In March 1888, areas in the northeast received up to 55 inches of snow for several days. On February 5, 1978, Boston and Providence were met 27 inches of snow, hurricane force winds and coastal flooding. In December 2022, Buffalo received over 55 inches of snow due to a blizzard nearly 60 percent of Americans.
Since they have been recorded, blizzards have affected the United States. As they continue to make an impact, scientists have learned more about how these dangerous winter storms form.
What is Blizzard?
It may seem like every winter storm that dumps us with snow is called a blizzard, but the requirements to classify a storm as a “blizzard” are unique.
A blizzard is any winter storm that lasts at least three hours with large amounts of snow (or sleet), has winds of at least 35 miles per hour, and has visibility of less than a quarter mile, according to National Weather Service.
If a storm does not meet these conditions, it is not classified as a blizzard. But even if a winter storm isn’t labeled as a blizzard, it can still create blizzard conditions. Winter storms can produce snow and high winds for short periods of time, but not long enough to be considered a blizzard.
Additionally, forecasters will declare winter storm blizzard conditions if visibility is reduced by snow to less than a quarter mile, according to National Geographic.
How blizzards form
According to University Corporation for Atmospheric Researchthere are three conditions necessary for a major snowstorm or blizzard to occur.
First, subzero air is required for snow to form. The air must be below freezing both at ground level and in the clouds. If the air is too warm near the ground, the snow will melt into rain or sleet.
Second, a blizzard needs moisture, which is necessary for cloud formation and ultimately precipitation. Moisture is key lake effect snow and Nor’Easters. These types of storms, which are classified as blizzards, rely heavily on wind to blow into bodies of water and pick up moisture along the way.
Finally, the moist air must rise above the cold air to form a blizzard. This can be done in two ways. If the wind simultaneously pulls warm, moist air up from the equator and cool air down from the North Pole, the moist air will rise above the cold air, creating a front. A front can also form if warm air rises up a mountainside to sit on top of cold air.
When a storm system forms, blizzard conditions usually accumulate on its northwest side, due in part to cold air blowing in from the northwest. Meanwhile, blizzard winds are picking up because of the storm’s low pressure. Beyond the storm, the air pressure is higher, causing the winds inside to accelerate.
In general, blizzards are powerful, dangerous storms that require the right conditions to form. Their strong winds, freezing temperatures and white snow make travel almost impossible. If you find yourself in the path of a blizzard, it’s best to duck until the storm passes.