[Mikejames]

is this still the case when you get lightning triggered from large amounts of smoke in wild fires? i’ve seen footage of fires in australia where the smoke becomes so big it starts to cause it’s own lightning

[jcims]

Or volcano ash: https://volcanoes.usgs.gov/volcanic_ash/lightning.html

[brendoelfrendo]

That seems to track; pyrocumulonimbus clouds happen when smoke mixes with cooler air high up. The soot and smoke could provide the nucleation sites the article talks about that promote ice crystal growth.