How accurate is the weather forecast?

Do you know that many people check the weather forecast before going out? The accuracy of rainstorm forecast by the Central Meteorological Observatory is only 2 1.8%, and even the accuracy of the United States, which started earlier, is only 27%.

In our actual feeling, the accuracy of weather forecast is not so low, and it is generally felt that more than 50% of the forecast is correct. Why?

Today, the Central Meteorological Observatory revealed the secret. It turns out that the Meteorological Observatory has three kinds of statistics on rainstorm forecast:

First of all, forecast a rainstorm. This place is really raining, huh? Actually, it is a precise reward!

Secondly, we predicted that there would be a rainstorm somewhere, but it didn't rain or not so much (commonly known as empty report). Gee, the forecast is not accurate. Do you want to wash the car first?

Third, Nani? Where we didn't forecast the rainstorm, it rained cats and dogs and toppled the city. I can't hug you. Everyone who has been caught in the rain can be scolded (commonly known as omission).

When these three factors are added together as denominator, and the accurate numerator, the accuracy of rainstorm forecast can be obtained.

Taking Beijing as an example, it is predicted that there will be heavy rain in the northern areas (Yanqing, Huairou, Miyun, Pinggu and Shunyi), but only some areas in Yanqing, Miyun and Huairou will rain, and then a little rain will fall in Mentougou, Changping, accounting for almost 20% of the area. ...

People who eat melons in urban areas find it hard to understand: didn't the Meteorological Observatory say that it doesn't rain in urban areas? How can the accuracy rate be only 20%? ...

So, meteorologists, be hard on yourself!

The Central Meteorological Observatory also said: To be honest, the Meteorological Observatory is ashamed to say that its forecast is not accurate, and it is even more afraid of being shot by Keyboard Man. It is said that 2 1.8% is a little shabby and can't be taken. But be reasonable, this result is really not bad. The meteorological term must be called EC (that is, the best numerical forecasting model at present), and our accuracy is actually higher than it 10.7%. The level of science and technology in the United States is developed enough, but the accuracy of rainstorm is only 27%. Therefore, it is not enough to bring a 20% one. Let's just compare it together. Moreover, we started late, and it is not easy to catch up from more than 10%.