Orographic clouds
Orographic clouds appear when moisture-heavy air masses are forced by Earth’s topography (landscape) to rise over high ground, such as mountain ridges. The air moving upward over the higher ground (so called anabatic winds is cooled and the water vapour in the air mass condenses, creating clouds. Precipitation usually occurs. After crossing the higher elevation land, winds flow downhill under the force of gravity (katabatic winds) carrying high density, drier air.