Look at this abnormal weather, it was 20 degrees a few days ago, and now it's 20 degrees. What's going on this time?

You see, the weather is abnormal. It was 20 degrees a few days ago, but now it's 20 degrees. The reasons are as follows: the variability of weather is the result of the interaction of cold and warm convergence, abundant water vapor, high-altitude trough and surface cyclone. Fu, an expert from the Central Meteorological Observatory, believes that large-scale heavy precipitation in the south and rain and snow in the north are the results of the simultaneous influence of warm and humid air and cold air. Take the rain in the south as an example. The warm and humid air flow from Indo-China Peninsula has brought warm spring, abundant water vapor and unstable energy to most parts of the south. The southbound cold air and warm and humid air meet and collide in the central and eastern regions of China, which brings heavy precipitation weather under the joint action of atmospheric unstable energy and other factors.