Wind warmed and dried by descent, in general on the lee side of a mountain. Air is forced to flow against and over a mountain range in a short period of time. The air cools as it rises up the mountain
range, cloud forms and rain or snow falls. Heat is added to the air through condensation of water vapour (latent heat) thus reducing the rate at which the air cools. When the air descends on the other side it has lost some of its moisture (because rain and/or snow has fallen from it) and it is warmed by compression as it descends. This dry, warm wind is the foehn wind. The windward side is usually very wet while the lee side can be a dry desert. Rainfall in Australia is greater in the east due to the influence of the Great Dividing Range.
Any cloudform associated with the foehn, usually referring to standing clouds of two types, orographic clouds and mountain wave clouds. Orographic clouds may include crest clouds and the foehn wall. W
ave clouds may consist of lenticular (including altocumulus standing lenticular, or ACSL) clouds, lee-wave clouds and cloud bands, and rotors. See also Bishop wave, chinook arch, contessa di vento, Moazagotl.
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). This cloud often signifies the occurrence of orographic precipitation, especially snowfall in the cold season, over the peaks. See foehn cloud.
Mountain waves, lee waves, or trapped lee waves in the air stream flowing over the mountain barrier that occur in association with foehn conditions. The Moazagotl is one example of a foehn wave made v
isible by lee-wave clouds.
The humid east wind that crosses the divide of the Andes east of Lake Titicaca and descends on the west in violent squalls; probably the same as puelche.