Xianyang weather forecast accuracy 15 days

70% accuracy. Model weather forecast is to design a huge program to calculate weather forecast. By inputting the currently known weather phenomena, the future atmospheric motion state and weather conditions can be calculated. The change of weather is the result of the movement of the atmosphere around the earth. The basic laws of fluid mechanics and thermodynamics in physics can be used to analyze the motion of the atmosphere, and these laws can be written into mathematical equations in mathematical language. People use large computers to solve these mathematical equations, and then predict the future pressure, temperature, wind direction, wind speed and precipitation in a certain area ... Any prediction model can not completely simulate the evolution of the atmosphere, but can only be approximate, so there must be errors. Moreover, the error will accumulate, and the longer the prediction time, the greater the error.