Lee Waves are atmospheric phenomena that occur when stable air flows over a mountain range or hill. As the air rises over the peak, it cools and can create a series of waves on the downwind side. These waves can lead to the formation of clouds and turbulence. The waves are named after Benjamin Lee, who studied their effects. They can extend for many miles and may influence weather patterns in the surrounding areas. Pilots often need to be aware of Lee Waves as they can create challenging flying conditions, especially in mountainous regions.