Here's how it works:

* Moist Air Rises: As moist air from the ocean or other sources approaches a mountain range, it is forced to rise over the mountain.

* Cooling and Condensation: As the air rises, it cools. Cool air holds less moisture, so the water vapor condenses into clouds and precipitation falls on the windward side of the mountain (the side facing the wind).

* Dry Air Descends: The air, now dry, descends on the leeward side of the mountain (the side away from the wind). As it descends, it warms up. Warm air can hold more moisture, so it absorbs any remaining moisture from the land, creating a dry region called a rain shadow.

Examples:

* The Great Basin Desert in the western United States is in the rain shadow of the Sierra Nevada mountains.

* The Atacama Desert in Chile is one of the driest deserts in the world, located in the rain shadow of the Andes Mountains.

Let me know if you'd like more details about the rain shadow effect!