Is the weather forecast accurate? Said it would rain in four days.

The weather forecast in four days can only be used as a reference. Generally speaking, it will not be too accurate. It can only be said that it will rain in four days.

There are two main sources of error: one is ground variables, such as the weather will be affected by mountains and rivers on the surface, and various gases or pollution emitted by human beings every day. The other is a time variable. When these uncertain factors are constantly superimposed, they are infinitely close to the correct value in the short term. After a long time, the accuracy will drop sharply.

In the weather forecast, it is precisely because of these "variables" that it is more difficult to predict accurately, just as you can't guarantee that everything in life will happen as you expected 100%.

So we usually look at the weather forecast, which is relatively accurate within three days. If you look at the trend in a week, you will probably see it.

As we all know, there are many tornadoes in the United States, but the accuracy of tornado prediction in the United States is only 10%-20%. However, when the public receives the tornado forecast and warning, they will hide in the cellar for the first time and come out after the warning is lifted. As for whether this tornado really appears, they don't care much, because it can be delicious in the cellar.