What does the probability of precipitation mean?

Precipitation probability refers to the probability of rain in a certain area today. The probability of rain is this number within the forecast time and regional scope. It can also be understood that the accuracy of this forecast in the specified time and area is this number.

The forecast published in the form of probability is called probability forecast, which originated from the United States in 1966.

Popular understanding: under certain conditions (temperature, air pressure, humidity, etc. ), the probability of precipitation in history is 30%. Knowing the forecast of precipitation probability, we can take measures against the weather that may rain to reduce the inconvenience in life.

Extended data

The general situation of precipitation probability forecast is sunny, and the probability of 0% is impossible to precipitation; Sunny to cloudy, precipitation probability 10%-20%, precipitation possibility is very small.

Cloudy, sporadic or local precipitation, when the probability is between 30% and 50%, there is a chance of precipitation; The probability of precipitation is between 60% and 70%, and the possibility of precipitation is relatively large; When the probability of precipitation is greater than or equal to 80%, the possibility of precipitation is great; If the probability of precipitation is 100%, precipitation will definitely occur.

By analyzing the data of various meteorological elements and using the principle of statistical calculation, scientists have obtained many equations for predicting precipitation probability, such as the method of predicting precipitation probability with precipitation data and the equation of predicting precipitation probability the next day with pressure, temperature and humidity of the day.

When constructing these equations, we can also use the products of numerical weather forecast. Of course, there are some more complicated forecasting methods.

Because the probability forecast only means that there is a certain possibility of a certain weather, and the probability of forecasting precipitation is 30%, when arranging activities, it is necessary to give priority to no rain and make proper preparations for rain; The probability of forecasting precipitation is 60%, and the activities are mainly rainy, supplemented by no rain; The probability of forecasting precipitation is 80%, so be prepared for rain.

Baidu encyclopedia-precipitation probability