EARTH IS WARMING FASTER

Changes in weather systems, once expected decades hence, appear to be unfolding now. In India the consequences are intensifying

- AKSHIT SANGOMLA

THEY ARE akin to aliens in the world of meteorology—unimaginable and unpredictable. And now they seem to be invading. That, at least, was how it felt when cloudburst-like downpours lashed much of India’s plains in the monsoon months of August and September.

Meteorologists define cloudburst as rainfall exceeding 100 mm in an hour over an area of 20 to 30 sq km. Such events are typically confined to hilly terrain. But on August 30, the Manali area of Chennai, Tamil Nadu’s coastal capital, recorded 106 mm of rain in an hour starting at 10 pm. A second spell, from 11 pm to midnight, brought another 127 mm. In the same hour nearby Wimco Nagar saw over 157 mm of rainfall, Korattur recorded 137 mm, and New Manali received 103 mm of rains. The city as a whole experienced five cloudbursts or cloudburst-like events within two hours. Just two days earlier, Kamareddy city of Telangana, had endured 576 mm of rain in 48 hours—its heaviest downpour in 35 years. Much of it fell within just a few hours.

Meteorological records show that several blocks of the district received more than 300 mm during that period.

Such rain events also struck other states. Rain-shadowed Nanded, in Maharashtra, received 206 mm rainfall on August 17-18. Between the mornings of September 22 and 23, Kolkata was drenched with 251 mm of rainfall—highest for any September day in the last 39 years and the sixth highest in the city’s history. Of this, 180 mm fell within three hours; 98 mm in a single hour.