Private Pilot Private Exam

Which characteristic is associated with stable air?

1. Thunderstorm development

2. Stratiform clouds

3. Vertical wind shear

4. Cumulonimbus clouds

The correct answer is: Stratiform clouds

Stable air is characterized by a limited vertical movement of air, which results in the formation of stratiform clouds. Stratiform clouds typically appear as uniform layers and are associated with gentle, widespread precipitation. In a stable atmosphere, the air is resistant to rising, leading to a more horizontal cloud formation rather than turbulence. On the other hand, thunderstorms, vertical wind shear, and cumulonimbus clouds are generally associated with unstable air. Thunderstorms, for instance, require rising air currents to develop, while vertical wind shear indicates a change in wind speed or direction with altitude, which can result in turbulence and instability. Cumulonimbus clouds are towering clouds formed in unstable conditions, leading to severe weather phenomena. The presence of stratiform clouds is a clear indicator of stability in the atmospheric conditions.