Expect heavy rain in Chennai, 20 more districts over weekend: RMC

CHENNAI: Chennaiites would do well to carry umbrellas while stepping out over the weekend, with the Regional Meteorological Centre (RMC) forecasting heavy rain in Chennai and several other districts on October 18 and 19.

Heavy rain is expected across Tamil Nadu over the coming days, with widespread rainfall likely to continue until October 26.

VR Durai, director and senior atmospheric scientist, RMC, Chennai, said: “By the end of October, we expect a system to cross the Odisha coast, which will bring more rain to the coastal parts of Tamil Nadu.”

Rainfall in Chennai and neighbouring districts is being driven by two upper-air cyclonic circulations. One lies over north TN and adjoining south coastal Andhra Pradesh at an altitude of 4.5 km to 5.8 km above mean sea level. The other extends from the northern parts of Lakshadweep to the southwest Bay of Bengal across Kerala and TN, at an altitude of 1.5 km to 3.1 km.

On October 20 (Tuesday), heavy to very heavy rain accompanied by thunderstorms and lightning is likely at isolated places in The Nilgiris, Coimbatore, Tirupur, Dindigul, Theni, Tenkasi, Virudhunagar, Tirunelveli and Kanniyakumari. Heavy rain is also likely in Madurai, Tiruchy, Salem, Namakkal, Erode, Karur, Sivaganga, Ramanathapuram, Thoothukudi and Pudukkottai.

“Northeast monsoon rain will be in the evenings and around midnight, while low-pressure systems can bring rainfall during the daytime,” Durai said. “Ghat districts, including Coimbatore and The Nilgiris, adjoining areas and southern districts such as Madurai, Theni, Tenkasi, Virudhunagar, Sivaganga, Tirunelveli, Kanniyakumari, Thoothukudi and Ramanathapuram are likely to receive more rain than the northern coastal districts.”

Moderate rain accompanied by thunderstorms and lightning is expected at many places across the remaining parts of TN, Puducherry and Karaikal until October 23. The maximum temperature is likely to hover around 33 degrees Celsius, while the minimum may dip to 24 degrees Celsius under cloudy skies. Maximum temperatures are expected to remain near normal across TN, Puducherry and Karaikal until October 21.

The highest rainfall recorded on October 17 (Saturday) included 15 cm at Uthiramerur in Kancheepuram and 12 cm at Perambalur. Puducherry and Chengam in Tiruvannamalai, and Ponparappi in Kallakurichi received 10 cm each. Perambur, Madhavaram and Mugaiyur in Villupuram recorded 9 cm each.