***Definition*** :: a form of mechanical turbulence that develop above and downwind of mountains > [!quote] from [[Aviation Weather Handbook]] > When the atmosphere encounters a mountainous barrier, a number of responses are possible. If the wind is weak or the moving air mass exceptionally dense, the mountains may act as a dam, preventing the motion of air over the barrier. More frequently, strong winds flow over or around mountains or ridges. If the surrounding atmosphere is unstable, the vertical displacement of the air will (if sufficient moisture is present) lead to thunderstorm formation or at least the development of deep convective clouds. However, if the wind is sufficiently strong and the surrounding atmosphere is stable, a wave will develop. ![[Mountain Wave Clouds.jpeg]] ***Source*** :: [[Aviation Weather Handbook]] ***Additional Resources***: - [The Hidden Dangers of Mountain Wave Turbulence](https://www.weather.gov/media/publications/front/11nov-front.pdf) by James Reynolds - Images from the [Sierra Wave Project](https://apps.dtic.mil/sti/pdfs/ADA511478.pdf), originally noticed in [[Weather Flying]] #glossary