Why is the weather forecast inaccurate?

Seven reasons for inaccurate weather forecast

Health/2004-1112/content _ 2207888.htm.

Reason one: she is still very young.

Although the ancients had a lot of experience in forecasting weather by observing phenomena and looking for laws, the weather forecast based on modern science is only 100 years old. It was in such a simple manual workshop that she developed by simply observing the pressure field, high and low pressure, cold and warm fronts and performing simple linear calculation, while it took only several decades for numerical forecast to simplify the solution and operation of physical processes. People have not fully grasped the internal mechanisms and laws of the occurrence and evolution of many weather phenomena. Meteorological science is still the sun at seven or eight o'clock in the morning, and it is an extremely young subject. Young people always make mistakes.

Reason 2: Butterflies have countless wings.

Lorenz, a professor at MIT, used an image metaphor to express his findings: a small butterfly flapping its wings over Brazil may trigger a storm in Texas a month later. This is the famous "butterfly effect" in chaos, and it is also one of the earliest chaotic phenomena. Before our eyes, it seems that there are "countless butterfly wings" inciting. Regardless of the greenhouse effect caused by urban heat island and industrial emissions, the complex terrain of this planet has a decisive influence on the weather change, and the vegetation and water bodies are undergoing subtle changes, which cannot be described in detail in the simulation operation.

Of course, we won't be addicted to the inaccuracy of weather forecast because we have "countless butterfly wings", just as students won't lament that the exam questions are too difficult because they can't get full marks. People who often comfort themselves with "chaos" do not have the professional psychological quality of forecasting the weather.

Reason 3: Our eyes have blind spots.

To predict the weather, we must first observe the weather. Theoretically speaking, we must be meticulous and meticulous, and we must not let go of any nuance. Humans themselves have no clairvoyance and clairvoyance, but our eyes have blind spots.

Since the appearance of meteorological satellites, the blind area of our eyes has narrowed and our horizons have widened. No matter how cunning the typhoon is, it will never fool the keen eyes of the satellite. The spiral cloud type of typhoon and typhoon eye are clear at a glance, so we can safely issue those typhoon warnings. But gold alone is not enough, no one is perfect, and so are meteorological satellites. Geosynchronous meteorological satellites always pay attention to weather changes, but they are 36,000 kilometers away from the ground, with a long distance and limited resolution. Polar-orbiting meteorological satellites are more than 800 kilometers high and close to the earth, but they can't concentrate on observing a specific area. Its cloud picture is spliced. When observing a specific area, it is equivalent to the "blink" problem of satellites, and some weather happens in the blink of an eye. In addition, if there are clouds, it will be difficult for us to observe and measure the area and intensity of vegetation, water and dust. Clouds will cover up many secrets.

We don't have a pair of eyes that can see everything, so it is inevitable that there will be errors in analysis and prediction.

Reason 4: sunrise in the east and rain in the west

People often use "sunrise in the east and rain in the west" to describe the difference of weather in different places. In areas with complex terrain, or in the season of strong convective weather such as rainstorm and hail, the weather often varies greatly in a small area.

A mountain, windward slope and leeward slope, the temperature and precipitation are very different, so the vegetation looks very different. Just across a mountain, there are two types of climate. The ancients said: when you first realized that there was a ridge between you, the climate was very cold.

However, China has a vast territory, which is influenced by both the continental weather system at middle and high latitudes and the maritime weather system at low latitudes. There are many kinds of meteorological disasters, and it is one of the countries with the largest and most serious types of meteorological disasters in the world. We can only describe a wide range of features in a minute or two "from the overall situation", which will certainly delete many local weather phenomena, omit many weather plots, and cannot express such complicated weather changes.

Reason 5: Misdiagnosis of Difficult Diseases

There are many kinds of diseases and the difficulty of diagnosis and treatment is different. No matter how skilled a doctor is, he will sometimes be misdiagnosed, and he will often encounter intractable diseases for taking the pulse of the weather.

I clearly remember an example: as soon as the typhoon was generated, it stormed the southeast coast and we issued an alarm. However, the typhoon strangely stopped moving and rested in place. But just when people breathed a little sigh of relief, it killed another comeback and re-aimed at the southeast coast, so we issued a typhoon warning again. However, when the alarm sounded, the typhoon swaggered towards the Pacific Ocean. In the end, the typhoon surprised people. Afterwards, several colleagues concluded that the typhoon seemed to be specially used to tease us.

