A blizzard is not just a heavy snowfall; it is a powerful winter storm combining snow, wind, and very cold temperatures. It is one of the most serious weather events winter can bring. Knowing the difference between a regular snowstorm and an official blizzard is important for understanding the danger. A blizzard uses wind and snow to create conditions that make it almost impossible to see or travel.
The Three Criteria That Make a Blizzard Special
A winter storm must meet three specific requirements to be officially called a blizzard. The first requirement is wind, which must be sustained at a speed of 35 miles per hour or faster. This speed makes it difficult to walk or even stand up straight.
The second condition is very low visibility, which must be reduced to less than a quarter of a mile. The combination of falling snow and snow already on the ground being whipped up by the wind creates a “whiteout,” where everything looks completely white.
The third requirement is that these two conditions—the high winds and the extremely low visibility—must last for at least three hours. It does not even have to be snowing for a blizzard to happen, as strong winds can pick up snow that has already fallen, creating a dangerous “ground blizzard.”
How Blizzards Get Their Power
Blizzards are created when two very different air masses meet, fueling a powerful storm system. This requires a collision between very cold, dry air, often from arctic regions, and warm, moist air, usually moving up from the ocean. When the lighter, warm air rises over the heavier, cold air, it creates an area of low pressure.
The difference between this low-pressure area and the high-pressure air nearby generates extremely strong winds. These winds drive the moisture from the air mass upward where it freezes into snow, which is then violently blown around. These sustained, strong winds maintain the blizzard’s low visibility and power for hours on end.
Preparing and Staying Safe When a Blizzard Hits
The most important thing to do when a blizzard warning is issued is to stay indoors where it is warm and safe. Before the storm arrives, families should prepare a simple emergency kit. This kit should include:
- A flashlight.
- Extra blankets for warmth.
- A battery-powered radio for listening to weather updates.
- Non-perishable foods that do not need cooking.
If the power goes out, it is important to dress in many layers of loose clothing to trap your body heat, which is much more effective than wearing one thick layer. Never use a gas stove, oven, or outdoor grill to heat your home, as they can release dangerous, invisible fumes. Keeping the refrigerator and freezer doors closed will help keep food cold for a longer time until the electricity returns.