Is the air pressure near the ground high or low before the cold front crosses the border? What are the weather characteristics? So what's it like when crossing the border? What's it like after crossin

Is the air pressure near the ground high or low before the cold front crosses the border? What are the weather characteristics? So what's it like when crossing the border? What's it like after crossing the border? Cold air is dense and easy to sink; Warm air is low in density and easy to rise. When the fast moving cold air mass rushes to the slow moving warm air mass, the heavier cold air slides under the lighter warm air, and the warm air is forced to rise, thus forming a cold front.

Warm air gradually cools as it rises. We know that warm air can hold more water than cold air. The rising warm air soon reached the dew point and formed clouds. If the warm air contains a lot of water vapor, it may rain heavily or snow heavily. If there is only a small amount of water vapor in the warm air mass, the cold front may only form cloudy weather.

The cold front moves very fast, so it will lead to sudden changes in weather, including roaring thunderstorms. After the cold front, cool and dry air moved in, so the weather was fine and the temperature dropped.