Name the warm, dry, and gusty wind that descends from the eastern slopes of the Rocky Mountains in North America.

Introduction / Context:
Local winds are an important topic in physical geography. Different regions of the world have characteristic winds with specific names, directions, and temperature patterns. On the eastern or leeward side of the Rocky Mountains in North America, a famous warm and dry wind can rapidly raise temperatures and melt snow, earning it the nickname snow eater. This question asks you to recall the standard geographical term for that wind.

Given Data / Assumptions:
• The setting is North America. • The wind descends from the eastern slopes of the Rocky Mountains. • It is described as warm, dry, and gusty. • Options list Sirocco, Loo, Chinook, Harmattan, and Mistral.

Concept / Approach:
The warm, dry wind on the leeward side of the Rocky Mountains is known as the Chinook. As moist air rises over the Rockies, it cools and loses moisture, then descends on the eastern side as a dry and significantly warmer wind. This process produces rapid warming in the plains of Canada and the United States near the Rockies. The Chinook can melt snow quickly, which is why ranchers appreciate it. Other named winds in the options are real but belong to different regions, such as Sirocco in the Mediterranean, the Loo in northern India, Harmattan in West Africa, and the Mistral in southern France.

Step-by-Step Solution:
Step 1: Identify the key phrase eastern slopes of the Rocky Mountains, which clearly indicates a North American context. Step 2: Recall from geography lessons that Chinook winds are associated with this region and are called snow eaters. Step 3: Look at the options and see that Chinook is the only North American local wind among them. Step 4: Confirm that Sirocco, Loo, Harmattan, and Mistral are each located in other parts of the world. Step 5: Choose Chinook as the correct answer.

Verification / Alternative check:
Standard geography textbooks and reliable reference sites describe Chinook as a warm, dry wind that descends the eastern slopes of the Rocky Mountains, especially in winter and early spring. They note that it can rapidly increase temperatures and melt snow, often within a few hours. These descriptions match all the cues in the question. In addition, they clearly distinguish Chinook from other named winds such as Sirocco and Harmattan, which belong to different climate zones. This confirms that Chinook is the correct name for the wind described.

Why Other Options Are Wrong:
• Sirocco is a hot, dusty wind blowing from the Sahara towards the Mediterranean region, affecting southern Europe and North Africa. • The Loo is a very hot, dry summer wind that blows over northern India and Pakistan, mainly in the Indo Gangetic plains. • Harmattan is a dry and dusty trade wind that blows from the Sahara towards the Gulf of Guinea in West Africa. • The Mistral is a cold, strong wind that blows down the Rhone valley in southern France towards the Mediterranean Sea.

Common Pitfalls:
• Remembering that Chinook is warm and thinking it must be tropical, instead of linking it to the mountain based foehn mechanism. • Confusing the Loo or Sirocco with Chinook simply because all are hot winds. • Ignoring the location clue eastern Rockies, which strongly narrows the answer to Chinook.

Final Answer:
The warm, dry, and gusty wind that descends from the eastern slopes of the Rocky Mountains in North America is called the Chinook wind.