What are the types of cold fronts?

The weather conditions of cold fronts can be roughly divided into two types: Type 1: The cold front moves slowly and has a small slope. It is in front of the 700hpa trough in the air and is usually called the first type of cold front. For this type of cold front, because the cold air mass moves forward on the one hand, the warm air mass in front of the front moves forward on the other hand, and is forced to slide upward along the front. When the water vapor conditions are sufficient, cloud systems and clouds are generated on the front. precipitation. Because this type of cold front is in front of a high-altitude trough, it is conducive to the upward movement of the air. Before the front arrives, the warm air mass is not cloudless. With the arrival of the cold front, there are often cirrus clouds and cirrostratus clouds in the air first, and the clouds follow the front. It gradually thickens as it approaches. When the front passes, it turns into nimbostratus clouds. The width of the rain area is about 150 to 200 kilometers. The second type: the cold front moves quickly, has a large slope, and is located behind or near the 700hpa trough in the high altitude. It is often called the second type of cold front. The cold advection above this type of cold front is strong, the airflow sinks, and only the warm air near the ground front is lifted. However, the front slope is large, and there is a strong upward movement of airflow. There are obvious differences in weather conditions between winter and summer. The warm air mass in summer is relatively humid and inherently unstable. Coupled with the strong cold advection above, it becomes even more unstable. Therefore, strong cumulonimbus clouds often form near the front, which are arranged near the front like a cloud embankment. When the cold front comes, thunderstorms and bursts of precipitation occur, but the rainfall area is only tens of kilometers away. In winter, the warm air in front of the front is located in front of the trough, and the airflow rises to form cirrus clouds, cirrostratus clouds, altostratus clouds, and nimbostratus clouds. There is a wide continuous precipitation area near the ground front. After the precipitation stops, strong winds often appear. People also call this kind of front a dry cold front. Because cold fronts move faster or slower, when the cold front moves slower, the warm air rises more slowly and steadily, so stratiform clouds are more likely to appear, and rainfall is also gentler; when the cold front moves faster, the warm air It will be quickly lifted by cold air, so it is often easy to create thick cumulonimbus clouds, and at the same time, there will be strong winds and rains with thunder and lightning.

Before the cold front passes: controlled by a single warm air mass, the temperature is higher, the weather is clear, and the air pressure is lower. When it passes: strong winds, cooling, and rain (precipitation is concentrated behind the front, but also in front). After the cold front passes: 1. Temperature: drops 2. Air pressure drops first Later rise 3 Precipitation: It will rain after the front 4 The weather will become sunny