Some parts of Tamil Nadu to receive isolated rainfall till September 22

Southwest monsoon is weak over the State, says IMD officials

Some parts of the Western Ghats and coastal Tamil Nadu are likely to receive light to moderate rain till Sunday. Most parts will experience a subdued weather for a week as southwest monsoon is weak over the State, according to the India Meteorological Department.

Chennai, too, has chances of thunderstorms and lightning, with light or moderate showers, in some areas till Thursday. Overnight showers in some areas kept the day temperature close to the normal in the city on Tuesday. The weather stations at Nungambakkam and Meenambakkam recorded a maximum temperature of nearly 34 degrees Celsius.

During the past 24 hours ending 8.30 a.m. on Tuesday, Gudalur Bazaar in Nilgiris district received the highest rainfall of 4 cm in the State for the day. The weather stations in and around the city, including Villivakkam, Nungambakkam, Red Hills and Cholavaram, received 2 cm each.

But clear sky over several places led to a rise in day temperature. While Thoothukudi recorded a maximum temperature of 38.4 degrees Celsius, four degrees above average, Karur Paramathi recorded 35.8 degrees Celsius, three degrees above average. Convective activity, too, triggered isolated rainfall.

IMD officials said the variations in the speed of westerly winds influenced such isolated rainfall. There was no specific system that would trigger large-scale rainfall over the State.

The wind flow was oriented towards the low pressure area that lies over the northwest Bay of Bengal and the adjoining Odisha-West Bengal coasts. This meant weak monsoon activity over Tamil Nadu for a week, officials added. However, the southwest monsoon is yet to begin its withdrawal from the country.

The State has so far received 46.1 cm, which is 62% more than the average for the southwest monsoon, since June 1. Most parts of the State have received surplus rainfall this season, except for Kanniyakumari and Karaikal.