How common are cloudbursts in India?, Pg12

Key Highlights:

• The India Meteorological Department (IMD) defines a cloudburst as 10 cm or more of rain in an hour over a small area of 20-30 sq. km.
• Cloudbursts are relatively rare but are becoming more frequent due to global warming, which increases the atmosphere's moisture-holding capacity.
• Between 1970 and 2016, the IMD recorded approximately 30 cloudburst incidents, though experts believe this is an underestimate due to monitoring challenges in remote, high-altitude regions.
• States like Uttarakhand, Himachal Pradesh, and Jammu and Kashmir have recently reported a surge in such events, particularly during July and August.
• The IMD is developing 'nowcasting' technology for short-term alerts and plans to expand its radar network under Mission Mausam to improve hyperlocal event prediction.

Coludburst.jpg

Detailed Insights:

• A cloudburst involves an extraordinary amount of rainfall over a small area, leading to rapid and voluminous flooding as the ground cannot absorb the water quickly enough.
• Some scientists propose a 'mini-cloudburst' category for 5 cm of rain in an hour over the same area, recognizing its potential for devastation depending on topography.
• Cloudbursts typically form through convection, where warm, moist air rises rapidly, often intensified by orographic lifting in mountainous regions.
• Strong updrafts suspend water droplets in towering cumulonimbus clouds until their weight or weakening updrafts cause them to plummet.
• Mislabeling heavy rainfall as a 'cloudburst' can obscure human negligence, such as illegal construction, deforestation, and poor drainage, by attributing disasters solely to unforeseeable natural acts.
• Forecasting cloudbursts is challenging because they occur over areas smaller than typical weather model grid cells and develop rapidly, unlike larger weather systems.
• Mountainous terrain, where cloudbursts are common, poses difficulties for weather monitoring due to radar blind spots and sparse automatic weather stations.
• Mission Mausam, a government initiative, aims to significantly enhance India's weather and climate forecasting capabilities by doubling the radar network and integrating AI for better prediction of hyperlocal events.

Scientific/Technical Concepts Involved:

• Cloudburst: An extreme weather event defined by the IMD as 10 cm or more of rainfall in an hour over a small area of 20-30 sq. km.
• Nowcasting: A meteorological technique for issuing very short-range, highly detailed weather forecasts, typically for the next few hours.
• Orographic Lifting: The process where air masses are forced upwards by the physical presence of elevated terrain like mountains, leading to cooling and condensation.
• Cumulonimbus Clouds: Dense, towering vertical clouds associated with thunderstorms, heavy rainfall, and strong updrafts, crucial for cloudburst formation.
• Mission Mausam: A government initiative by the Ministry of Earth Sciences to enhance India's weather and climate services through advanced observation, modeling, and early warning systems.