What are the signs of heavy snow, medium snow and light snow?

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

The symbol of snow is two snowflakes under a cloud.

The symbol of light snow is clouds and snowflakes.

Based on the 24-hour precipitation, the snowfall (melting into water) is 0. 1 ~ 2.4 mm, small to medium snow 1.3 ~ 3.7 mm, medium snow 2.5 ~ 4.9 mm, moderate to heavy snow 3.8 ~ 7.4 mm, and heavy snow reaches 5.0 ~ 9.9 mm and 7.5.

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 becomes 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. That is to say, water droplets can only grow when the relative humidity is not lower than 100%; But when the relative humidity is less than 100%, ice crystals tend to 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.