The Regional Meteorological Centre (RMC) in Kolkata said the low pressure area formed over the northwest Bay of Bengal had become more pronounced in the last few hours and was expected to intensify into a depression by late Monday.
The monsoon axis extends over the low pressure area to the Bay of Bengal via Punjab, Haryana, Uttar Pradesh and Jharkhand. As a result, continuous heavy rain is likely in south Bengal till Tuesday.
On Tuesday, isolated heavy rainfall is also expected in West Midnapore, Jhargram, Purulia, Bankura, West Burdwan and Birbhum districts. The remaining districts of south Bengal will experience rain with thundershowers. Rain is likely to decrease in south Bengal from Tuesday evening onwards. No further weather warning has been issued for now.
Due to the low pressure system, gale force winds of 40 to 50 kmph are blowing over the sea. Fishermen have been advised not to venture into the north Bay of Bengal off the West Bengal and Odisha coasts till Tuesday.
Heavy rain will also continue in north Bengal till Tuesday. Heavy rain is likely only in Jalpaiguri and Kalimpong districts on Monday, while Alipurduar and Darjeeling districts may see heavy rain on Tuesday. Scattered rains with thundershowers will continue in the remaining northern districts, including North Dinajpur, South Dinajpur, Malda and Cooch Behar, till Tuesday.
Since Monday morning, Kolkata has been witnessing heavy rain that left several areas waterlogged. Continuous rainfall has slowed traffic movement in and around the city. The minimum temperature in Kolkata on Monday morning was 25 degrees Celsius, 1.5 degrees below normal. The maximum temperature on Sunday was 30 degrees Celsius, 1.9 degrees below normal.