How does the weather forecast make it possible to see the weather in advance?

The general direction of clouds and how long it will take to get there can be known by the flow of the atmosphere, and then whether there is precipitation can be predicted according to whether there is cold air in the local area.

As for predicting the temperature, a thermometer is placed in the shutter to measure the real-time temperature, and then the temperature of the day is corrected according to the local sunshine, cold and hot air flow and other climatic conditions.