VIDEO: What conditions create a blizzard?

PHILADELPHIA (WPVI) -- What exactly are the conditions necessary for a blizzard to be declared?

According to the National Weather Service, there are three:

1 - Winds gusting in excess of 35 m.p.h.

2 - Snowfall which reduces visibility to 1/4 mile or less

3 - The storm lasting 3 hours or longer

The Delaware and Lehigh Valleys have experienced blizzards before. Most recently, we experienced two in the same winter, back in 2010.

The first occurred on February 5, 2010.

Scenes from the Blizzard of 2010.

The second, just a few days later on February 9.

Scenes of from the Blizzard of 2010.