How does freezing rain form?
Rain, snow, or freezing rain are precipitation from clouds. It is the magnification of the tiny droplets or ice crystals in the clouds that cause the phenomenon of precipitation. In most cases, precipitation is formed in clouds where the temperature is low usually to form snow. This snow is composed of ice crystals, sometimes star-shaped, isolated or agglomerated into flakes whose shape depends on the temperature that prevails during their formation and growth.
When the snow crystals become heavy, they eventually fall out of the cloud and cross colder areas of the atmosphere.
If these precipitations do not cross air layers at positive temperature, they arrive on the ground in the form of snow, when temperatures are close to 0 ° C or negative.
On the contrary, when the snow arrives in areas of the atmosphere where the temperature is positive, it melts and turns into rain.
In some rare cases, the temperature decreases and freezes again near the ground. The rain or the drizzle there remain liquid by negative temperature in a particular state known as of “supercooling“. When these drops hit an obstacle they will freeze instantly, forming a compact and smooth ice deposit which we then observe as freezing rain.