At an altitude of 35,000 ft, when would a pilot most likely be in or above cloud?

• A. When the wind is from the southeast
• B. When the wind is from the northwest
• C. When the wind is from the northeast
• D. When the wind is from the southwest

Answer: (D)

When considering cloud formation, it's important to understand how wind patterns and moist air influence cloud development. In many regions, particularly in the context of weather systems and prevailing winds, winds from the southwest are often associated with the movement of moist, warm air.

As the southwest wind interacts with topography or other weather systems, it can elevate this moist air into cooler upper altitudes, which leads to condensation and cloud formation. At 35,000 feet, the air is typically cooler, and if the air is sufficiently moist enough, the chances of encountering clouds increases significantly.

Winds from other directions, such as the southeast, northwest, or northeast, may not bring the same volume or characteristics of moisture, and therefore, are less likely to lead to conditions where clouds are present at high altitudes like 35,000 feet. Hence, the southwest wind is the most likely cause of being in or above cloud at that altitude, creating an environment conducive to cloud formation due to its warm and moist characteristics.