Courtney's Cloud Corner: Kelvin Helmholtz Clouds

Some clouds look like animals, where others appear like different shapes, but have you ever seen a cloud that resembles beach waves?

Kelvin Helmholtz clouds or billow clouds are not a common cloud to see, but can easily catch the eye’s attention. They appear like beach waves rolling in the sky. They get their name from William Thomson Kelvin and Hermann von Helmholtz. These scientists discovered the Kelvin-Helmholtz instability; where two parallel fluids have unstable flow because of the difference of velocities and densities. This can commonly be thought of as wind blowing over water. The Kelvin-Helmholtz instability can also be applied to shear or even temperature inversions in Kelvin Helmholtz clouds. Shear is when lower layer of air is moving at a slower speed than the upper layer of air. This will create the rolling effect in Kelvin Helmholtz clouds.

Not only does Kelvin Helmholtz clouds look magnificent, but it can also tell us of turbulence within the sky as they can be produced on a windy day.

Happen to see the rare Kelvin Helmholtz clouds or Billow Clouds? Download the Weatherology app (Google Play and Apple Store) today and share your cloud photos for us!