As the beautiful flakes fall to earth with each snowfall, we may notice that this snow storm is different from the last one. That is because there are differences in the molecular structure of the falling flakes. There are also differences in the way the snow falls and the characteristics of each storm have been given a specific name as well.
Some snow is made up of water vapor that has condensed and frozen into individual tiny snow crystals. These are six-sided, usually symmetrical, shapes that have formed around a particle of dust or some other impure particle that has been blown into the clouds by wind. When snow is wet and sticky the individual crystals bond together to become snowflakes and this is the fluffy type of snow that we are most familiar with.
Then there are the types of snow that aren’t as easy to identify as snow, but are considered snow. When it is foggy and cold, water vapor can condense and freeze when it lands on anything that is below freezing temperature creating a crust like surface of large snow crystals, called rime. Water that is actually in the form of drops can form hail when it freezes and when these drops form clumps they are called graupel or soft hail.
The way that snow falls to the earth has also been given a name to describe the different characteristics. There are snow flurries, which usually mean that the snow is falling so sparsely that there is hardly any accumulation if any does accumulate. The ground will look like it has been lightly dusted with powder. When the intensity of the snow fall varies over short time periods, it is called a snow shower. Intense snow showers that fall with high gusts of wind are called snow squalls, which is typical of the snow storms that come sweeping down from the north across the Great Lakes and are known as Lake Effect Snow Storms.
As snow falls it can be blown by strong winds and appear that it is snowing horizontally. The wind can also pick up snow that has already accumulated on the ground, which is known appropriately as blowing snow. When the winds reach 35 mph or more, they can blow the snow as it falls or up from the ground creating drifts (mounds) of snow. It is called a blizzard and is extremely dangerous.
Professional skiers and snowboarders are well acquainted with different types of snow since they have probably ridden almost every type. They have given names to the condition of the snow on the slopes, although some of the characteristics of the snow they describe may actually be caused by other skiers and snowboarders, not by the molecular structure of the fallen snow.
The favorite type of snow for skiers and snowboarders is aptly called powder. This is a fluffy snow that resembles powder and is almost like a pillow so when a person falls the impact is not so severe. After the snow has had many people travel over it, it becomes compacted and is called crud. Crud is uneven and lumpy with slick spots from the tracks that have been made through it. The sun will melt the top layer of snow slightly and then the snow will refreeze when the sun does not shine on it creating a crust, which is what it is called. When the temperature does not dip below the freezing point and the snow continues to melt, it becomes quite watery and is called slush.
Whatever type of snow is falling, it must be remembered that it has high water content and when it condenses into snow, it is slick and it becomes dangerous to operate a vehicle so care should be exercised. It is best to fix a cup of hot chocolate and watch the snow pile up into beautiful mountains that look like sparkling sugar.