Moderate Rain with Thunderstorm and Lightning is very likely to occur at isolated places over Ariyalur, Cuddalore, Kallakurichi, Kancheepuram, Perambalur, Pudukkottai, Ranipet, Salem, Thanjavur, Thiruvarur, Tirupathur, Tiruvannamalai, Vellore, Viluppuram in next 3 hours.