CloudSpotter app user ‘wyoflower’ spotted a Cumulonimbus storm cloud wearing a combover from the window seat of a flight over Colorado, US.  

This storm’s iffy hairstyle is the accessory cloud known as pileus. This can briefly sweep over the summit of a tall convection cloud like this. The towering cloud likely encountered stable, moist crosswinds overhead. Its powerful internal updrafts will have forced the air above it to rise, causing a cloud toupee to appear over the Cumulonimbus’s summit.

Pileus accessory clouds aren’t reliable style choices. This is not because they flap up in the wind, but because they perch over clouds that are growing rapidly. In a matter of minutes, the storm cloud beneath can have grown enough to push right up through its hairpiece. Nevertheless, they’re popular for Cumulonimbus. Another storm cloud, partly out of frame at bottom right here, is wearing one also.