“Due to Southwest monsoon winds, the coastal districts of Tamil Nadu including Chennai, Chengalpattu, Villupuram, Cuddalore, Mayiladuthurai, Tiruvarur and Nagapattinam, and adjoining interior districts are likely to experience moderate to heavy rain along with thunderstorm activity. Meanwhile, light rain is likely over the rest of Tamil Nadu, Puducherry and Karaikal for the next 48 hours,” said N Puviarasan, director, Area Cyclone Warning Centre, RMC, Chennai.