What are the signs of heavy snow?

The sign of heavy snow is three snowflakes, as shown in the following figure:

Weather forecast means that meteorologists use modern science and technology to predict the state of the earth's atmosphere in a certain place in the future, and release the weather conditions that will appear, mainly including temperature, cloudy or sunny days, the possibility of precipitation, the intensity of precipitation, the size of wind, the visibility of air, etc. Since prehistoric times, human beings have begun to predict the weather and arrange their work and life accordingly (such as agricultural production and military operations). ). At present, the weather forecast mainly uses the collection of a large number of data (temperature, humidity, wind direction and speed, air pressure, etc. ), and then use the current understanding of atmospheric processes (meteorology) to determine future air changes. Because of the chaos of the atmospheric process and the fact that science has not fully understood the atmospheric process, there will always be some errors in the weather forecast.