Place the following cold front events in the correct order: As the warm, moist air ascends, cold air wedges under, cumuliform clouds form and precipitation may occur.

• A. 1, 2, 3
• B. 2, 1, 3
• C. 1, 3, 2
• D. 2, 3, 1

Answer: (A)

When a cold front approaches, the air that’s already in place (the warm, moist air) begins to rise. This lifting is the first visible effect as the front interacts with the atmosphere. As the cold, dense air moves in, it wedges under the warm air, reinforcing that upward motion. With the air continually rising, it expands and cools, leading to condensation and the development of cumuliform clouds. Those clouds can bring precipitation. So the sequence is: warm air ascends, then cold air wedges under, then cumuliform clouds form and precipitation may occur.