World: Longest Duration Lightning

World: Longest Distance Lightning

Record Value 17.10 ± 0.002 second
Date of Record (DMY) 06:48:58.822 UTC - 06:49:15.924 UTC on 18/6 (June) /2020
Length of Record 1/1/2018-present
Instrumentation Geostationary Lightning Mapper on Geostationary Operational Environmental Satellites (GOES-16/17)
Geospatial Location Argentina (Buenos Aires/Entre Rios Provinces) and Uruguay, Argentina [36.25°S/57.22°W to 31.68°S/58.06°W]


WMO Evaluation Panel of experts in charge of global weather and climate extremes within the WMO Commission for Climatology (CCl) consisted of the following experts: Michael J. Peterson (USA), Timothy J. Lang (USA), Timothy Logan (USA), Cheong Wee Kiong (Singapore), Morne Gijben (South Africa), Ron Holle (USA) Ivana Kolmasova (Czechia), Martino Marisaldi (Norway), Joan Montanya (Spain), Sunil D. Pawar (India), Daile Zhang (USA), Manola Brunet (Spain & UK), Randall S. Cerveny (USA).


The longest-duration flash was reported by GLM to have developed continuously over a 17.102 s period along the Argentina-Uruguay border starting at 06:48:58.822 UTC on 18 June 2020. GLM reported that the megaflash developed laterally throughout the low flash rate trailing stratiform region of an MCS. Its measured 17.102 s duration would be more than 1/3rd of a second longer than the previous flash duration record. Independent analysis by members of the WMO evaluation committee indicated a slightly longer duration of 17.2 s for the top duration case. This difference was determined to be within the expected error for the analyses, and the lower GLM-reported duration of 17.102 s was ultimately selected as the reported value.

Previous Record

16.73 seconds occurring 08:09:38.208 - 08:09:54.938 UTC 4/3 (March)/2019 in Santa Fe/Entre Rios Provinces, Argentina [43.93°N 97.12°W; to 41.02°N 96.54°W;]