Cold air striker Wei Zi

It is a narrow and inclined transition zone between cold and warm air masses. Because there are considerable differences in temperature front and humidity between different air masses, and this difference can be extended to the whole troposphere, when two air masses with different properties meet in the process of moving, there will be an interface between them, which is called front. The line formed by the intersection of the front and the ground is called the front. Front and front are generally referred to as front. The so-called front can also be understood as the confrontation between two air masses with different properties. Because the air masses on both sides of the front are very different, the air near the front is active, the front has strong ups and downs, and the airflow is extremely unstable, which often causes bad weather changes. Therefore, the front is one of the important weather systems.

According to the classification method of thermodynamics, if a cold air mass actively pushes away a warm air mass, it is called a cold front. Otherwise, it is called warm front. If the cold air mass is equivalent, it is called a quasi-static front. If the cold front catches up with the warm front, it will form a closed front.

cold front

During the front movement, the cold air mass plays a leading role, pushing the front to move to one side of the warm air mass. This front has turned into a cold front. Cold front is often mentioned by everyone. Depth Charge, where cold air moves southward, is the most common weather system affecting China, especially in winter. In winter, a cold air invades the inland from northwest and north China every few days. When the cold front crosses the border, it will be accompanied by the increase of northerly wind, the increase of air pressure and the decrease of temperature.

warm front

Warm front refers to the front that warm air pushes the front to move towards the cold air mass during the moving process. After the warm front crossed the border, the warm air mass occupied the original position of the cold air mass. Warm fronts mostly move in the northeast of China and the middle and lower reaches of the Yangtze River, and are mostly connected with cold fronts. When the warm front crosses the border, it is warm and humid, the temperature rises, the air pressure drops, and the weather turns cloudy and rainy. Contrary to the cold front, the warm front moves slower than the cold front and may rain continuously or appear.

stationary front

When the cold air mass from the north and the warm air mass from the south are evenly matched and equal in intensity, their collision zones rarely move. This front is called the stationary front. When the cold air mass is slightly stronger, it tends to move south, and when the warm air mass is stronger, it pushes north, making the front swing from north to south, which is also called quasi-static stop front. The quiet front that affects this city often appears in spring, early summer (plum rain) and autumn, as well as in spring and autumn.