In a bulletin on Friday night, the Chennai Meteorological Department has said that moderate thunderstorms and lightning with moderate rain likely at isolated places over Nagapattinam, Mayiladuthurai, Thiruvarur, Ramanathapuram, Thiruppur, Dindigul, Tenkasi, Virudhunagar, Thoothukudi, Thirunelveli Kanyakumari and Karaikal districts.