I'd appreciate it if you could help me
You probably check the weather forecast on your TV or smartphone on the day you go out. In recent years, the accuracy of weather forecasting has improved dramatically with the development of computers. However, there is a possibility that the probability of precipitation is overstated.
In the past data of precipitation, the Weather Channel in the U.S. forecasted a 20% chance of precipitation, but only 5% actually rained (*1), and in Japan, of the days when a 40% chance of precipitation was forecasted, 20% actually rained. *2
The reason is to prevent complaints. If the weather forecast says "It will rain," and you cancel your outing, but it doesn't rain, you will say "Thank goodness" or "Lucky! But if the weather forecast says it won't rain and you go out, but it rains, you will say, "What? But if you are told that it will not rain and you go out and it rains, you will say, "Oh no!
Some countries forecast a lower probability of precipitation than 50%. As an example, in Japan, when a precipitation probability of 80% is forecasted, there is almost a 100% chance of rain. They may forecast a lower probability of precipitation near 100% for fear of no rain when a 100% probability of precipitation is forecasted.
Therefore, the weather forecast may give a higher or lower probability of precipitation than what has been calculated. I understand the opinion that it is okay to heap up this much. If it is going to rain or not to rain, it may not have much effect even if the forecast is slightly exaggerated.
However, in the case of a disaster such as a typhoon, too small a forecast may cause people to delay their escape, while too large a forecast may cause people to panic, resulting in casualties. It is a difficult question whether we should say data that is really correct or data that people will not complain about.
