Kelvin Helmholtz Clouds
March 01, 2004
Boulder, Colorado, aside from enjoying wonderful views of nearby Rocky Mountains, is a great place for watching the sky and interesting cloud formations. A few times each year, Kelvin-Helmholtz clouds, like those pictured above, form during high wind events. These clouds can develop between two layers of air, having different densities, which travel at different speeds. For instance, if a warm layer exists over a layer of colder (denser) air, and the wind shear across the two layers is strong enough, eddies can form along their boundary. This results in the wavy appearance of the clouds. Such wave clouds are also known as shear-gravity waves. The above photo was taken early last month -- the wave clouds were visible for approximately 20 minutes.