“Seized the moment when these fleeting Tsunami clouds rolled by last night. They are called Kelvin-Helmholtz waves and develop due to differing wind speeds in the atmosphere. Because the air is saturated at this level of the atmosphere, a cloud can form. At the top of the wave, the air is moving faster than the air at the bottom of the wave. The differing wind speed and density of the air from top to bottom is what allows the cloud to billow over like an ocean wave. They typically form either around sunrise or sunset, as the bottom layer of the cloud is cooler (more dense) than the top layer.” How cool is this?! @achunter78 got this epic shot of Kelvin-Helmholtz clouds in Virginia the other night. Her caption below explains a bit about the science behind these beauties.