Snow is what is called frozen water that has precipitated. It is nothing more than water in a solid state that falls directly from the clouds. Snowflakes are made up of ice crystals that, as they descend to the earth's surface, cover everything with a beautiful white blanket.
If you want to know how snow is formed, why it snows, the types of snow that exist and its cycle, keep reading 
Generalities
Snowfall is known as a snowstorm . This phenomenon is common in many regions characterized by low temperatures (usually during winter). Heavy snowfall often damages urban infrastructure and disrupts daily and industrial activities.
The structure of snowflakes is fractal . Fractals are geometric shapes that repeat themselves at different scales, creating a very curious visual effect.
Many cities have snow as their main tourist attraction (for example, Sierra Nevada). Thanks to the heavy snowfalls in these places, you can practice different sports such as skiing or snowboarding. In addition, the snow offers dreamlike landscapes, capable of attracting many tourists and generating great profits.
How is it formed?
We have talked about how snow is a strong tourist attraction and that it leaves beautiful landscapes in its wake. But how do these flakes form?
Snow consists of small crystals of frozen water that form in the upper troposphere through the absorption of water droplets. As these droplets collide, they merge to form snowflakes. When a snowflake's weight exceeds the resistance of the air, it falls.
For this to happen, the snowflake formation temperatures have to be below zero. The formation process is the same as with snow or hail. Only the difference between them is the formation temperature.
When snow falls to the ground, it accumulates and forms layers. As long as the ambient temperature remains below freezing, it will persist and continue to accumulate. If the temperature rises, the snowflakes will begin to melt. The temperature at which snowflakes typically form is -5°C . They can form at slightly higher temperatures, but it is more common below -5°C.
People generally associate snow with extreme cold, when in reality most snowfall occurs when the ground temperature is 9°C or higher. This is because a crucial factor is often overlooked: humidity. Humidity is the determining factor in whether snow forms in a given location . If the climate is very dry, there will be no snowfall even with very low temperatures. The Dry Valleys of Antarctica are a prime example, where there is ice but never snow.
There are times when the snow dries up. It is about those moments in which the flakes, formed with the humidity of the environment, pass through a mass of dry air that turns them into a kind of powder that does not stick anywhere and that is ideal for those snow sports.
The accumulated snow after a snowfall has different aspects depending on how the meteorological actions develop. If there are strong winds, melting snow, etc.
Snowflake shapes
The flakes usually measure little more than one centimeter, although the sizes and compositions depend on the type of snow and the air temperature.
Ice crystals come in countless shapes: prisms, hexagonal plates, or the familiar star shapes . This makes each snowflake unique, even though they all have six sides. The lower the temperature, the simpler and smaller the snowflake.
Types of snow
There are different types of snow depending on the way it falls or is generated and the way it is stored.
Frost
This is a type of snow that forms directly on the ground. When temperatures are below freezing and humidity is high, the water on the Earth's surface freezes, creating frost. This water accumulates mainly on windward sides and is able to transfer moisture to plants and rocks on the ground.
Large feathery flakes or solid encrustations may form.
Icy frost
The difference between this frost and the previous one is that this snow does form defined crystalline shapes, such as sword-like leaves, scrolls, and calyxes. Its formation process is different from conventional frost. It forms through sublimation.
Powder snow
This type of snow is the most common, known for being fluffy and light . It is snow that has lost its cohesion due to temperature differences between the edges and center of the ice crystals. This snow allows for good skiing.
Grainy snow
This snow is formed by the continuous cycle of thawing and refreezing suffered by areas where the temperature is low but there is sun. The snow has thick and rounded crystals.
Lost snow
This type of snow is more common in spring. It consists of soft, wet layers that lack resistance. It can cause wet snow avalanches or slab avalanches. It is usually found in areas with lower precipitation.
Crusted snow
This type is formed when surface melt water refreezes and forms a firm layer. The conditions that give rise to the formation of this snow are the warm air, the superficial condensation of the water, the incidence of the sun and the rain.
Normally, the layer that forms is thin and breaks up when skis or boots pass over it. However, there are situations where a thick, crusty layer forms when it rains and the water seeps through the snow and freezes. This crust is much more dangerous because of how slippery it is. This type of snow is more common in rainy areas and seasons.
Wind plates
The wind gradually ages, breaks down, compacts, and consolidates all the surface layers of the snow. Consolidation occurs more readily when the wind carries more heat. Even if the heat from the wind isn't enough to melt the snow, it is capable of hardening it through transformation. These wind slabs that form can break if the underlying layers are weak. It is then that an avalanche occurs.
firnspiegel
This name is given to the thin, transparent layer of ice found on many snowy surfaces. This ice reflects sunlight. This layer forms when the sun melts the surface snow, which then refreezes. This thin layer of ice creates a mini-greenhouse effect , causing the underlying layers to melt.
verglas
It is a thin layer of transparent ice that is produced when water freezes on top of a rock. The ice that forms is very slippery and makes an ascent very dangerous.
Fusion gaps
They are cavities that form due to the melting of snow in some areas and can reach highly variable depths. At the edges of each hole, the water molecules evaporate and in the center of the hole, the water is trapped. This forms a liquid layer which, in turn, causes more snow to melt.
Penitentes
These formations occur when fusion cavities grow large. Penitentes are pillars formed by the intersection of several cavities. Columns form, resembling penitents. They are found in large areas with high altitudes and low latitudes. Penitentes are most developed in the Andes and Himalayas, where they can measure over a meter in height, making walking difficult. The columns often lean towards the midday sun.
Drainage channels
It forms when the thaw begins. Drainage networks are created by water runoff. The actual water flow doesn't occur on the surface, but rather within the snowpack . The water seeps through the ice layer and eventually reaches the drainage networks.
Drainage channels can cause avalanches and make skiing difficult.
Dunas
The dunes are formed by the action of the wind on the snowy surface. The dry snow takes erosive forms with small waves and irregularities.
Cornices
They are accumulations of snow on the ridges that constitute a special risk, since they hang forming an unstable mass that can be detached by the passage of people or by natural causes (strong wind, for example). It is capable of forming avalanches, although its danger is present just by falling by itself.
With this information you will surely be able to know the snow much more thoroughly and recognize the type of snow that is there at that moment the next time you go to a snowy place.
