Clouds crashing in the sky Sep 26 2014
There's an incredible 16-second sequence in this video of clouds, starting at around 10 seconds in. It looks as though the sky is a roiling ocean wave about to crash on the beach. I've watched it approximately 90 times so far today.
It's worth making the video fullscreen and pumping it up to the max quality (2160p!) to see it properly. (via colossal)