Altostratus undulatus
Cloud
The altostratus undulatus is a type of altostratus cloud with signature undulations within it. These undulations may be visible, but frequently they are indiscernible to the naked eye. Wikipedia
Abbreviation: As
Altitude: 2400-6100 m; (8,000-20,000 ft)
Appearance: Wavy, like ripples in a pond
Classification: Family B (Medium-level)