Anvil-level lightning flashes initiated by an airplane as detected by the Oklahoma Lightning Mapping Array

On 24 May 2004 the Oklahoma Lightning Mapping Array (OK-LMA) recorded four lightning flashes that were initiated by an airplane that was flying just above the anvil of a supercell thunderstorm. These flashes are unique in that they occurred where there was no natural lightning nearby and when the plane was at an altitude of approximately 12.5 km (41,000 ft). The leaders of the flashes propagated into negative charge within the anvil and positive charge above the anvil, in what was presumably screening layer charge. Radar data indicate that the flashes were initiated in a location above where the anvil was thickest and had a radar reflectivity relative maximum of 30 dBZ.