Foehn windA foehn wind occurs when a deep layer of prevailing wind is forced over a mountain range. As the wind descends to lower levels on the leeward side of the mountains the air heats as it comes under greater atmospheric pressure creating strong gusty warm and dry winds. Foehn winds can raise temperatures as much as 30°C (50°F) in just a matter of hours.
The name "foehn" (or "föhn", pronounced as "fern") originated in the Alps. Regionally, these winds are known as "zonda winds" in Argentina, "chinook winds" in the Rocky Mountains, "Diablo winds" in the San Francisco Bay Area, "Santa Ana winds" in Southern California, and the "Nor'wester" in Christchurch, New Zealand and the Canterbury Plains.
See also: Katabatic wind.