The India Meteorological Department (IMD) has forecast heavy rainfall with thunderstorms in parts of southern India, particularly Tamil Nadu and Andhra Pradesh, over the coming days. This is attributed to a low-pressure system expected to develop in the Bay of Bengal on Saturday, December 7, which is anticipated to intensify and move west-northwestwards, nearing the southwest Bay of Bengal near Sri Lanka by December 12.
According to the IMD, an upper air cyclonic circulation currently extends up to 3.1 km above mean sea level over the Equatorial Indian Ocean and adjoining southeast Bay of Bengal. Under its influence, a low-pressure area is predicted to form over central parts of the southern Bay of Bengal around December 7.
The system is projected to move west-northwestwards and reach the southwest Bay of Bengal off the Sri Lanka–Tamil Nadu coast by December 12.
On Saturday, in Chennai, thunderstorms with light to moderate rain are expected in some areas during the evening or night. Mist or haze is likely during morning hours.
IMD Rainfall Prediction
The IMD's regional forecast has indicated:
December 11: Heavy rain at one or two locations in Tamil Nadu districts including Mayiladuthurai, Nagapattinam, Tiruvarur, Thanjavur, Pudukkottai, Ramanathapuram, and the Karaikal region.
December 12: Heavy rain at one or two places in Chengalpattu, Viluppuram, Cuddalore, and other coastal districts, including Puducherry and Karaikal.
The forecast follows a week after Tamil Nadu faced heavy rainfall and gusty winds due to Cyclonic Storm Fengal, which caused significant disruptions. Beginning with intermittent rainfall on November 29, steady downpours led to waterlogging in coastal regions, deserted roads, and active deployment of civic workers, police, and rescue teams in vulnerable areas.
Districts such as Tiruvannamalai, Salem, and Mayiladuthurai are still recovering from the storm’s impact, grappling with waterlogging and infrastructural damages.