A deep depression over the Bay of Bengal will bring scattered rains to coastal Tamil Nadu for three days from Friday, January 9, 2026. This is a rare event, as only 20 intense weather systems have formed in the Bay during January since 1891. The Regional Meteorological Centre (RMC) said the depression lies about 810 km southeast of Karaikal and 980 km south-southeast of Chennai. It is likely to cross the Sri Lanka coast between Hambantota and Kalmunai on Friday evening or night. B. Amudha, Head (Additional in-charge) of RMC, said, "While this is not the first time that the Bay has churned out intense weather systems during January, such events are not frequent." The deep depression is expected to bring heavy rainfall to some parts of south-coastal Tamil Nadu as it moves along. The RMC has issued orange and yellow alerts due to possible intense rainfall reaching up to 20 cm in some districts. On Friday, heavy to very heavy rains will hit Tiruvarur and Nagapattinam. Ramanathapuram, Pudukottai, Mayiladuthurai, and Thanjavur may get heavy rainfall. On Saturday, rain is expected in many coastal and some interior districts, especially between Chengalpattu and Ramanathapuram. Four districts including Cuddalore and Tiruvarur may receive heavy to very heavy rainfall. Isolated heavy rain may occur in seven other districts, including Pudukottai, Chengalpattu, and Ariyalur. Former deputy director general of meteorology, Y.E.A. Raj, noted the current system is similar to the January 2023 depression that crossed Sri Lanka's east coast. He said, "Eleven intense weather systems formed over the Bay of Bengal between 1961 and 2024, and most of them were short-lived. None crossed the Tamil Nadu coast. Only two January systems in 1967 and 2005 intensified into cyclonic storms." Additionally, the RMC forecasts ground frost on Friday over the Nilgiris and Kodaikanal hills.