Foehn wind Foehn wind A föhn or foehn (, ) is a type of dry, warm, down-slope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes ("see" orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes. Föhn winds can raise temperatures by as much as 14 °C (25 °F) in just a
Significant weather advisory 58 miles per hour. The product is mainly used by forecast offices located in the National Weather Service's Southern Region Headquarters. A significant weather advisory or warning is not an official National Weather Service product, instead it is issued within a special weather statement. Special weather statements are also used for any type of weather approaching watch/warning/advisory levels. Many NWS offices do not use significant weather advisories, instead issue normal special weather statements mentioning much of the same text used in such an advisory. If severe weather is detected, alerts (mainly a severe thunderstorm or tornado warning) are issued by