Cause of formation of cold vortex at high altitude

Generally speaking, there are two reasons for the low pressure of cold nuclei at high altitude. One is that the mid-latitude trough is cut off after the amplitude increases, and the other is the easterly fluctuation in the upper air south of the upper anticyclone. As far as the circulation structure is concerned, the circulation characteristics of cold core low pressure will gradually weaken with the decrease of height. Therefore, the system is not easy to appear on the ground weather map, and its pressure field cannot be seen below 700 hectopascals. It is usually necessary to judge the movement and development of satellite images by animation tracking.

The low pressure and cold center features of 100hPa, 200hPa or 300hPa high altitude weather maps will be represented by L and C, and the cyclone rotation of high altitude water vapor can be seen in the water vapor animation.

After the system is generated, it will generally move westward along the edge of tropical high. When this cold core passes through low pressure, the temperature in the upper air becomes cold, which increases the unstable conditions of the atmospheric environment and is easy to promote the development of convection.