rotor cloud

Turbulent, altocumulus-type cloud formation found in the lee of some large mountain barriers, particularly in the Sierra Nevadas near Bishop, California; the air in the cloud rotates around an axis parallel to the range. Also known as roll cloud.

Related terms:

• foehn cloud
• cap cloud
• crest cloud
• banner cloud
• accessory cloud
• cloud base
• cloud top
• billow cloud
• cloud-to-cloud discharge
• cloud shield