Moderate rain with thunderstorm with Lightning is likely to occur at isolated places over Chengalpattu, Dharmapuri, Kallakurichi, Kancheepuram, Krishnagiri, Perambalur, Ranipet, Thiruvallur, Tiruchirappalli, Tirupathur, Tiruvannamalai, Vellore, Viluppuram in next 3 hours.