Fehnfest

Fehnfest, also known as the Fehn effect, is a meteorological phenomenon that occurs in coastal regions, particularly in the northern parts of Europe. It is named after the German meteorologist Carl Fehn, who first described it in the 19th century. The Fehn effect is characterized by a significant increase in temperature and a decrease in humidity as moist, warm air from the sea is forced to rise over a coastal mountain range. This rising air cools and condenses, releasing latent heat, which warms the air as it descends on the leeward side of the mountains. This warm, dry air then flows down the mountainside, creating a foehn wind. The Fehn effect is most pronounced in the winter months, when the temperature difference between the sea and the land is greatest. It is responsible for the mild, sunny weather often experienced in coastal regions during the winter, despite the cold sea temperatures. The Fehn effect is also known to cause rapid changes in weather conditions, with temperatures sometimes rising by as much as 20 degrees Celsius in a short period.