Why is the weather forecast sometimes invalid?

The main reason is that no matter which weather forecasting method is adopted, forecasters need to comprehensively analyze various forecasting results, which has certain limitations. In particular, many weather forecast terms are different from our usual understanding. For example, the magnitude of "light rain, moderate rain and heavy rain" in "rainfall" is strictly regulated, so sometimes people think that the rain is heavy, but in fact it does not meet the meteorological standard of heavy rain, which often leads to misunderstanding of inaccurate forecast and small rain information. At present, meteorological science is still in the development stage, the law of weather change is not fully understood, and the atmospheric movement is complex, so the current weather forecast is sometimes inaccurate.