Why is the weather forecast sometimes inaccurate?

Why is the current weather forecast inaccurate?

Zhu Qin: Will it snow tonight? Tomorrow is the last day of the New Year holiday. Whether a family can go out to play together is a problem that many people are worried about today. & ltp & gt& lt/p & gt；

Yang Hong: Do you know why everyone is unhappy? The main reason is that everyone has no idea about the accuracy of weather forecast. Is it allowed or not? & ltp & gt& lt/p & gt；

Zhu Qin: That's true. Then why is the weather forecast sometimes inaccurate, and how is it made? With these questions, reporter Xiao Ran interviewed an expert from Beijing Meteorological Observatory today. Let's listen to her report. & ltp & gt& lt/p & gt；

Xiao Ran: Hello, listeners, I'm reporter Xiao Ran. Because the weather forecast is closely related to people's lives, people can't live without it every day, especially these two days just coincide with the New Year's Day holiday. Yesterday, everyone noticed a forecast of snowy weather. It was predicted that there will be a snow tonight, and the amount of snow is even greater than that of 65438+February 3 1, and it will continue until now. At nine o'clock this morning, I interviewed Gong Xuezhong, a senior forecaster of Beijing Meteorological Observatory, about the snow. & ltp & gt& lt/p & gt；

Gong Xuezhong: Snow began to be reported a few days ago. From now on, it is hard to say whether it can arrive on schedule, because snowfall generally requires such conditions. One is that there must be a wide range of southerly airflow in North China, that is, southerly winds. After the southerly airflow is formed, it is easy to transport some warm and humid air from the south to North China, resulting in a relatively high humidity in this city. At this time, if there is cold air going south again, this kind of close combat will happen. When cold and warm weather meet, it is easy to snow, but now, this situation is not very good. A wide range of southerly winds have not been seen, but some southerly winds have appeared in some areas. Generally speaking, the southerly airflow is very weak and small, and it is uncertain whether it can develop in the future, and whether it will cause snowfall in this city. From my personal point of view, the snow may not fall, or even if it does, it will be very small, and it may be weaker than the last time. It should be said that there is a great change from the original estimate. & ltp & gt& lt/p & gt；

Xiao Ran: As the saying goes, "The weather is unpredictable", which is true. The weather forecast changes rapidly. At first I thought it was snowing heavily. After listening to what the experts said, it seems that it is not only small, but it may not stop. If someone cancels their scheduled trip tonight or tomorrow because it is going to snow, they may feel a little depressed. Further afield, it reminds us of the forecast that Typhoon Mai Sha will land in Beijing last August. Recently, it also reminds us of the snow two days ago, which is 3 1. It was originally predicted that it would snow in Beijing on the evening of the 30th, but it actually snowed in the morning of March1. Meteorologists explained that this is because the snow area is moving slower than they predicted. So how is the weather forecast made? Is it really that difficult to predict accurately? Let's listen to Gong Xuezhong, a senior forecaster and meteorologist of Beijing Meteorological Observatory. & ltp & gt& lt/p & gt；

Gong Xuezhong: There are generally two methods for weather forecast. One is the weather chart method. & ltp & gt& lt/p & gt；

Xiao Ran: The weather map, right? & ltp & gt& lt/p & gt；

Gong Xuezhong: Yes, the method of weather map is to fill in the observed weather phenomena on a blank map, and then the forecaster will analyze it. Analyze contour lines and isotherms to see where there is cold air and where there is warm air to form a weather situation, and then analyze this situation and make further predictions. There is also a numerical forecast, that is, the meteorological observation is transported to the machine, and a large number of calculations are made according to the forecast equation to get the change of the pressure field, so as to judge how the weather develops. This is the method of numerical prediction, which has really played a great role in improving the quality of prediction in recent years. & ltp & gt& lt/p & gt；

Xiao Ran: What method does our Beijing Meteorological Observatory use? Whether it is the method of meteorological map or the method of numerical prediction. & ltp & gt& lt/p & gt；

