The Met Department on Wednesday forecast the likely formation of a low pressure area over northeast Bay of Bengal on September 24, even as several low-lying areas in and around the metropolis remain submerged following torrential rainfall earlier in the week.

The weatherman warned of downpour at one or two places in South 24 Parganas, Purba Medinipur and Paschim Medinipur districts on September 26-27, and rain or thundershowers across most districts of South Bengal, including Calcutta.

A cyclonic circulation lies over the Myanmar coast, which is likely to move to northeast Bay of Bengal and intensify into a low pressure on September 24, it said.

Calcutta recorded the heaviest one-day rainfall for September in 13 years - 142mm in 24 hours - on Monday, Met office data showed.

Mukundapur, where numerous hospitals are located and Rahara, where three members of a family were electrocuted in a waterlogged room on Tuesday, are among the places still submerged, officials said.