A fresh low pressure area over west-central and adjoining northwest Bay of Bengal, off the north Andhra Pradesh-South Odisha coasts, and an associated cyclonic circulation, are likely to cause heavy rain in Calcutta and coastal districts of Bengal.

The low pressure is likely to intensify in the next 24 hours, causing heavy rainfall coupled with thunderstorm and lightning till Wednesday in the Gangetic region of Bengal.The IMD has put the state on “yellow” alert for the next 48 hours.

It has forecast very heavy rainfall on Sunday and Monday. Squalls with a speed of over 45kmph are expected to lash the coastal region of Bengal adjacent to Odisha over the next 36 hours. A high tide is being feared that could lead to inundation and breaches in earthen dykes in the coastal and riverine belts.Sources said that the weather department had asked people living in the south Bengal districts, including Calcutta, to remain “alert” in view of the forecast.

From Saturday, isolated heavy showers began at many places, hampering normal life.In the fishing harbours of coastal and East Midnapore, police and officials of the state fisheries department have undertaken a massive alertness drive from Saturday. Fishermen and people living in the Canning and Diamond Harbour sub-divisions in South 24-Parganas, and Ramnaga, Contai, Deshapran, Khejuri, Nandigram and Haldia in East Midnapore, have been advised not to venture into sea for fishing or for any other work for the next three days since the sea is likely to be turbulent.

In popular sea resorts including East Midnapore's Digha, Mandarmoni, Tajpur, and Sankarpur, the district administration has restricted movement of tourists.

Additional director of fisheries (marine) of East Midnapore Jayanta Pradhan said, “All the fishermen who went for deep marine fishing have been advised to return. Fishing in the sea has been prohibited till Tuesday".In South 24-Parganas, the district administration has opened control rooms at each sub-division and asked the block administration to monitor the weather in coordination with all allied departments."Owing to the vulnerable location of the district, such weather turbulence has become a normal affair for us. We are prepared to handle any situation," a senior official of South 24-Parganas said in Canning.

The South 24-Parganas district administration has meanwhile prohibited tourist access to sea beaches, including bathing at Bakkhali, Gangasagar, and Fraserganj.In East Midnapore, BDO of Ramnagar-1 Lipon Talukdar, however, said, "We have been monitoring tourist access but sea bathing has not been totally prohibited. We are asking people to be careful and have deployed nulias and civic personnel in large numbers on the beaches."

"The sea was turbulent on Saturday as high waves lashed on the marine drive over the guard wall which the tourists also enjoyed from safe locations under careful watch of the security staff," the BDO said.