.
Advancements in satellite-based lightning detection have enabled scientists to observe such extensive lightning events. The WMO emphasizes the importance of understanding these phenomena, as lightning can travel considerable distances from its parent thunderstorm, posing potential hazards to aviation and increasing the risk of wildfires.
In addition to the distance record, the WMO has documented other lightning extremes, including the longest-duration lightning flash lasting 17.1 seconds over Uruguay and northern Argentina in June 2020. These records highlight the dynamic and powerful nature of atmospheric phenomena.
For safety during thunderstorms, the WMO advises seeking shelter in well-constructed buildings with electrical wiring and plumbing or in fully enclosed vehicles with metal roofs. Staying informed about weather conditions and adhering to safety guidelines can help mitigate the risks associated with lightning.