Low pressure brewing over Bay of Bengal, heavy rain likely this week
The Statesman | 28 May 2025
A cyclonic circulation over the west-central and adjoining north Bay of Bengal is intensifying into a low-pressure system, with the India Meteorological Department (IMD) forecasting its formation later today. According to Somnath Dutta, director (Eastern Region) of the Alipore Met Office, the system is associated with a trough extending from Marathwada to the northeast Bay of Bengal, located approximately one kilometre above mean sea level.
This development is drawing moist winds from the southeast into southern West Bengal, leading to consistent rainfall across the region. The IMD has warned of heavy to very heavy rainfall over several districts of West Bengal through the week, with the possibility of extremely heavy rain on Thursday and Friday. Cloudy skies and moderate rain with lightning are expected in Kolkata and surrounding areas today. The city’s maximum and minimum temperatures are likely to hover around 32°C and 26°C, respectively. The southwest monsoon is advancing under favourable conditions and is expected to reach sub-Himalayan West Bengal and Sikkim within the next three days. It has already covered parts of northeastern India, including Assam and Meghalaya. Under the influence of the low-pressure system, sea conditions are expected to be rough. Fishermen have been advised not to venture into the deep seas of the north and central Bay of Bengal from 28 May through Saturday. Similar restrictions are in place along the coasts of West Bengal and Odisha. Districts including North and South 24 Parganas, East and West Midnapore, Jhargram, Kolkata, Howrah, Hooghly, Bankura, and West Burdwan are forecast to receive heavy rainfall on Thursday. On Friday, alerts for very heavy to extremely heavy rainfall were issued for East and West Burdwan, East and West Midnapore, Bankura, Birbhum, and Hooghly, with rainfall potentially reaching 200 mm in some areas. In north Bengal, while Tuesday and Wednesday may see light to moderate rain, heavy to extremely heavy rainfall is expected from Thursday onward.
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Districts such as Darjeeling, Kalimpong, Alipurduar, Cooch Behar, and Jalpaiguri are likely to witness intense downpours through the weekend, with isolated spots receiving up to 200 mm of rainfall. Malda and both North and South Dinajpur may also receive heavy rainfall. Despite brief relief from thunderstorms, humidity remains high in Kolkata due to abundant moisture in the air, contributing to discomfort when rain subsides. Relative humidity ranged from 77 per cent to 97 per cent on Tuesday, with a recorded high temperature of 31.3°C and a low of 25.8°C. Rain activity is expected to intensify beginning Wednesday.