Use pictures or words to express how snowy weather is formed.

Snow is divided into light snow, moderate snow and heavy snow. The illustrations and text are as follows

The water vapor in the air encounters some tiny floating dust in the sky, and then begins to condense. Under specific temperature conditions, crystallization begins to grow and form snowflakes. When its weight increases to a certain level, it begins to decrease and form snowfall; if the temperature continues to decrease, hail may form, and if the temperature rises, rain will form.