A low-pressure area is likely to form over the southwest Bay of Bengal in the next 24 hours, according to the Chennai Meteorological Department. Very heavy rain is expected today in six districts—Tirunelveli, Tenkasi, Kanyakumari, Thoothukudi, Virudhunagar, and Ramanathapuram—and heavy rain in 13 other districts including Erode, Coimbatore, and Dindigul.