“Due to the Northeast monsoon wind convergence, coastal districts of Tamil Nadu - Tiruvallur, Chengalpattu, Villupuram, Cuddalore, Mayildathurai, Nagapattinam, Tiruvarur, Thanjavur, Thoothukudi, Tirunelveli, and Kanniyakumari is expected to receive moderate rains along with thunderstorm activity for the next 48 hours, and rest of the State to witness light showers. From December 17 (Friday), a few places over South Tamil Nadu will witness rains for the same reason,” said N Puviarasan, Director, Area Cyclone Warning Centre, Regional Meteorological Center (RMC).