How Blizzards Form

Blizzards need three ingredients working together:

• Moisture — usually drawn from a nearby body of water feeding the storm
• Cold air — temperatures near or below freezing at the surface
• Lift — a front or low-pressure system forcing warm, moist air up over the cold air

The water source matters. When cold air crosses a warmer, unfrozen lake, it soaks up moisture and dumps it downwind as lake-effect snow. Buffalo, New York, can get over 2 meters from a single such event.