What is the basis of the weather forecast?

Weather forecast is to predict the weather conditions in a certain period in the future by applying the law of atmospheric change and according to the current and recent weather situation. It is based on the analysis of satellite cloud images and weather maps, combined with meteorological data, terrain and seasonal characteristics and people's experience. For example, the satellite cloud picture of China Central Meteorological Observatory was taken by Fengyun-1 meteorological satellite made in China, and the satellite cloud picture was used for analysis. It can improve the accuracy of weather forecast, and the time limit of weather forecast is usually divided into three types: short-term weather forecast (2 ~ 3 days), medium-term weather forecast (4 ~ 9 days) and long-term weather forecast (10 ~ 15 days or more). CCTV mainly broadcasts short-term weather forecast every day.