Kolkata and other parts of south Bengal were left drenched and struggling on Tuesday after around 251.4mm of rain was recorded in 24 hours until 8.30am. The Alipore Met office recorded the most intense rainfall between 2.30am and 5.30am when 185.6mm of rain fell, with the single highest hourly total touching 98mm between 3am and 4am.
The India Meteorological Department (IMD) on Tuesday afternoon said, ‘The low pressure that formed over the Bay of Bengal on Monday now lies over the coastal areas of Gangetic West Bengal and adjoining north Odisha and northwest Bay of Bengal and is likely to persist for another 24 hours before weakening.’
The associated cyclonic circulation extends up to 7.6km above mean sea level, drawing in strong moisture from the sea. A trough from this system stretches across Odisha to Telangana, keeping rain bands active and maintaining widespread light to moderate rain with isolated heavy to very heavy showers over Kolkata, Howrah, South and North 24 Parganas, East and West Midnapore and Jhargram through Wednesday. Thunderstorms, lightning and gusty winds up to 50 kmph are likely in some pockets.
Rainfall figures across south Bengal underscored the intensity of the downpour. Alipore recorded 25cm, Salt Lake 23cm and Howrah’s Amta 13cm during the 24 hours till Tuesday morning. Extremely heavy rain was also logged in parts of North 24 Parganas. Waterlogging, reduced visibility and damage to kutcha roads remain key risks as the system slowly weakens over the next day.
Adding to the worry, the Met office has flagged another weather system likely to form over the Bay of Bengal around September 25. Moving westwards, it is expected to strengthen into a depression by September 26 and could cross the south Odisha-north Andhra Pradesh coast around September 27. This second system is forecast to bring a fresh spell of widespread rain over South Bengal, including Kolkata, from September 25 to 27, keeping pandal makers and electricians on high alert in the crucial run-up to Durga Puja.
Low-lying neighbourhoods, including Behala, Tollygunge, Salt Lake, Lake Town and parts of central Kolkata were under knee-deep water through the morning. Traffic crawled on roads such as EM Bypass, AJC Bose Road and VIP Road, while several power cuts were reported from waterlogged pockets. Schools and colleges postponed examinations and residents waded through flooded lanes to reach work.