Short spells of heavy showers

Short spells of heavy showers

News:

1. Mini-cloud bursts are increasing in India

Important facts:

2. A mini-cloud burst is defined as rainfall in excess of 50 mm in two consecutive hours.
3. The term was coined by the scientists at Pune’s Indian Institute of Tropical Meteorology(IITM) due to an increase in heavy rainfall of short durations during the summer monsoon in India.
4. Researcher’s finding:

• The researchers found an average of 200 mini-cloud bursts occurring every year in India.
• Between 1988 and 2007, there were around 265 mini-cloud bursts.
• Over most parts of India, the highest recorded rainfall in two hours is 100-150 mm
• The locations (other than the mountainous regions of Himalayas) that have recorded rainfall of over 150 mm in two hours are those that also experience cloud bursts.
• The study found that mini-cloud bursts are “very common” in the foothills of the Himalayas.
• The west coast records more than three mini-cloud bursts per season, the Indo-Gangetic plains and the Saurashtra region receive two per season.
• Rajasthan and States to the east of the Western Ghats experience the least number of mini-cloud bursts.
• For the rest of India, the amount of rainfall per mini-cloud burst is 50-70 mm.

5. Comparison with Cloud burst:

• The Indian Meteorological Department recognized cloud bursts-  heavy rainfall, in the mountainous regions of Himalayas .
• In contrast, mini-cloud bursts are indicative of torrential downpour but of lower intensity than cloud bursts.

6. Classification of rainfall:

• Presently, the IMD classifies rainfall as heavy (over 60.5 mm), very heavy (over 130 mm) and extremely heavy (over 200 mm).