An "asperatus" cloud rolls over New Zealand's South Island in an undated picture.Yikes! Those are weird clouds. I've seen nothing like them. Before I read of the probable cause of the new clouds, I guessed.
This apparently new class of clouds is still a mystery. But experts suspect asperatus clouds' choppy undersides may be due to strong winds disturbing previously stable layers of warm and cold air.
Asperatus clouds may spur the first new classification in the World Meteorological Organization's International Cloud Atlas since the 1950s, Gavin Pretor-Pinney said.
Click the link to see more pictures of asperatus clouds in other areas.