Why is there thunder, rain and hail in the snow season?

Because the flow of hot and cold air in the sky and the change of temperature cause various climatic phenomena, rain, snow and hail are all this principle.

The water on the local surface is evaporated by sunlight and then rises into the air. A lot of water vapor condenses into clouds. The relative humidity at this time is 100%. When it meets cold air, it will liquefy, and the dust in the air will form raindrops (tropical rain) or ice crystals (mid-latitude rain), and it will become bigger and bigger. When the temperature drops to a certain extent, the water vapor in the air will be supersaturated, so it will rain.

Lightning is a discharge phenomenon in thunderstorm clouds. The formation of thunderstorm clouds should meet certain conditions, that is, there should be enough water vapor in the air, the power to make wet air rise, and the air should be able to produce strong convection. Spring and summer are affected by the warm and humid airflow in the south, with humid air and strong solar radiation. The air near the ground is constantly heated up, and the upper cold air sinks, which is easy to form strong convection, so there are many thunderstorms and even hail.

In winter, controlled by the continental cold air mass, the air is cold and dry, the solar radiation is weak, and the air is not easy to form violent convection, so thunderstorms rarely occur. But sometimes the weather is warmer in winter, and the force of warm and humid air flow is stronger. When the cold air in the north occasionally goes south, the warm and humid air is forced to rise, and the convection intensifies, so-called "thunder into winter" phenomenon will occur. Meteorologists also say that the occurrence of thunderstorms does not depend on the temperature itself, but on the upper and lower distribution of temperature.