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Orographic precipitation, also known as relief precipitation, is precipitation generated by a forced upward movement of air upon encountering a physiographic upland (see anabatic windAn anabatic wind is a wind which blows up a steep slope or mountain side. These winds typically occur during the daytime in calm sunny weather. A hill or mountain top will be radiatively warmed by the Sun which in turn heats the air just above it. Air at). This upwards movement cools the air, resulting in a cloud formation and rainfall. In parts of the world subjected to relatively consistent winds (for example the trade windThe trade winds are a pattern of wind found in bands around Earth's equatorial region. The trade winds are the prevailing winds in the tropics, blowing from the high-pressure area in the horse latitudes towards the low-pressure area around the equator.s), a wetter climateThe climate is the weather averaged over a long period of time. A descriptive saying is that "climate is what you expect, weather is what you get". The IPCC glossary definition is: : Climate in a narrow sense is usually defined as the “average weather”, o prevails on the windward side of a mountain than on the leeward (downwind) side as moisture is removed by orographic precipitation, leaving drier air (see katabatic windA katabatic wind from the Greek word katabatikos meaning "going downhill", is a wind that blows down a topographic incline such as a hill, mountain, or glacier. A distinction is drawn between winds that are warmer than their surroundings (generally called) on the descending (generally warming), leeward side where a rain shadowA rain shadow (or more accurately, precipitation shadow is a dry region on the surface of the Earth that is leeward or behind a mountain with respect to the prevailing wind direction. A rain shadow area is dry because, as moist air masses rise to top a mo is formed.
Orographic precipitation is well known on oceanic islands, such as the Hawaiian IslandsThe Hawaiian Islands are an archipelago of numerous islands and atolls trending northwest by southeast in the North Pacific Ocean between latitudes 19° N and 29° N. The archipelago takes as its name that of the largest island in the group. It extends some, where much of the rainfall received on an island is on the windward side, and the leeward side tends to be quite dry, almost desert-like, by comparison. This phenomenon results in substantial local gradients of average rainfall, with coastal areas receiving on the order of 20 to 30 inches (500 to 750 mm) per year, and interior uplands receiving over 100 inches (2.5 m) per year. Leeward coastal areas are especially dry (<20 in (500 mm) per year at WaikikiWaikiki is a neighborhood of Honolulu, in the City and County of Honolulu, on the south shore of the Island of O‘ahu, Hawai‘i. The name means fetched water in Hawaiian for springs that fed wetlands that once separated Waikiki from the interior. Waikiki ha), and the tops of moderately high uplands are especially wet (~475 in (12 m) per year at Wai'ale'ale on Kaua'iKauai Kaua‘i with Okina) is the oldest and fourth largest of the main Hawaiian Islands. Known also as the "Garden Isle", Kauai lies 105 miles (170 kilometers) across the Kauai Channel, northwest of O‘ahu. Of volcanic origin, the highest point on the mount). ahaha this is so cool lol