IMD Forecasts Normal Northeast Monsoon for Tamil Nadu with Late October Onset
Chennai and Tamil Nadu are set to receive a normal Northeast monsoon this year, with conditions turning favourable for its onset starting in the third week of October, the India Meteorological Department announced on Wednesday. The forecast comes as a critical relief after the state logged a 20 percent deficit during the Southwest monsoon season that officially concluded on September 30.
Addressing a virtual press briefing, IMD Director-General Mrutyunjay Mohapatra stated that the state typically registers an average of 44 cm of rainfall during the Northeast monsoon period. While southern and coastal Tamil Nadu are expected to receive normal to above-normal precipitation, north interior districts are predicted to record below-normal rainfall. He added that many parts of the state may see normal to above-normal showers in October, though northern areas could see below-average precipitation alongside above-normal maximum and minimum temperatures.
The upcoming season holds heightened significance following sharp rainfall deficits across multiple districts during the Southwest monsoon. Districts including Chengalpattu, Nagapattinam, Karur, Thanjavur, and Thoothukudi all recorded deficits exceeding 35 percent. Mohapatra noted that prevailing strong El Niño conditions are expected to strengthen through the end of the year alongside a neutral Indian Ocean Dipole, noting that weather systems during El Niño years typically move toward Tamil Nadu, south Andhra Pradesh, and Sri Lanka.
In the immediate term, the Regional Meteorological Centre has forecast a wet spell across the Western Ghats and interior districts extending through the weekend, driven by a north-south trough stretching up to the Gulf of Mannar. Heavy rainfall is predicted at one or two places across Nilgiris, Coimbatore, and Erode districts on Thursday, while interior districts are forecast to experience moderate rainfall.
For Chennai, the Regional Meteorological Centre noted that temperatures could remain above normal at 36 to 37 degrees Celsius on Thursday, alongside the possibility of light rain in some areas. V.R. Durai, Head of the Regional Weather Forecasting Centre, attributed the simmering heat across the region to dry westerlies and strong El Niño influences as the state transitions between monsoons, adding that wind pattern reversals and cloud cover will gradually bring down temperatures.
