Why in the news?
- A severe blizzard struck the eastern face of Mount Everest in Tibet, trapping nearly 1,000 trekkers in the remote Karma valley.
Blizzard
- What is it?: A blizzard is a severe snowstorm characterized by strong sustained winds (≥ 56 km/h or 35 mph) and low visibility (less than 400 metres) lasting at least 3 hours.
- Areas Affecting:
- Global: Polar and temperate regions.
- India: Himalayan regions (Ladakh, Himachal Pradesh, Uttarakhand, Arunachal Pradesh)
- Causes
- Cold polar air masses meeting warm, moist air from lower latitudes.
- Formation along low-pressure systems where frontal lifting causes heavy snowfall.
- Strong pressure gradients create high wind speeds, blowing loose snow and reducing visibility.
- Types
- Ground Blizzard: Snow already on the ground is blown by wind; no fresh snowfall.
- Lake-Effect Blizzard: Moisture from a lake evaporates into cold air, forming intense localized snowfalls (e.g. Great Lakes region, USA).
- Nor’easter (in North America): Powerful winter storm moving up the eastern coast, bringing blizzard-like conditions.
- Effects
- Transport disruption: road, rail, air closures.
- Power outages due to ice accumulation on lines.
- Livestock and crop losses in rural areas.
- Frostbite and hypothermia risks for humans.
- Economic losses from halted activity and emergency response.
- Preparedness & Mitigation:
- Early warning systems by meteorological agencies.
- Shelters and heating infrastructure in snow-prone areas.
- Snow fencing and tree belts to reduce drifting.
- Emergency kits and public awareness campaigns.