A normal weather process, even if it is not predicted (in jargon, it is empty), often occurs without prediction (in jargon, it is missing). For a long time, in order to reduce the negative social impact, some people in the industry have the mentality of "rather empty than leaking". Aside from the forecasting mentality in the industry, I personally feel that it is precisely because of many extremely difficult forecasts, especially the omission, that people (including leaders) lack fair evaluation of mistakes, and many colleagues engaged in forecasting are often treading on thin ice. One of my leaders has a saying on his lips: Ten thousand years later, people will still talk about the accuracy of the weather forecast. The weather forecast is always inaccurate. I hope he can give the audience an injection after 10 thousand years. The problem of weather forecast will persist for a long time. It is really very difficult to find out God's temper.

Reason 6: Your feelings deceive yourself.

In the spring of 2004, an intern said to me: What will you do in summer? This sentence makes me puzzled. He explained: Everyone says that the high temperature season is obviously more than 40 degrees, but you always report the appearance of 36 degrees and 37 degrees, for fear of causing panic, so you dare not report it and are unwilling to report the high temperature.

After listening to this analysis, I really feel wronged!

In the summer of 2003, there was a long and large area of high temperature weather in the south, and the shortage of water and electricity was very prominent. Shanghai's night lighting has also taken restrictive measures. In Fujian, Jiangxi and Zhejiang, the temperature in many areas is like a sports competition. The temperature has been refreshed repeatedly, and the major "stoves" complement each other. As a result, many viewers reported that the weather forecast deliberately lowered the temperature, concealed it, and even rose to the political height of "depriving people of the right to know".

But in fact, for the high temperature weather in the summer of 2003, the meteorological department only made a very wonderful and conclusive forecast. Only the Central Meteorological Observatory issued 3 1 high temperature forecast and early warning at the first time, and the temperature forecast error was generally around one degree or even lower. However, why is there such a strong contrast between wonderful science and the public?

Tracing back to the source, the difference between temperature and human somatosensory (somatosensory temperature) is the primary cause of complaints and doubts.

When we say temperature, we mean the temperature in the blinds. On the lawn, off the ground 1.5 meters, ventilated, without direct sunlight. But our somatosensory temperature is influenced by many factors. The same temperature, in the sun and under the shade, feels very different; There is a great difference between windy and windless; Dry and wet, there is a big difference, and the difference in feeling is generally above 5 degrees. And in the scorching sun, the ground temperature is much higher than the air temperature. When the temperature is 35 degrees, the surface soil temperature may be 50 degrees, and the temperature of cement or asphalt pavement may be 70 ~ 80 degrees, so when you walk on the road, you feel that the temperature is far more than 35 degrees, so you have doubts about the weather forecast.

In fact, in the history of weather forecast, there has never been a subjective and intentional depression of the temperature forecast results in midsummer season. If there is such a thing, it is a despicable act that completely hurts professional ethics, and we cannot tolerate it!

Reason 7: Lack of inaccurate summary.

I have read many articles and summaries about how wonderful the prediction is and how successful the analysis is, but I seldom see the analysis and comments on the cases of failure in prediction. It seems that some people don't want to touch scars, and they haven't sincerely discussed the professional atmosphere of failure. Once there is an important error in the forecast, the atmosphere will become very dignified and afraid to mention it, for fear of hurting someone's feelings.

At the end of the weather forecast of Beijing TV Station, there is a screen called "Satisfaction rate of weather forecast on a certain day of a month", and the audience scores the daily weather forecast results. I will read this information carefully every time, which is an important channel to understand the audience's attitude towards the quality of forecast. The satisfaction rate is often very high, 90% or even 100%. However, there are also times when the satisfaction rate is very low. For example, it is predicted that there will be "light rain" in Beijing on June 14 and June 15, 2004, but God just doesn't want to cooperate. On June 14, there was strong wind and sand blowing. On June 15, it didn't rain, although the sky was cloudy and cloudy. I passed a swimming pool that day. Of course, everyone in the industry knows that the prediction in that year was indeed very difficult. /kloc-June 0/6, it seems that God was finally moved by persistent prediction. It rained all day, but the predicted maximum temperature was 24 degrees, while the actual temperature in the afternoon was only 17 degrees. People wearing thin clothes shivered with cold and complained bitterly, but the forecast satisfaction rate on June 15 was 865438+.