Why is it always muggy and it doesn't rain, but the weather forecast says it will rain?

Why is it always muggy and it doesn't rain, but the weather forecast says it will rain? The weather forecast may not be accurate, but it may rain later.

Why doesn't it rain? The general process of weather forecast is to obtain all kinds of relevant data from various weather stations and observation points, and then substitute these parameters into the mathematical model designed by meteorologists, and calculate the forecast results by computer. This amount of calculation is quite huge, so it was completely impossible before the advent of computers. So whether the prediction is accurate or not depends largely on the mathematical model.

Chaos theory holds that things like weather are unpredictable (see "butterfly effect"). Therefore, the money spent on weather forecast is also a waste.

However, it is quite accurate to predict the recent weather situation in a certain area through satellite cloud images, but the specific weather or temperature in a certain place at a certain time is quite different.

Why is the weather forecast so inaccurate? Yang Guiming, a senior engineer of the Central Meteorological Observatory of China Meteorological Bureau, explained: "The accuracy of weather forecast depends on the density of observation data. However, there are only 100 sounding stations in China, which is equivalent to only one sounding station every 200 kilometers. Cloud's life is very short. A large rain cloud may rain within 10 km, but it will not be observed if the rain does not fall on the observation point. Sounding stations are sparse not only in space but also in time. Only at 8 am and 7 pm every day, the sounding balloon is raised twice for observation, and only the ground observation station is used for observation at other times. It is unpredictable that the sounding balloon rises without encountering clouds. "

"It is impossible to predict what happened a few days ago in a few hours." Yang Guiming emphasized, "An observatory is like a point in a net. The larger the network, the fewer the points, the greater the gap between points, and the higher the probability of missed detection and false detection. China has a vast territory and limited funds for meteorological observation, and it is inevitable that there will be false positives and false negatives. "

Weather forecast: prepare first, then be safe.

The weather forecast is only a probability forecast. Taking precipitation as an example, it is observed that the invasion of cold air is about to bring a rainstorm. This precipitation process can be accurately predicted, but it can only provide the probability of rainfall location. Maybe Beijing is below 80% and Tianjin is below 50%. Yang Guiming said: "At present, the accuracy rate of regional forecast of light rain and precipitation is around 50%, with the highest reaching 80% and the lowest only over 30%. The accuracy of heavy rainfall is only about 30%. However, compared with the accuracy of only 10% in the last century, great progress has been made. "

"The imagination of nature is beyond human control, and human beings can only explore and use it." Yang Guiming told reporters, "Only by understanding the weather forecast can we use it correctly. Just like earthquake warning, even if it is not accurate, you should believe it and take preventive measures. So is the weather forecast. Only when you are prepared can you be safe. "

Expert analysis: the accuracy is always greatly improved.

By 20 10, China will initially establish a comprehensive meteorological observation system, basically form a meteorological information sharing platform for the industry and the whole society, and greatly improve the accuracy of weather forecasting.

Academician Qin Dahe, director of China Meteorological Bureau, said in an interview with Xinhua News Agency that during the Eleventh Five-Year Plan period, China will also strengthen the construction of emergency system devices such as on-site comprehensive atmospheric detection, wireless information transmission, emergency meteorological information processing platform and video monitoring. Release the public meteorological forecast with a forecast period of 7 days, the quality of meteorological forecast such as typhoon and rainstorm will be improved by 5% to 10%, the deviation of typhoon track forecast in 24 hours will be within 120 km, the annual cold and warm climate forecast level of drought and flood will be improved by 5%, the accuracy of grain yield forecast will reach over 95%, and the atmospheric composition, lightning disaster and space weather forecast will be released. Establish a meteorological emergency response system for major disasters, and issue early warnings of local sudden disasters such as thunderstorms, strong winds, flash floods and mudslides more than half an hour in advance. The public coverage of meteorological forecasts and warnings is 95%.

Whether it is accurate or not, let's see.

