Weather characteristics after cold front crossing the border

After the cold front passes, the weather is characterized by a sudden drop in temperature and humidity, an increase in air pressure, and fine weather.

The cold front is the front where the cold air mass actively moves to the warm air mass. When the cold air mass moves to the warm air mass actively, the front edge of the heavier cold air mass is inserted under the warm air mass, so that the warm air mass is forced to rise. The warm air mass cools in the process of lifting, and the water vapor in it can easily condense into clouds and rain. If the warm air contains a lot of water vapor, it may bring rain and snow.

The cold front moves faster and often brings strong winds. Therefore, when the cold front crosses the border, it is prone to rainy and windy weather. After the cold front crossed the border, the cold air mass replaced the original warm air mass, so the temperature and humidity plummeted, the air pressure rose, and the weather turned fine. Cold front exists all year round in China, especially in winter. Cold front can be divided into two types: slow cold front weather and fast cold front weather.

Frontal system

1, front

The interface between cold and warm air masses is called front. Also known as the front area, the horizontal range can be from several hundred meters to several thousand meters. Because of the high density of cold air and the low density of warm air, when the cold and warm air masses meet, the cold air mass is under the front and the warm air mass is on the front. Because there are obvious differences in temperature, humidity, air pressure and wind force on both sides of the front, there are often clouds, rain and strong winds near the front.

2. Warm front

The warm air mass climbs slowly along the cold air mass, and the water vapor cools and condenses to produce clouds and rain. Because the warm front moves slower than the cold front, it may form continuous precipitation or fog. Warm front precipitation mostly occurs before the front, mostly continuous precipitation. After the warm front crossed the border, the warm air mass occupied the position of the original cold air mass, so the temperature rose, the air pressure dropped and the weather turned fine. Warm front is active in the northeast of China and the middle and lower reaches of the Yangtze River.

3, quasi-static stop front

Quasi-static front stop means that the cold and warm air masses are evenly matched, arguing with each other and maintaining a relatively static state. This will also bring long-term continuous rainy weather ahead.