THUNDERSTORM

About:

• Thunderstorms are severe weather events associated with frequent lightning, high winds, and heavy rainfall. They are so called because of the thunderous loud noise they make because of thunder.
  
  
• Important characteristic of Thunderstorms: Formation of Squall, strong updraft and down draft, towering cumulonimbus associated with turbulence and icing, in cloud electrification and associated lightning, localized Strong rain and hailstorm.
  
  
• When do they occur? They can and do occur at any time of the year, but are most likely to happen during the afternoon and evening hours and during the spring and summer seasons.
  
  
• Types: Considering the intensity, the thunderstorms in India are categorised as –
  • Moderate thunderstorm: if there are loud peals of thunder with frequent lightning flashes, moderate to Strong rains and maximum wind speed 29 to 74 kmph
    
    
  • Severe thunderstorm: if there is continuous thunder and lightning, Strong rains and maximum wind speed ≥ 75 kmph.
    
    
  
  
  
• Reason for their occurrence in India: The heating of North Indian plains during peak monsoon season, clubbed with winds bringing moisture from the Arabian Sea, the Bay of Bengal or due to a western disturbance, forms conditions that lead to formation of a thunderstorm.
  
  

Recent Development:

• A team of scientists from the India Meteorological Department (IMD), the Indian Institute of Tropical Meteorology (IITM) and the National Centre for Medium Range Weather Forecasting (NCMRWF) are working on models to forecast thunderstorms well in advance.
  
  
• The IMD, the IITM and NCMRWF work under the Ministry of Earth Sciences.
  
  
• The IMD plans to have Standard Operating Procedures (SOPs) in place by April for dealing with thunderstorm instances. Sending early warnings to States will give them more time to respond.
  
  
• Background: In May 2018, over 200 people died in thunderstorm incidents. In Rajasthan and Uttar Pradesh alone, violent winds killed nearly 180 people.