In fact, there is a psychological reason why people have a bad impression on the weather forecast: because of the characteristics of thinking, people always firmly remember the process that brings them unpleasant experiences and ignore the process that brings them pleasure, which is the selectivity of memory.

Why does the weather forecast on QQ report rain but not rain? That's because everything is wrong. Nothing is foolproof. Things are stupid, understand!

Satisfied, please adopt.

Why doesn't it rain in Binzhou today? The weather forecast says it will rain today? Hehe, the weather forecast is sometimes inaccurate ~ I'm from Binzhou, too

Why does the weather forecast forecast rain every day, that is, it doesn't rain, and the weather forecast is updated every second? The weather forecast can't be 100% accurate, because the weather is changing at any time and the monitoring data is lagging behind. Not every second.

Why is the current weather forecast always inaccurate? Say it won't rain, say it will rain on sunny days. If people deliberately don't report, they will report that there will be no funds next year ~ and then you will know ~

Why doesn't it rain? It is not easy to see clouds in the weather forecast: the folk meteorological proverb says that "the wind jumps even if it doesn't rain" and "the dark clouds cover the sun only for three afternoons". Look at animals: dragonflies and swallows fly low, ants move, fish come to the water for air, and heavy rain is coming soon. Dragonflies go around a thousand times, and the rain will come quickly. Bees are busy picking flowers, and it will rain soon. Listen to the wind: the east wind starts at midnight.

Why doesn't it rain today? The weather forecast says rain is normal for the following reasons:

1, the weather forecast does not represent the accurate weather actual situation, after all, the forecast is not a fact;

2. Not raining is not necessarily a bad thing. The key is to adjust your mood according to the weather. Good weather means that you will be in a good mood. Why not?

I wish you happiness.

Why, today's weather forecast says it won't rain, but it does. I don't know the weather forecast here. It is raining, and the weather forecast says it will be cloudy. Small cities are not allowed, and big cities and important cities may be more accurate.

The weather forecast in Lankao is based on certain principles to infer the weather changes, but to some extent, due to various reasons, the weather is changeable and the weather forecast is inaccurate. For example:

Butterfly Effect 1960, Professor Lorenz of Massachusetts Institute of Technology studied the problem of "long-term weather forecast" and used a simplified model to simulate the evolution of weather on the computer. His original intention was to improve the accuracy of weather forecast by using the high-speed operation of computer. However, contrary to expectations, many calculations show that very small differences in initial conditions will lead to huge differences in calculation results. Lorenz used an image metaphor to express his discovery: a small butterfly flapping its wings over Brazil may cause a storm in Texas a month later-this is the famous "butterfly effect" in chaos, and children have probably heard of it. According to this theory, the accuracy of weather forecast can't be 100%.

Numerical Weather Forecast Nowadays, most weather forecasts are backed by powerful computers and complex mathematical models, instead of "seeing the weather from the clouds". Numerical weather forecast approximately represents the evolution law of the atmosphere as a set of mathematical equations. According to the initial state of the current atmosphere obtained by limited observation, the forecast of future weather or climate conditions can be obtained by solving the solutions of this set of equations. This is not an equation learned in math class. The complexity of this equation requires a supercomputer that performs hundreds of billions of operations per second to get an approximate solution. Have you found that the word "approximate" appears twice, which means that the equation and the final solution are not perfect, so sometimes there will be some errors in the final result, which is inevitable!

Have any children found that the current weather forecast has a very accurate impact on forecasting large-scale weather such as typhoons and cold air heading south, all because of meteorological satellites in the sky. The satellite images sent back by meteorological satellites every day are helpful to predict the trend of large-scale weather, but the observation range of meteorological satellites is at least as large as that of a province, and they are responsible for observing the weather in the whole country. It is impossible to keep an eye on a city all the time, so satellites can't do anything about sudden extreme weather in a small area, such as thunderstorms, thunderstorms, hail and tornadoes-which is also an important reason why sudden extreme weather in these small areas is difficult to predict.