2016-8-14 - Heat lightning. If you look closely at the upper right of the bright area there are a few tendrils of electricity visible.

It was an incredible half hour show of mostly cloud to cloud lightning that flashed here, there, everywhere. It was blue. Thank you, Karen, for calling me to let me know. I'm glad to have lived to see this. Too bad I couldn't capture the impressive lightning in pictures, it was a magnificent sight!