A blizzard is defined by a specific, dangerous combination of elements. To meet the classification criteria, a storm must feature sustained winds or frequent gusts of 35 miles per hour or greater, combined with falling or blowing snow that reduces visibility to one-quarter mile or less. These conditions must persist for a minimum of three hours, establishing a weather event that makes travel nearly impossible and poses a significant risk to life and property.
Physical Damage to Buildings and Property
The weight of accumulated snow threatens private structures, particularly roofs. One cubic foot of wet snow can weigh up to 12 pounds, and this load can exceed a building’s structural capacity, leading to roof sagging or total collapse. This pressure can also cause cracks in walls and foundations, which may not become visible until after the storm has passed.
High winds accompanying the blizzard contribute to damage by transforming loose objects into hazardous projectiles. These winds can tear off shingles and flashing, leaving the underlying structure vulnerable to water penetration. Fluctuating temperatures cause accumulated snow on the roof to melt and refreeze at the edges, forming ice dams that prevent proper water drainage. This trapped water backs up beneath the shingles and seeps into interior walls, ceilings, and insulation, causing water damage inside the home.
Infrastructure and Utility Failures
Blizzards damage the interconnected systems that support daily life, making the power grid highly vulnerable. Ice accumulation and strong winds stress utility poles and power lines, causing them to snap or fall. This damage often extends to substations, resulting in widespread power outages that can leave homes and businesses without electricity and heat for days.
Communication systems also face disruption, as ice and high winds can damage cellular towers and aerial telecommunication cables. Since communication facilities rely on backup power that lasts for a limited time, power loss can lead to localized communication blackouts. Transportation networks become inoperative, with roads and railway lines impassable due to deep snowdrifts and poor visibility.
The combination of cold and prolonged utility failure threatens municipal water systems and private plumbing. When the temperature drops, water inside pipes freezes and expands, leading to cracks or bursts. This damage is often not discovered until the ice thaws, causing flooding and water damage to structures. Airport operations cease entirely due to whiteout conditions and the inability to keep runways clear, isolating affected regions.
Health and Safety Risks
The most immediate hazard blizzards pose is the threat to human health from cold exposure. Prolonged exposure to sub-freezing temperatures causes the body to lose heat faster than it can produce it, leading to hypothermia, a condition marked by confusion and slurred speech. Exposed skin is at high risk for frostbite, an injury where tissues freeze, most often affecting the fingers, toes, nose, and ears.
The struggle to stay warm during power outages introduces the risk of carbon monoxide poisoning. Improper heating methods, such as using generators, charcoal grills, or kerosene heaters indoors, release this odorless, colorless gas. Symptoms like dizziness and headache are often mistaken for the flu, requiring immediate medical attention. Additional safety risks include physical injuries from slips and falls on icy surfaces or heart strain from overexertion during snow shoveling. This surge in accidents strains emergency medical services, whose response times are hampered by impassable roads and near-zero visibility.
Agricultural and Ecosystem Losses
Farming operations suffer losses from blizzards, particularly in the livestock sector. Animals face mortality due to exposure and hypothermia, especially younger livestock with less developed heat regulation. Deep snow covers pastures and cuts off access to feed and water, often leading to starvation if alternative supplies are not available.
Perennial crops and orchards are vulnerable to deep freezes, which can destroy sensitive plants or damage the productivity of trees. Within natural ecosystems, high winds and ice accumulation damage forests, resulting in fallen trees and broken branches. This destruction disrupts wildlife habitats and affects the local ecosystem by altering the food supply for native animals.