What is a foehn wall?
The leeward edge of the orographic stratiform cap cloud as seen from the lee side of a mountain barrier, preceding or during a foehn or chinook event. The edge is generally abrupt and resembles a wall of cloud (“foehnwand” in German).
Where do foehn winds occur?
Foehn winds are typically blown in from the Atlantic and over France or up the Mediterranean where they rise sharply over the Alps.
Which is a foehn wind?
A warm, dry and strong general wind that flows down into the valleys when stable, high pressure air is forced across and then down the lee slopes of a mountain range.
What is foehn winds helpful for?
Effects. Winds of this type are also called “snow-eaters” for their ability to make snow and ice melt or sublimate rapidly. This is a result not only of the warmth of foehn air, but also its low relative humidity. Accordingly, foehn winds are known to contribute to the disintegration of ice shelves in the polar regions …
What is foehn and Chinook?
The wind off of the Rocky Mountains in North America is a foehn wind that is called a Chinook wind. The wind is a warm, dry wind that blows down the eastern slope of most mountains. Foehn winds are formed from warmer and drier air that flows from aloft or above. This wind has the same force of some hurricane winds.
Where is foehn found?
foehn, German Föhn, warm and dry, gusty wind that periodically descends the leeward slopes of nearly all mountains and mountain ranges. The name was first applied to a wind of this kind that occurs in the Alps, where the phenomenon was first studied.
What is Foehn wind called in South Africa?
berg wind
(Literally, mountain wind.) A hot, dry, squally wind blowing off the interior plateau of South Africa, roughly at right angles to the coast; a type of foehn.
How is the foehn wind formed?
2.4 Foehn winds The winds result from the eastward flow of relatively warm, moist, unstable air along steep pressure gradients over the Rockies from the Pacific Ocean. As the air encounters the mountain barrier it converges and is forced to ascend and cool.
What is Chinook and foehn?
What do foehn winds cause?
Impacts of the foehn effect Foehn windstorms regularly cause damage to property and infrastructure, and are a serious hazard to climbers – most notoriously so on the Eiger’s north face. The combination of warm, dry air and high wind speeds promote the ignition and rapid spread of wildfires.
What is Foehn in geography?
What is lee side of mountain?
Leeward (/ˈliːwərd, ˈljuːərd/) is the direction downwind from the point of reference, i.e. along the direction towards which the wind is going. The leeward region of mountains generally remains dry as compared to the windward region. The side of a ship that is towards the leeward is its “lee side”.