Chennai, districts receive showers as northeast monsoon onset nears; heavy rain forecast across TN

CHENNAI: Rain has begun in parts of Chennai and its suburbs, with very heavy showers reported around Tambaram on Wednesday afternoon, even as the Regional Meteorological Centre (RMC), Chennai, said conditions were favourable for the onset of the northeast monsoon over southern parts of South India. The southwest monsoon is likely to withdraw completely from the rest of the country on Thursday (October 15), it said.

Moderate showers are currently occurring in several parts of Chennai, including Adyar, Besant Nagar and Saidapet, bringing relief from the heat.

Weather blogger Srikanth K, who runs the Chennai Rains X handle, advised office-goers to keep track of weather radar activity before stepping out over the coming months as rainfall associated with the onset of the northeast monsoon becomes more frequent.

Tamil Nadu Weatherman, an X handle run by weather blogger Pradeep John, noted that intermittent spells of rain and sunshine, with heavier rainfall during early mornings and nights, were typical of the northeast monsoon. He added that interior districts of Tamil Nadu would also receive rainfall, not just coastal areas.

Rain bands move inland across Tamil Nadu

According to Chennai Rains' experimental, automated rainfall nowcast based on IMD radar data, heavy spells were reported in parts of Tiruchirappalli and Kallakurichi districts, while Villupuram received moderate rainfall. At noon today, rain bands were also seen approaching Thanjavur, with isolated showers reported in Ramanathapuram, Chengalpattu and 13 other districts, according to weather blogger Srikanth.

Srikanth also noted that the Cauvery delta region was experiencing intermittent moderate to heavy rainfall amid a cyclonic circulation over the southwest Bay of Bengal, indicating strengthening easterlies.

Isolated thunderstorms were also reported over northern Tamil Nadu, with some moving in from southern Andhra Pradesh, which had experienced moderate to heavy rainfall earlier in the day, he added in his tweet.

Isolated heavy showers predicted in TN till October 20

The Regional Meteorological Centre (RMC), Chennai, said on Tuesday (October 13) that an upper-air cyclonic circulation that was previously over the Gulf of Mannar and adjoining the south Tamil Nadu coast had moved over the southwest Bay of Bengal off the south Sri Lankan coast. A trough in easterlies extended from this circulation towards the central Bay of Bengal.

The India Meteorological Department (IMD) has forecast isolated heavy rainfall over Tamil Nadu, Puducherry and Karaikal on October 14. Isolated heavy rainfall is also forecast over the region from October 16 to 20.