Why in news?
Winter storms in North America and Europe frequently make headlines, and the term “blizzard” is often used in weather forecasts. While India rarely experiences blizzards, the phenomenon is important for geography and disaster management topics.
What is a blizzard?
A blizzard is a severe snowstorm characterised by strong winds and very low visibility. The United States National Weather Service defines a blizzard as a snow or blowing‑snow event with sustained winds of at least 35 miles per hour (about 56 km/h) and visibility reduced to a quarter mile (about 400 metres) or less for three hours or more. Heavy snow may already be on the ground; the key elements are wind and visibility.
How blizzards form
- Pressure systems: Most blizzards develop on the cold, north‑western side of a strong low‑pressure system. Warm moist air from the south clashes with cold air from the north, creating precipitation.
- Wind: Tight pressure gradients cause powerful winds that pick up snow from the ground and blow it around, creating whiteout conditions.
- Temperature: Sub‑zero temperatures allow snow to accumulate rather than melt. Wind chill can make it feel much colder.
Impacts
- Travel disruptions: Accumulating snow and poor visibility make roads dangerous. Airports and railways may shut down.
- Power outages: Strong winds topple trees and power lines, cutting electricity and heating during cold spells.
- Hypothermia and frostbite: Exposure to severe cold can be life‑threatening. Adequate clothing and shelter are essential.
- Livestock and crops: Prolonged snow cover can kill crops and livestock, affecting rural economies.