Blizzard
A blizzard is a severe snowstorm characterized by strong, sustained winds of at least 35 mph (56 km/h), and visibility reduced by blowing snow to less than 1/4 mile (0.4 km) for at least three hours. Here's detailed information about blizzards:
Characteristics
- Wind: Winds in a blizzard are typically sustained at speeds of 35 mph or greater, with gusts that can exceed 50 mph.
- Visibility: Blowing snow reduces visibility to near zero, making travel extremely hazardous.
- Duration: For a storm to be classified as a blizzard, these conditions must persist for at least three hours.
- Temperature: Although not a defining factor, blizzards often occur in extremely cold conditions, which can exacerbate the effects of wind chill.
Formation
Blizzards form when cold air masses from the polar regions meet warm, moist air from lower latitudes. This interaction often occurs along weather fronts. Here's how they develop:
- Moisture: A source of moisture is essential, often coming from lakes or oceans. The Great Lakes are particularly notorious for fueling lake-effect snowstorms which can turn into blizzards.
- Instability: The interaction between the cold and warm air masses creates instability, promoting the development of powerful updrafts that can carry snowflakes high into the atmosphere.
- Wind: Strong wind currents aloft and at ground level lift and transport snow, reducing visibility and creating the blizzard conditions.
Historical Blizzards
- The Great Blizzard of 1888: This blizzard struck the northeastern United States from March 11 to March 14, 1888. It paralyzed cities like New York City, Boston, and Philadelphia with up to 50 inches of snow, causing over 400 deaths.
- The Schoolhouse Blizzard of 1888: Occurring on January 12, 1888, this blizzard hit the Great Plains of the United States, resulting in many deaths, particularly among schoolchildren caught unprepared.
- The 1993 Storm of the Century: This event was not only a blizzard but also a severe winter storm that affected the entire eastern U.S. from March 12 to March 15, 1993.
Impact
- Human: Blizzards can lead to loss of life due to hypothermia, snow-related traffic accidents, and infrastructure failure. They also disrupt transportation, communication, and supply lines.
- Economic: The economic impact includes damage to buildings, loss of livestock, and disruption to commerce and daily life, costing billions in damages.
- Environmental: While blizzards can be destructive, they also have beneficial effects by replenishing the water supply through snowmelt.
Preparation and Response
- Communities prepare by stockpiling essentials, ensuring emergency services are ready, and providing shelters for those without adequate heating.
- Travel warnings are issued, and sometimes road closures occur to prevent accidents.
- After a blizzard, recovery includes clearing roads, restoring power, and assessing damage.
Sources
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