As the snow piles up outside the windows, it is hard to imagine that each little snowflake is as individual as a person’s fingerprints. Snow is formed from crystals in the clouds when the temperature is beneath the freezing point. Water droplets freeze on little ice crystals. Then these crystals bump into other crystals as it falls through the clouds on its way to the ground. The unique shape of the snowflake is formed by the bumping process and the way the crystal will slightly melt and refreeze. This creates a complex design which becomes a snowflake. If the snowflake enters air that rises above freezing, it will melt into rain.
There are certain things that are true about each snowflake. Each one has six sides. Plus they can be categorized into one of six types: plate or flat; column; stars; dendrite or lacy, needle and capped column. When the temperature is extremely cold only the needle or rod shaped is produced. This creates a very fine and powdery snow. As the temperature is closer to the freezing point of 32 degrees Fahrenheit, the flakes become larger and more complex. This is when the star flake will be formed.
Not all snowflakes are white. When coal was used in homes and factories, the coal dust would enter the air and cause the snowflakes that fell to be grey in color. There has also been pink snow that has fallen. In areas that have red clay soil, the soil gets blown in to the atmosphere where the clouds absorb the soil particles. This would lead to the snowflakes that fell to be pink in color. There is a name for snow that blows off of the dusty prairies in Canada. This snow is called snirt.
The largest snowflakes on record occurred at Fort Keogh, Montana. The snowflakes were 15 inches in diameter and fell on January 28, 1887. However, Fort Keogh is not the snow capital of the world; this is Stampede Pass in Washington State. Stampede Pass averages 430 inches of snow every year.
In one snow storm billions of snowflakes fall. In order to be a blizzard, visibility needs to be down to one quarter of a mile and the winds need to be 35 miles per hour or more. The storm has to have duration of at least three hours. If any of these conditions are not met, it is not a blizzard but a snowstorm.