Tamil Nadu’s Vellore, Ranipet and Tiruvannamalai districts are likely to receive heavy rain at isolated places on September 21, accompanied by thunderstorms and strong winds, according to a forecast issued by the Chennai weather centre.
The warning covers isolated locations in the three districts and is valid for today. The forecast is significant for residents, road users and local administrations because thunderstorms, strong winds and intense rainfall can affect travel, outdoor activity and local drainage conditions, particularly in built-up areas.
The weather centre has also forecast moderate rain with thunderstorms and strong winds at isolated places in several other districts on September 21. These include the remaining Western Ghats districts, Tirupattur, Krishnagiri, Dharmapuri, Kallakurichi, Erode, Salem, Namakkal, Karur, Tiruchirappalli, Perambalur, Ariyalur, Madurai, Sivaganga and Pudukkottai.
The wider forecast means that rainfall activity is expected across parts of western, central and southern Tamil Nadu, although the intensity is not expected to be the same in all locations. The alert specifically identifies Vellore, Ranipet and Tiruvannamalai for the possibility of heavy rain at isolated places on September 21.
For September 22, the weather centre has forecast moderate rain with thunderstorms and strong winds at isolated places in the Western Ghats districts and southern Tamil Nadu. Light rain with thunderstorms is also likely at isolated locations in other parts of Tamil Nadu, as well as in Puducherry and Karaikal.
The forecast indicates a further shift in rainfall focus towards northern Tamil Nadu on September 23 and 24. Chennai, Kancheepuram, Chengalpattu, Tiruvallur and Ranipet are likely to receive moderate rain on both days, according to the weather centre.
The inclusion of Chennai and the surrounding districts is relevant to the region’s dense urban network, where rainfall can affect road traffic, public transport operations and neighbourhood-level drainage. The forecast does not specify rainfall totals, the duration of individual spells or any closure of public services. It also does not state that widespread heavy rain is expected across the five districts on September 23 and 24.
The weather centre’s forecast is therefore based on the expected conditions at isolated locations and varying levels of intensity across the state. Residents in the districts named for thunderstorms, strong winds or heavy rain should follow updates issued by the weather authorities as the forecast period progresses.
The next forecast period identified in the advisory is September 22, followed by the moderate-rain outlook for Chennai, Kancheepuram, Chengalpattu, Tiruvallur and Ranipet on September 23 and 24.
