Why is the weather forecast always inaccurate?

? Meteorological science belongs to prediction science and has certain uncertainty. In addition, not every region has detailed monitoring stations, and the weather forecast is random. For example, in summer, strong convective weather occurs frequently, and due to factors such as topography, there is more local precipitation. At this time, the possibility of prediction error will increase.

Based on the current level of science and technology, the accuracy of weather forecast can not reach 100%, but the meteorological department will try its best to improve the accuracy of forecast.

Atmospheric movement is a very complicated process. Although the equations of numerical weather forecast can be calculated, it is difficult to truly and comprehensively reflect the laws of atmospheric motion because it abstracts the actual situation into an ideal mathematical and physical model.

Moreover, the original equations used for numerical weather forecasting can't find an analytical solution at all, but only a numerical solution (which can be understood as approximation), so there will be some errors.

In addition, the numerical weather forecast is calculated by dividing the actual space into squares, so the subtle atmospheric changes in the squares cannot be reflected, just like a mosaic will lose some information.

But god doesn't care about you. Have you ever heard of the butterfly effect? A butterfly flapping its wings can cause a tornado in the distance, so both the calculation error and the observation error will be amplified with the passage of time, leading to completely different results.