CHENNAI: A depression over the east-central and adjoining southeast Bay of Bengal is likely to intensify into a deep depression and further develop into a cyclonic storm by the morning of October 26, the India Meteorological Department (IMD) said on Saturday, forecasting heavy to extremely heavy rainfall in several parts of Tamil Nadu and Puducherry over the next two days.

The system, moving west-northwestwards, is expected to intensify as it approaches the west-central Bay of Bengal near the Andhra Pradesh coast by October 28.

The IMD has forecast extremely heavy rainfall at isolated places in Theni, Dindigul and Madurai on Sunday. Heavy to very heavy rain accompanied by gusty winds of 40-50 kmph is likely in Cuddalore, Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Pudukkottai, Ariyalur, Perambalur, Tiruchy, Karur, Nilgiris, Coimbatore, Tirupur and Sivaganga, besides Karaikal.

Isolated heavy rain is also expected in Tiruvallur, Chennai, Chengalpattu, Kancheepuram, Villupuram, Kallakurichi, Vellore, Ranipet, Tirupattur, Tiruvannamalai, Namakkal, Salem, Dharmapuri, Krishnagiri, Erode, Virudhunagar, Kanniyakumari and Puducherry.

On Monday, heavy to very heavy rainfall is likely to continue in Pudukkottai, Sivaganga and Ramanathapuram districts. Isolated heavy rain accompanied by squally winds is forecast in The Nilgiris, Coimbatore, Theni, Dindigul, Madurai, Virudhunagar, Tenkasi, Thoothukudi, Tirunelveli and Kanniyakumari.

In Chennai, the maximum temperature is likely to hover around 32 degrees Celsius and the minimum around 25 degrees Celsius. Maximum temperatures across Tamil Nadu, Puducherry and Karaikal are expected to remain near normal until October 28.

The IMD has warned of hazardous sea conditions as the system intensifies. The sea is likely to be very rough to high over the central and adjoining southeast Bay of Bengal from Sunday morning, becoming high to very high over the west-central and east-central Bay of Bengal between October 26 and 28. Rough to very rough conditions are also expected along the Andhra Pradesh and Odisha coasts.

Fishermen have been advised not to venture into deep waters and to plan their activities strictly in accordance with official advisories through October 28.