What is the cause?

Blizzards occur when cold masses of air move out of the Arctic into the Temperature Zone.  Advancing heavily, cold air forces the warmer, moist air to rise up along the boundary between the two air masses.  That boundary is called a cold front.  Action rise produces a heavy snowstorm with cold, northern winds.  Still, this is very dangerous.

This is the result of the cause, the effect, which is a blizzard.