You may know them better as “wave clouds.” Kelvin Helmholtz clouds are a common and interesting cloud formation that looks like ocean waves in the sky.
These form as wind patterns in the atmosphere interact with clouds in the sky. Wind shear is the main mechanism at play. Wind shear is created when winds at different levels are moving at a different speed in a different direction.
When the wind at the top of a cloud is moving faster than the wind at the base, it pulls the cloud top in the direction of the wind faster than the base. This causes the wave-like pattern to form and creates Kelvin Helmholtz clouds.