gen-define-the-rain-shadow-effect-and-give-one-short-worked-exam-31de

Define the rain shadow effect and give one short worked example.

# Rain Shadow Effect ## Definition The **rain shadow effect** is a phenomenon where one side of a mountain range receives heavy precipitation while the opposite side becomes significantly drier. This occurs because mountains force moist air to rise, cool, and release moisture as precipitation on the windward side, leaving dry air to descend on the leeward side. ## Worked Example: The Cascade Range (Washington State, USA) **Setup:** - Moist Pacific air moves eastward toward the Cascade Mountains - Windward side: Western slopes facing the ocean - Leeward side: Eastern slopes facing inland **Process:** 1. **Windward side:** Moist air rises up the western slopes → cools → water vapor condenses → heavy rainfall/snowfall - Seattle (west): ~37 inches (940 mm) annual rainfall 2. **Mountain crest:** Air has lost most moisture 3. **Leeward side:** Dry air descends eastern slopes → warms → absorbs moisture → creates arid conditions - Yakima (east): ~8 inches (200 mm) annual rainfall **Result:** Western Washington is lush and forested, while eastern Washington is semi-arid shrubland—despite being only ~100 miles apart.