Change is change, that is, change, indicating that the atmospheric circulation has changed and the weather system has had an impact. For example, it turns sunny to cloudy, which means that the amount of clouds in the sky is increasing.
Weather process is the process of weather phenomena changing with time in a certain area. All kinds of weather systems have certain time and space scales, and they are intertwined and influence each other.
The combination of many weather systems constitutes a large-scale weather situation and hemispheric and even global atmospheric circulation. The weather system is always in the process of rebirth, development and extinction, and there are corresponding weather phenomena in different development stages.