Something on the ground was taking place. Reference post three.
I would caution folks not to see this as a massive ball in the air. It is a temporary reflection off clouds that lasted a little over five seconds.
Why did so many catch this on video? It is because the human eye could pick up a low grade reflection prior to the massive flare-up.
The brilliance of the flare-up overpowered the cameras that were set to a low light exposure, prior to the flare-up. If the sky had been lit when the videos were started, the cameras would have started off at that light intensity. Then the reflected light would have appeared much more realistically.
I suspect there was something burning on the ground. I also suspect that what we are seeing is the result of that fire causing and explosion.
I can’t say exactly what it is, but these videos are consistant with that type of activity.
A nuclear explosion would have remained brilliant for a much longer period, and those taking the video linked in post three would have been harmed.
You’ll also note no resultant nuclear wind effect. Sorry if that’s not exactly the proper terminology. Perhaps not nuclear shock wave and resultant damage would have been more accurate.
Meteor would have had similar effects, blast area, flash etc.