The weather forecast is the smallest. Can you only predict in the city?
Data are data such as air pressure, temperature, precipitation, wind direction and wind force obtained by manned or unmanned weather stations, which are called live data. There won't be too many stations in a city. Meteorological scale is very large, and accurate forecast is also inaccurate and unnecessary.
Because of the large amount of data and many weather change factors, it is necessary to rely on computer calculations to carry out such calculations, such as national super-large and giant computers, which can not be counted by small computers at all; Therefore, it is impossible to accurately calculate and predict if there is too much data collection, otherwise the cost is too high; There is no end to living data and no end to calculation;
The general forecast is: according to the wind direction, look at the upstream weather to predict the downstream weather; Satellite cloud images help to see the moving speed, thickness and temperature of clouds; Numerical prediction is even more ridiculous. For example, yesterday, the day before yesterday, and the day before yesterday were rainy and sunny, then look for the data of last year, the year before last, and n years ago to calculate the probability of what the law of rainy and sunny days is.
Moreover, these forecasts are often contradictory, and need the comprehensive judgment of experienced meteorologists to give forecasts. These meteorologists can't analyze every part of the city, they can only protect the overall situation and key points. For example, during the Olympic Games, only a group of experts can make specific predictions about the venue of the opening ceremony of the Olympic Games, and other places are ignored.
These data can be queried, but it is estimated that the live data is not from the meteorological system, and it is a simplified version, which is better abroad, and there is a special meteorological website for storing big data; In addition, our country seems to keep these data secret, so as not to encounter extreme weather, for fear that you will cause panic after your own analysis and conclusion.