Chennai: A low-pressure area over the Bay of Bengal is expected to intensify into a cyclonic storm by the morning of 27 October, the India Meteorological Department (IMD) announced on Friday.

With the Northeast monsoon now active, Tamil Nadu is set to receive widespread rainfall over the next two to three days as the system develops.

According to the IMD, the low-pressure area over the southeast Bay of Bengal has been moving slowly west-northwestwards and has remained nearly stationary over the same region.

“It is likely to move west-northwestwards, intensify into a depression over the southeast and adjoining central Bay of Bengal by 25 October, further into a deep depression by 26 October, and into a cyclonic storm over the southwest and adjoining west-central Bay of Bengal by the morning of 27 October,” the IMD bulletin stated.

Heavy rainfall has already been recorded in several parts of Tamil Nadu during the past 24 hours. Pallipattu in Tiruvallur district registered the highest rainfall at 15 cm, followed by Nalumukku in Tirunelveli at 12 cm. Sriperumbudur in Kancheepuram district saw the lowest, with 1 cm of rain, according to the department’s latest update.

The IMD said the low-pressure system had formed under the influence of an upper air cyclonic circulation early on Friday morning.

Light to moderate rain accompanied by thunderstorms and lightning is expected over Tamil Nadu, Puducherry, and Karaikal until 28 October. Heavy rainfall is likely at isolated places in Cuddalore, Puducherry, Villupuram, and Chengalpattu districts, the IMD added.

For Chennai and nearby districts, the sky will remain partly cloudy, with maximum temperatures around 29°C and minimums between 24°C and 25°C. “One or two spells of light to moderate rain accompanied by thunderstorms and lightning are likely over the next 24 to 48 hours,” the IMD forecast said.