Rainshadow

For the Australian television series see Rain Shadow (TV series). For the Australian Gothic Metal band, see Rainshadow. A rain shadow (or more accurately, precipitation shadow) or rainshadow is a dry region on the surface of the Earth that is leeward of or behind a mountain with respect to the prevailing wind direction. A rain shadow area is dry because, as moist air masses rise to the top of a mountain range or large mountain, the air cools and the maximum moisture content decreases until it reaches the dew point, where the water vapor condenses as rain or snow and falls on the windward side or top of the mountain. This process is called orographic precipitation. The effect of the process is the creation, on the leeward side, of an area of descending dry and warming air (see Foehn wind), and a region that is quite arid.
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