Which of the following describes the weather characteristics of a cold front?

A cold front is characterized by the rapid movement of cold air replacing warmer air. This scenario typically leads to a swift drop in temperature as the cold front advances. As the warm air is forced to rise abruptly over the denser cold air, it can lead to significant weather phenomena, such as thunderstorms, due to the instability caused by the varying temperatures and pressures.

Thunderstorms associated with cold fronts can be intense and often come with strong winds, heavy rain, and occasionally hail. The passage of a cold front is usually marked by a sudden change in wind direction and an increase in atmospheric pressure once the front has passed.

The other choices describe different weather phenomena that do not align with the cold front characteristics. Gentle rain over long periods is typical of warm fronts, and consistent warm, dry conditions are more indicative of high-pressure areas, while mixed fog and overcast skies could be associated with warm fronts or stationary fronts rather than a cold front.