Which statement describes a cold front?

Which statement describes a cold front?

• A. A cold front forms when a warmer air mass slides above a colder air mass
• B. A cold front forms when a warmer air mass pushes into a cooler air mass
• C. A cold front forms when a colder air mass pushes into a warmer air mass
• D. A cold front forms when air masses mix without movement

Answer: (C)

Cold fronts happen when a colder, denser air mass advances into a region occupied by warmer air. As the cold air pushes under and lifts the warm air, it causes rapid cooling and condensation, leading to clouds and often quick, heavy precipitation. After the front passes, temperatures drop and winds can increase. On weather maps, the front is shown as a line with triangles pointing in the direction the front is moving. The other statements describe warm fronts or a stagnant boundary: a warmer air mass sliding over colder air and a warmer air mass pushing into cooler air are both characteristic of warm fronts, not cold fronts. And mixing without movement doesn’t describe a moving boundary between air masses, which is what a front is.

Cold fronts happen when a colder, denser air mass advances into a region occupied by warmer air. As the cold air pushes under and lifts the warm air, it causes rapid cooling and condensation, leading to clouds and often quick, heavy precipitation. After the front passes, temperatures drop and winds can increase. On weather maps, the front is shown as a line with triangles pointing in the direction the front is moving.

The other statements describe warm fronts or a stagnant boundary: a warmer air mass sliding over colder air and a warmer air mass pushing into cooler air are both characteristic of warm fronts, not cold fronts. And mixing without movement doesn’t describe a moving boundary between air masses, which is what a front is.