Only a few inches wide, a filament of current-conducting plasma known as lightning illuminates sky and earth for many miles around. High, horizontal discharges like this frequently occur in the trailing precipitation area of convective complexes. I’m loath to use the term “stratiform” for this process, as is found in many description of this area of thunderstorms, because it is convective in nature and origin. Convection causes the charge separation and buildup that leads to the lightning.
Norman OK (13 Aug 21) Looking S
35.2014, -97.4416