Cloud Roll

Stratocumulus, Photo copyright by Craig Johnson 3-24-2020

This cloud above was one of three clouds shaped like long parallel tubes lined up in northwest to southeast oriented rows. In between the rows there were nearly cloud-free rows of blue sky. The cloud rows were caused by waves rippling through the air.

The pattern of waves is similar to waves that form on lakes and the ocean. The clouds form where the waves crest (upward motion) and disappear where air sinks (downward motion). The entire system was moving to the northeast.

Because the clouds have both cumulus (lumpy) and stratus (flat) characteristics it is called stratocumulus.

The photo below was taken looking to the northwest underneath one of the cloud rows. Sometimes the cloud rows may be much more distinct and have sharper edges.

Stratocumulus; Photo by Craig Johnson, Copyright 3-24-2020