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A foehn wind or föhn wind occurs when a deep layer of prevailing wind is forced over a mountain range (Orographic lifting). As the wind moves upslope, it expands and cools, causing water vapor to precipitate out. This dehydrated air then passes over the crest and begins to move downslope. As the wind descends to lower levels on the leeward side of the mountains, the air temperature increases adiabatically as it comes under greater atmospheric pressure creating strong, gusty, warm and dry winds. Föhn winds can raise temperatures by as much as 30°C (54°F) in just a matter of hours. central Europe enjoys a warmer climate due to them.

Contents 1 Effects 2 Etymology 3 Local examples 4 In Popular Culture 5 Fön trademark 6 See also 7 References 7.1 Footnotes 8 External links

Winds of this type are called "snow-eaters" for their ability to make snow melt (also sublimate) rapidly. This ability is based not only on high temperature, but also the low relative humidity of the air mass.

Föhn winds are notorious among mountaineers in the Alps, especially those climbing the Eiger, for whom the winds add additional difficulty in ascending an already difficult peak.

They are also associated with the rapid spread of wildfires, making some regions which experience these winds particularly fire-prone.

These winds are often associated in popular mythology with illness ranging from migraines to psychosis. The Santa Ana winds are often called "the murder winds". A study by the Ludwig-Maximilians-Universität München found that suicide and accidents increased by 10 percent during föhn winds in Central Europe. The causation of Föhnkrankheit (English: Föhn-sickness), however, remains to be proven.

The name föhn (from the German Föhn, pronounced [føːn]) originated in the alpine region. From Latin (ventus) favonius, a mild west wind of which Favonius was the Roman personification.^[1]

Regionally, these winds are known by many different names. These include:

• Zonda winds in Argentina
• Chinook winds in the Rocky Mountains, United States/Canada and the Chugach Mountains of Alaska, United States
• Diablo winds in the San Francisco Bay Area, United States
• Santa Ana winds in Southern California, United States
• The Nor'wester in Hawkes Bay, Canterbury and Otago, New Zealand
• Halny in the Carpathian Mountains, Eastern Europe
• Fogony in the Catalan Pyrenees
• Bergwind in South Africa
• Viento Sur in the Cantabrian region (northern Spain)
• Terral in Málaga (southern Spain)
• Föhn in Austria, southern Germany and German language regions of Switzerland
• The Helm wind, on the Pennines in the Eden Valley, Cumbria, England

• Peter Camenzind, a novel by Hermann Hesse refers, at length, to the Alpine Föhn.
• The föhn plays an important part in Dario Argento's film Phenomena.

AEG registered the trademark Fön in the 1920s for its hairdryer, which is widely used as a synonym in several languages, such as German, Italian, Dutch, Romanian, Slovenian, Swedish, Turkish and French in western Switzerland.

• Katabatic winds
• Rain shadow

• McKnight, TL & Hess, Darrel (2000). Foehn/Chinoonk Winds. In , Physical Geography: A Landscape Appreciation, pp. 132. Upper Saddle River, NJ: Prentice Hall. ISBN 0130202630

1. ^ Concise Oxford Dictionary, 10th edition, Oxford University Press, entry föhn.

• Illustration