The first step in the formation of any blizzard is that cold air
must be present. Warm air should start to flow over it. This first step
can occur when winds pull cold air towards the equator and away from
the North or South poles. This pulling motion will also bring warm air
in the direction of the poles and away from the equator. As the warm
air from the equator is brought into contact with the cold air from the
poles, a weather phenomenon called a "front" is formed; clouds begin to
take shape, gaining more and more moisture, which will eventually be
released as snow.
As the moisture is added to the clouds, it starts to form into water
vapor which is a mixture of gaseous water and liquid water. Generally,
blizzards that are high intensity are formed near some sort of body of
water. Bodies of water such as lakes and rivers are excellent sources
of moisture for a blizzard and can lead to some very large snowstorms.
As the blowing winds associated with a front pick up more and more
water, the storm strengthens and the blizzard becomes a much more
formidable force of nature than a simple snowstorm.
Most storms with large amounts of water built up will simply cause
torrential rainfall. A blizzard releases its moisture in the form of
snow. This is because of the third necessary requirement for a
blizzard, cold air near the ground. As the water vapor begins to clump
together to form small particles of ice, the particles begin to fall to
the ground. In a rainstorm, the ice particles will thaw and become
raindrops. In a blizzard however, because of the below freezing
temperatures near the ground, the ice will not thaw and will instead
stay frozen as they hit the ground in the form of snow, sleet, or hail.