What Is A Blizzard?
QUICK ANSWER
A blizzard is a severe winter storm with three official criteria: sustained winds or frequent gusts of 35+ mph, considerable falling or blowing snow, and visibility reduced to less than ¼ mile, all lasting 3 hours or longer. Blizzards can be deadly due to whiteout conditions, hypothermia risk, and dangerous travel.
A blizzard is the most severe type of winter storm, combining heavy snow with strong winds to create dangerous whiteout conditions. The term is used loosely in everyday speech to mean any major snowstorm, but the National Weather Service has specific criteria for blizzard warnings. Understanding what officially qualifies as a blizzard, and what makes blizzards so dangerous, helps explain winter weather alerts and safety guidance.
What officially qualifies as a blizzard?
The National Weather Service defines a blizzard with three specific criteria that must all be met: sustained winds or frequent gusts of at least 35 mph, considerable falling or blowing snow that reduces visibility to less than ¼ mile, and these conditions persisting for 3 hours or longer. The snow doesn't have to be falling actively; blowing snow lifted by strong winds counts. A 'severe blizzard' has even more extreme criteria. Many storms popularly called blizzards don't actually meet the official NWS definition, even when they produce heavy snow.
What causes blizzards?
Blizzards form when intense low-pressure systems produce both heavy snow and strong winds. The pressure systems that produce blizzards often involve sharp temperature contrasts that intensify both wind and snow production. Nor'easters (storms developing along the US East Coast) are classic blizzard producers. The Plains states often see blizzards when intense low-pressure systems develop in winter and pull cold Arctic air south. The combination of strong winds (from steep pressure gradients) and heavy snow (from abundant moisture) is what makes blizzards distinct from ordinary snowstorms.
Why are blizzards dangerous?
Blizzards are dangerous for several reasons. The combination of strong winds and snow produces whiteout conditions where visibility drops to near zero, making travel impossible and causing accidents. Wind chill temperatures can drop life-threateningly low, with frostbite possible in minutes. Stranded motorists face hypothermia and asphyxiation risk if exhaust pipes get blocked by snow. Power outages from snow accumulation and wind can leave people without heat for days. The 1888 Schoolchildren's Blizzard killed 235 people on the Plains, mainly children walking home from school.
Where do blizzards typically occur?
Blizzards are most common in northern latitudes and at high altitudes where cold temperatures, abundant moisture, and intense weather systems combine. In the United States, the Great Plains, Upper Midwest, Northeast, and the Rockies see frequent blizzards. Northern Canada, Russia, Mongolia, and Scandinavia regularly experience blizzards. Antarctica has the most extreme blizzards on Earth. The southern US can occasionally see blizzard conditions during major winter storms but the criteria are rarely met simultaneously in those regions due to typically milder conditions.
What officially qualifies as a blizzard?
The National Weather Service defines a blizzard with three specific criteria that must all be met: sustained winds or frequent gusts of at least 35 mph, considerable falling or blowing snow that reduces visibility to less than ¼ mile, and these conditions persisting for 3 hours or longer. The snow doesn't have to be falling actively; blowing snow lifted by strong winds counts. A 'severe blizzard' has even more extreme criteria. Many storms popularly called blizzards don't actually meet the official NWS definition, even when they produce heavy snow.
What causes blizzards?
Blizzards form when intense low-pressure systems produce both heavy snow and strong winds. The pressure systems that produce blizzards often involve sharp temperature contrasts that intensify both wind and snow production. Nor'easters (storms developing along the US East Coast) are classic blizzard producers. The Plains states often see blizzards when intense low-pressure systems develop in winter and pull cold Arctic air south. The combination of strong winds (from steep pressure gradients) and heavy snow (from abundant moisture) is what makes blizzards distinct from ordinary snowstorms.
Why are blizzards dangerous?
Blizzards are dangerous for several reasons. The combination of strong winds and snow produces whiteout conditions where visibility drops to near zero, making travel impossible and causing accidents. Wind chill temperatures can drop life-threateningly low, with frostbite possible in minutes. Stranded motorists face hypothermia and asphyxiation risk if exhaust pipes get blocked by snow. Power outages from snow accumulation and wind can leave people without heat for days. The 1888 Schoolchildren's Blizzard killed 235 people on the Plains, mainly children walking home from school.
Where do blizzards typically occur?
Blizzards are most common in northern latitudes and at high altitudes where cold temperatures, abundant moisture, and intense weather systems combine. In the United States, the Great Plains, Upper Midwest, Northeast, and the Rockies see frequent blizzards. Northern Canada, Russia, Mongolia, and Scandinavia regularly experience blizzards. Antarctica has the most extreme blizzards on Earth. The southern US can occasionally see blizzard conditions during major winter storms but the criteria are rarely met simultaneously in those regions due to typically milder conditions.
More Severe Weather & Storms Questions
Mystery Question?
Mystery Question?
Mystery Question?