ROANOKE, Va. – Kelvin-Helmholtz waves are nothing new, but they might be to you. That's especially the case if you woke up Wednesday morning to see what looked like crashing ocean waves in the sky.
Kelvin-Helmholtz waves develop due to differing speeds in the atmosphere. At the top of the wave, the air is moving faster than the air at the bottom of the wave.
Because the air is saturated at this level of the atmosphere, a cloud can form. The differing wind speed from top to bottom is what allows the cloud to billow over like an ocean wave.
Chris Rupe, a teacher at William Byrd High School, captured this somewhat-rare cloud feature Wednesday morning as well.
While amazing from the ground level, these waves are a sign of turbulence in the atmosphere and can make things tricky for aviation.