Rain shadow .. what is this phenomenon and how does it occur?

Written By وداد السعودي on 2020/09/21

This article was written originally in Arabic and is translated using a 3rd party automated service. ArabiaWeather is not responsible for any grammatical errors whatsoever.

ArabiaWeather - the phenomenon of rain shadow, what is it and how does it occur?

What is the rain shadow phenomenon?

The "Rain Shadow" phenomenon is known to occur when the mountains intercept the humid winds, forcing them to ascend towards their slopes, and the air cools and the humidity condenses and the rain falls on the opposite side of the winds, and when these winds descend on the opposite side of the mountains, the clouds disappear due to the falling winds , So that the other side falls under the influence of the so-called rain shadow phenomenon.

An illustration of the rain shadow phenomenon

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The areas affected by the rain shadow phenomenon suffer from high temperatures; Due to the movement of the downward winds that heats themselves, the lack of humidity is a contributing factor to the high temperature at noon and its rapid decline at night.
It is also noted that the vegetation cover that is directly opposite to the humid winds is dense greenery and full of trees, while the other side in the opposite direction suffers from a lack of vegetation cover and possibly desertification.

Examples of places where the rain phenomenon occurs:

There are many examples of Arab cities that occur that stimulate the effect of the rain shadow phenomenon, the most important of which is: the Jordanian capital, Amman, where the amount of rain in the western parts of it (corresponding to the humid western winds coming from the Mediterranean) reaches more than 500 mm and the temperatures are moderate, while The eastern side, opposite to the direction of the winds, has a rainfall of less than 250 mm and temperatures are less moderate.

The mountains of Lebanon are among the most prominent examples of the phenomenon of rain shadow, as the western part of the Lebanon Mountains is covered with dense forests, but the eastern part of it has little vegetation.

The southwestern Saudi highlands are also included in the impact of this phenomenon, such as the Al-Souda region, Al-Baha, western Asir and the Fifa Mountains, where heavy rains abound, while the eastern parts of them, such as Najran and Bisha, are affected by less rain and a drier atmosphere.

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