https://earthsky.org/earth/megaflash-lightning-record-us-texas-kansas-city/
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The GOES-16 satellite monitored the megaflash, which stretched from East Texas to Kansas City...
There is a margin of error of plus or minus 5 miles (8 km) in the new record of 515 miles (829 km). It is 40 miles (61 km) greater than the previous record..."