This video is a slideshow of a series of photos I took with my drone as a storm approached Brisbane, with a strange phenomenon that I’m unfamiliar with.
You can see a horizontal bolt of lightning slowly crawling its way across the sky from left to right. What’s interesting is that each frame of the slide is an 8 second still, meaning that the bolt was visible in the sky for over a minute!
Hard to say without more info, and I don’t know if there’s more specific terminology, but yeah this isn’t impossible. You need the right conditions, like enough electric potential in the right places, and the right conditions to make it “slow” (i.e. enough potential and a difficult-to-find path) but cloud-to-cloud and intra-cloud lightning is relatively common.
What sort of additional information?