Lightning video

[wembley]

Difference between positive and negative strikes according to this guy on youtube.

https://www.youtube.com/watch?v=cbSGZGOydiA

[NZ Thunderstorm Soc]

I like "dump' thunder. Neither sounded on both the recordings.
Dump thunder sounds like a crashing sound on a long roll of thunder when it sounds as though the thunder roll has finished then you hear this boom.