Certified Flight Instructor - Flight Instructor Airplane Practice Exam

A moist, cold air mass being warmed from below is often characterized by which weather phenomenon?

1. Fog and drizzle.

2. Showers and thunderstorms.

3. Continuous heavy precipitation.

4. Clear and calm conditions.

The correct answer is: Showers and thunderstorms.

When a moist, cold air mass is warmed from below, it typically results in the formation of fog and drizzle. As the lower layers of the air mass warm, moisture within the air can condense, leading to reduced visibility and light precipitation, such as drizzle. This warming effect can trap moisture and reduce atmospheric instability, making it less likely for showers and thunderstorms to develop compared to a more unstable air mass. Conversely, while showers and thunderstorms occur under different conditions, they usually arise from more unstable air masses where warm air rises rapidly, leading to convection. This phenomenon is not characteristic of moist, cold air that is being warmed from below, which generally results in the more stable conditions associated with fog and steady drizzle rather than violent weather patterns like thunderstorms. In essence, the behavior of the air mass fundamentally associated with the phenomenon of warming occurring at the surface highlights why fog and drizzle are more likely and appropriate responses to the specific conditions described.