These aren't your everyday fluffy cumulus clouds or storm clouds. These are gravity wave clouds -- a fascinating weather phenomenon that can form under specific conditions. Let's raise your ...

This causes the cloud to take on the shape of rolling waves. Called Kelvin Helmholtz clouds, or just wave clouds, these clouds are a sign of turbulence in the air. The cloud’s name comes from ...

Kelvin-Helmholtz instability has also been spotted on the sun and Saturn. While these wave clouds typically form in clear conditions, as Wilkie saw in Calgary, they can also form ahead of ...