CHENNAI: The India Meteorological Department (IMD) has issued a warning of widespread rainfall across Tamil Nadu, with heavy showers expected in at least 21 districts due to atmospheric circulation patterns and other prevailing weather conditions. Coastal regions have also been placed on alert, and fishermen have been strictly advised against venturing into the sea until conditions improve.
The weather is due to cyclonic circulation. Moderate rain with thunderstorms is expected until September 20. Authorities advise caution in low-lying areas.
The IMD explained that the current weather is influenced by an upper-level cyclonic circulation coupled with lower-level convergence across southern India. This pattern is expected to bring moderate rainfall with thunderstorms across most parts of Tamil Nadu, as well as Puducherry and Karaikal.
Chennai witnessed a sudden burst of heavy rainfall on Thursday evening, inundating several neighborhoods and throwing traffic out of gear. Bumper-to-bumper traffic was seen in major roads as a result od heavy waterlogging.
Guduvanchery, Vadapalani, Sholinganallur, Perumbakkam, Ashok Nagar, Mangadu, KK Nagar, Pallavaram, and areas around Chennai Airport received intense showers, with some localities recording over 30mm of rain in a short span.
The downpour led to waterlogging on major roads, causing slow-moving traffic and commuter delays. While most city areas experienced moderate rainfall, the heaviest showers were concentrated southwest of Chennai, particularly around Oragadam and Walajahbad.
The Regional Meteorological Centre in Chennai has issued a yellow alert for widespread heavy rainfall across Tamil Nadu, Puducherry, and Karaikal. Sriperumbudur in Kanchipuram district recorded the highest rainfall of 18 cm in the 24-hour period ending Tuesday morning. This was followed by 13 cm in Manali New Town, Chennai; 10 cm in Guruvaadi, Ariyalur district; and 9 cm each in Korattur, Parimunai, and Ennore in Chennai.
Strong winds reaching speeds of up to 40 km/h are also likely. Officials have noted that moderate rain accompanied by thunderstorms is expected to continue in many parts of the state until 20 September.
Districts likely to witness heavy rainfall at isolated locations include Nilgiris, Erode, Krishnagiri, Dharmapuri, Salem, Tiruvannamalai, Tirupattur, Vellore, Ranipet, Chengalpattu, Kanchipuram, Kallakurichi, Villupuram, Cuddalore, Perambalur, Ariyalur, Tiruchirapalli, Mayiladuthurai, Nagapattinam, Tiruvarur, and Thanjavur. In addition, heavy rainfall is forecast for one or two locations in Tiruvallur, Ranipet, Vellore, and Kanchipuram districts on Thursday.
Chennai and its suburban areas are expected to see cloudy skies with spells of moderate rain, accompanied by lightning and thunder.
The IMD has also issued advisories for coastal regions, warning of squally winds reaching speeds of 40–50 km/h, with gusts up to 60 km/h, over the Gulf of Mannar, Comorin Sea, and adjoining southern Tamil Nadu coastal areas. Fishermen have been strictly warned to avoid venturing into these waters until conditions improve.
Authorities have urged the public to remain cautious in low-lying areas prone to waterlogging and have advised district administrations to maintain high alert for possible flooding and traffic disruptions.