Gong Xuezhong: It is also a combination of the two. & ltp & gt& lt/p & gt；

Xiao Ran: Actually, whether based on weather map or numerical forecast, the forecaster's subjective judgment must be added. So we noticed that Gong Xuezhong used the word "I personally think" when he introduced snow to us earlier. Because the weather forecast is subjective, the Meteorological Observatory has established a daily expert consultation system to make the weather forecast more objective and accurate. & ltp & gt& lt/p & gt；

Gong Xuezhong: There are many factors that determine the weather change. It's hard to say which is the decisive factor now. Every forecaster analyzes and judges the weather situation according to his own practical experience. Because there are some gaps in understanding the weather process, there will inevitably be some differences in forecasting. If the numerical prediction is correct every time, people will naturally believe it completely. However, there is a big gap between the numerical forecast and the actual situation, so in this case, the reliability of its forecast is very great, and forecasters should make judgments. If he thinks that the situation forecast of numerical forecast may not work, then his own subjective forecast will have a greater weight, so he may have a different understanding of the forecast results. & ltp & gt& lt/p & gt；

Xiao Ran: I think that's why our Meteorological Observatory has an expert consultation system every day, which is to synthesize the opinions of various experts and ensure that the forecast can be more accurate and objective. & ltp & gt& lt/p & gt；

Gong Xuezhong: Yes, the current predictions are basically synthesized after listening to the opinions of various forecasters. Generally speaking, it is mainly based on the opinions of the majority. If the foreman forecaster thinks he is more sure, he may not follow the majority opinion. & ltp & gt& lt/p & gt；

Xiao Ran: The foreman's opinion is more important. & ltp & gt& lt/p & gt；

Gong Xuezhong: Yes, he made his judgment after carefully listening to other people's opinions. & ltp & gt& lt/p & gt；

Xiao Ran: Can you describe the atmosphere of expert consultation for us? Is it possible that everyone has different views and turns red in the debate? & ltp & gt& lt/p & gt；

Gong Xuezhong: This is indeed the case. Sometimes the weather is certain, and there may be little difference. But sometimes there are great differences, and it is common for people to be flushed. & ltp & gt& lt/p & gt；

Xiao Ran: Do our experts have great differences of opinion about this snowfall? & ltp & gt& lt/p & gt；

Gong Xuezhong: The opinion tends to be consistent, that is, this snowfall, even if it rains, it is no big deal. It's different from the original. There was a big disagreement about this two days ago. & ltp & gt& lt/p & gt；

Xiao Ran: We had a big disagreement the other day? & ltp & gt& lt/p & gt；

Gong Xuezhong: Yes, the numerical forecast at that time was a little favorable to the snowfall situation, but judging from the current development, it is developing in an unfavorable direction. & ltp & gt& lt/p & gt；

Xiao Ran: This morning 1 1, the forecaster of Beijing Meteorological Observatory held another meeting to make the forecast more accurate. After expert consultation, the final conclusion is that this snow will not come to Beijing tonight, but it will only be light snow tomorrow morning, and the snowfall will not be large and the time will not be long. & ltp & gt& lt/p & gt；

Zhu Qin: Yang Hong, do you know how some people evaluate the weather forecast? & ltp & gt& lt/p & gt；

Yang Hong: How to evaluate it? & ltp & gt& lt/p & gt；

Zhu Qin: Some people say, "To be exact, the weather forecast is sometimes inaccurate. To be fair, the weather forecast is sometimes accurate." & ltp & gt& lt/p & gt；

Yang Hong: But weather forecasting is really a limited science. We also hope that the weather forecast is accurate every day, but in fact, no country in the world can do this. & ltp & gt& lt/p & gt；

Zhu Qin: Yes, if the weather forecast is not accurate, it is related to the limitations of the weather forecast methods we have at present. & ltp & gt& lt/p & gt；

Yang Hong: And I remember when I was in Mai Sha, the staff didn't have a rest for several nights, so we can understand these accidental mistakes made by the meteorological department, because we also mentioned many reasons just now. Of course, we hope that the accuracy of future forecasts will be higher and higher. & ltp & gt& lt/p & gt；

Zhu Qin: Yes. & ltp & gt& lt/p & gt；