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.
Asperatus’s champion, Gavin Pretor-Pinney, author of The Cloud Collector’s Handbook, argues for greater appreciation of his subject.
“Even if you live in the middle of the city,” he said, “the sky is the last wilderness you can look out on.”