An intense storm unfurling off the coast of Tunnel Beach, New Zealand. I don't know if a photo could do justice to just how impressive and quickly these storm clouds amassed overhead, then unleashed a torrent of rain & hail, then sped its own dark wet broodiness toward the distant horizon. You can even see plenty of blue sky adjacent to the sudden storm clouds. A time-lapse may have been more appropriate to capture the event, but I do like the challenge of trying to capture the moment into an image!
For perspective of just how gigantic this overhead storm cloud was in this 8-image panoramic, you can see a guy standing near the edge of the cliff on the right, as well as a few birds soaring way above the distant rocky outcrop.