“Undulatus asperatus” is a cloud formation proposed in 2009 that roughly translates to “roughened or agitated waves.” These dark and stormy clouds travel across the sky in ominous waves, but generally dissipate without an a storm forming.
Storm chaser Alex Schueth was recently in the right place at the right time with his DSLR, and managed to capture one of these formations in the mesmerizing time-lapse video seen above.
Here’s an animated GIF showing the wave-like motion of the clouds:
Schueth currently attends the University of Nebraska–Lincoln in Lincoln, Nebraska. These clouds rolled over his city on July 7th, 2014, and Schueth captured the photographs using his Canon Rebel T3i.