Weather system expected to bring scattered rain over coastal T.N. from January 7

RMC Chennai to announce Northeast monsoon withdrawal around Pongal, with scattered rain expected from January 7.

The Regional Meteorological Centre (RMC), Chennai, is likely to announce the withdrawal of the Northeast monsoon only around Pongal as a weather system is likely to bring scattered rain particularly over coastal Tamil Nadu from January 7.

Though the RMC considers December 31 as the end of Northeast monsoon for statistical reasons, the monsoon continues to prevail over the State. S. Balachandran, Additional Director General of Meteorology, Chennai, said an easterly wave or an upper air circulation was expected to bring scattered rainfall of moderate intensity over coastal Tamil Nadu and isolated places in the interior districts on January 7 and January 8.

Noting that the previous year’s Northeast monsoon spilled over to January 14 in 2024, he said there could be a similar pattern this year too. The State had a surplus Northeast monsoon as it registered 58.8 cm of rainfall, which would be 33% more than its average between October 1 and December 31.

Easterly wave activity and Madden Julian Oscillation, a global weather phenomenon that significantly influences the weather pattern, turning favourable for the State in October and December brought copious rainfall. Last year saw four cyclones and many weather systems of varying intensities, including depressions, Mr. Balachandran said.

The State has been experiencing dry weather since Wednesday. In its bulletin, the RMC said isolated rainfall was possible in one or two places in Tamil Nadu, Puducherry, and Karaikal. There may be a slight increase in rainfall from January 7. Chennai might record a day temperature of 30-31 degrees Celsius on Friday, with mist or haze expected in the early morning hours.

In its monthly outlook, the India Meteorological Department (IMD) has predicted above normal day temperature over coastal Tamil Nadu in January. Interior parts and districts along the Western Ghats are likely to have normal or below normal maximum temperature this month. Nights may turn warmer this month as the IMD has indicated above normal minimum temperature in its probability forecast for January.

The IMD, however, said the State could experience normal or below normal day temperature during the winter months (January and February).