Tamil Nadu orange alert conditions are expected across 17 districts on October 22, with the Chennai Regional Meteorological Centre warning of very heavy rain accompanied by thunderstorms and lightning. The alert follows the formation of a low-pressure area over the southwest Bay of Bengal and comes as heavy rain is forecast to continue in the state until October 26.
The districts under the orange alert are Thoothukudi, Tirunelveli, Kanniyakumari, Tenkasi, Virudhunagar, Ramanathapuram, Theni, Dindigul, Madurai, Coimbatore, Nilgiris, Sivaganga, Pudukkottai, Thanjavur, Tiruvarur, Nagapattinam and Mayiladuthurai. The warning was issued for rain of 11 to 20 centimetres within 24 hours.
V.R. Durai, director of the Chennai Regional Meteorological Centre, said the low-pressure area was influencing weather conditions over southern Tamil Nadu. The forecast covers several major urban and peri-urban areas, including Madurai and Coimbatore, as well as districts along the southern and Cauvery delta regions.
The alert also includes districts where intense rainfall can affect road movement, local drainage systems and access between urban centres and surrounding settlements. However, the source report does not provide specific forecasts of flooding, road closures, transport cancellations or municipal advisories for individual cities.
An additional set of districts has been placed under a forecast for heavy rain and thunderstorms. These are Tiruchirappalli, Erode, Ariyalur, Perambalur, Cuddalore, Namakkal, Viluppuram, Tiruppur and Karur, along with Puducherry. Chennai and its suburban areas are expected to remain cloudy, with moderate rain possible in isolated locations.
The weather office classifies rainfall of 6 to 11 centimetres as heavy rain and issues a yellow alert. Rainfall between 11 and 20 centimetres is classified under an orange alert, while precipitation above 20 centimetres attracts a red alert. These thresholds are used to communicate the expected intensity of rainfall and the level of preparedness required.
The forecast places southern Tamil Nadu and parts of the western and delta regions under heightened weather watch as the low-pressure system affects the state. The meteorological centre has said that heavy rain may persist through October 26, with the immediate orange alert applying to October 22.
