CHENNAI: Chennai and its neighbouring areas are expected to receive rainfall accompanied by thunderstorms next week that would bring down the temperatures, as the southwest monsoon is beginning to weaken, said weather experts.

Meanwhile, the Regional Meteorological Centre (RMC), Chennai, has issued very heavy rainfall warnings for the Nilgiris and the ghat areas of Coimbatore. Heavy rainfall alerts have also been issued for isolated places in Theni, Tenkasi, and the ghat regions of Tirunelveli.

Between July 27 and August 1, light to moderate rainfall is likely to occur at isolated places across Tamil Nadu, Puducherry, and Karaikal, according to the forecast issued by RMC.

In Chennai, light rain or drizzles are expected over the next few days, with the sky remaining partly cloudy during most of the day.

K Srikanth, a weather blogger, explained that the weakening southwest monsoon over the Western Ghats is likely to lead to increased wind instability in the region. “This will result in light showers accompanied by thunderstorms in Chennai. Temperatures are expected to remain below normal,” he said.

The southwest monsoon has been a mixed bag for Tamil Nadu, with several districts reporting deficient rainfall, while a few, including Chennai, have received above average rainfall. In percentage terms, Thoothukudi recorded the worst with -97 per cent, closely followed by Karur with -95 per cent. In all, 28 of the 40 met divisions, including Puducherry and Karaikal, recorded deficient rainfall from June 1 to July 26.

On the other hand, Tirunelveli received a whopping 339 per cent excess rainfall, while it was 125 per cent in Tenkasi, and 96 per cent in Theni. It was 30 per cent excess in Chennai, 28 per cent in Tiruvallur, 3 per cent in Chengalpattu, but -3 per cent in Kancheepuram, show data from RMC.