Blizzards are severe storms which are marked by extremely low temperatures, high-speed winds and substantial snowfall. They are formed when a region of high atmospheric pressure, termed as a ridge, interacts with a region of low atmospheric pressure.

As a result of this, a phenomenon known as advection takes place, in which there is a rush of air from the high pressure region to the low pressure region. The visibility is reduced to less than a quarter of a mile.

Three factors necessary for blizzards to form

  1. Air below freezing point (typically 20 degrees F and below) that can cause snow, should be present both at the heights of the clouds and near the ground. As a result, snow is formed at the clouds, and near the ground, the snow is prevented from melting.
  2. There should be adequate moisture to help clouds develop, and result in precipitation. Wind blowing over a lake is a sure source of moisture.
  3. Warm air that rises over cold air should be present for the blizzard to develop, resulting in strong winds at more 35 miles per hour.

How Blizzards Form