What is the sign of snow?

The sign of heavy snow is that there are three snowflakes under the cloud.

The symbol of snow is two snowflakes under the cloud.

The symbol of light snow is a cloud and a snowflake.

According to the calculation of 24-hour precipitation, the snowfall of light snow (melted into water) is 0. 1 ~ 2.4 mm, that of light snow is 1.3 ~ 3.7 mm, that of medium snow is 2.5 ~ 4.9 mm, that of medium snow is 3.8 ~ 7.4 mm, and that of heavy snow is 5.0 ~ 7.4 mm. Nine millimeters, seven. 5。

Extended data

The cause of snow

If water vapor wants to crystallize, two conditions must be met to form snowfall:

One condition is that water vapor is saturated. When saturated air is cooled to a temperature below the dew point, the excess water vapor in the air will become water droplets or ice crystals. Because the saturated water vapor content of ice surface is lower than that of water surface, the water vapor saturation required for the growth of ice crystals is lower than that of water droplets. In other words, water droplets can only grow when the relative humidity is not lower than 100%; However, when the relative humidity is less than 100%, ice crystals usually grow.

Another condition is that there must be condensation nuclei in the air. Condensation nuclei are tiny solid particles suspended in the air. The ideal condensation nucleus is the particle that absorbs the most water, such as sea salt, sulfuric acid, nitrogen and other chemicals. So sometimes there are clouds in the sky, but there is no snow. In this case, people often use artificial snowfall.