Clouds over Kimberley

Coming out of the woods from a walk with the dogs I glanced up and saw this. Stopped me in my tracks, I thought- Hmm that’s impressive. Googling them I learn on a BBC iwonder site that these are called Mammatus (for obvious reasons) and says that these clouds are not clouds in their own right but an after effect of other clouds, are made up mostly of ice, and come on the back edge of a retreating storm. I just say WOW.