Related classification of weather systems

The characteristic scales of various weather systems in the atmosphere vary greatly, from tens of thousands of kilometers such as ultra-long waves and subtropical high to hundreds of meters such as tornadoes. According to the characteristic scale, it can be roughly divided into five categories, namely: planetary scale weather system, weather scale weather system, mesoscale weather system, mesoscale weather system and small scale weather system. The classification of weather systems in the world is not completely unified.

1, mesoscale weather system

In American classification and terminology, systems with horizontal scales ranging from 2000km to 2 km are collectively referred to as mesoscale weather systems, which are divided into three categories:

Mesoscale alpha weather system of 200 ~ 2000 km, including typhoons and fronts; Mesoscale β weather system of 20 ~ 200 km, including tornado and squall line; Mesoscale gamma weather system with a distance of 2-20km, including thunderstorm cell.

2. Mesoscale weather system

In Japan, the system within 2000km ~ 200km is called mesoscale weather system, and the system within 200km ~ 1km is called mesoscale weather system.

3. Large-scale weather system

In addition, there are planetary scale weather systems and weather scale weather systems collectively referred to as large-scale weather systems.

4. Sub-synoptic scale weather system

All weather systems smaller than the weather scale, including mesoscale, mesoscale and small-scale weather systems, are collectively called sub-weather scale weather systems; Some people only call a system smaller than a weather scale system (that is, a mesoscale weather system) a sub-weather scale weather system.

A more objective and unified classification of weather systems needs further study.

5, divided by the wave number

On the high-altitude weather map, the weather system is also divided according to the wave number of the whole latitude. Usually, the wave number 1 ~ 3 is called ultra-long wave, and the wave number 4 ~ 8 is called long wave, both of which belong to planetary scale weather system, and the wave number greater than 8 is called short wave, which is equivalent to weather scale weather system or smaller scale weather system.