Why does the cold air heat up before it comes?

Because the cold air will warm up before it comes, which is closely related to the weather system. The cold air is associated with the high-altitude trough (a long and narrow area extending from the low pressure on the high-altitude weather map, the middle of which is lower than both sides, called the high-altitude trough). Because China is located in the westerly belt, the southwest airflow is often in front of the high-altitude trough, while the cold air from the northwest is behind the trough. "Warm front" refers to a short-term warming phenomenon before the arrival of cold air, which is a common weather phenomenon. This is mainly because the area before the cold front is usually controlled by the warm air mass before the arrival of cold air. As the cold front approaches, cold air quickly squeezes the previously dominant warm air mass into a narrow area to gather and heat up. In addition, the south wind usually blows before the arrival of cold air, which will also aggravate the atmospheric warming. So before the arrival of cold air, the temperature in a certain area will rise briefly (about one day). When a cold front passes, the temperature will drop. Therefore, in winter, if it suddenly warms up one day, it usually means that cold air is coming.

After the arrival of cold air, we should not only pay attention to its intensity, but also pay special attention to its residence time and moving speed, so that we can prepare for the trip.

Intensity and source. Generally speaking, weak cold air moves faster than strong cold air and cold wave, and the moving speed of cold air from different sources is also different.

Weather factors. Tropical system, subtropical high and plateau trough will all affect the speed of cold air. When the weather system in the middle and low latitudes is strong, the cold air will be blocked to the south and the speed will slow down.

Topographic factors. The sea and plain areas have small resistance and fast moving speed. Mountains have a great influence on cold air, which will slow it down and even hinder its progress. The influence of the basin on it will be more complicated.

Don't take it lightly on sunny days before and after the arrival of cold air.