Chennai: Schools were closed and umbrellas were out on Tuesday as the city and the neighbouring districts experienced intermittent rainfall, triggered by a low-pressure system hovering off the north Tamil Nadu-south Andhra Pradesh coast, for the second consecutive day. IMD has forecast more heavy rainfall for the next two days. It has issued a yellow alert for the city and neighbouring districts of Kancheepuram, Tiruvallur, and Chengalpet.
A heavy rainfall alert has also been issued to eight other northern and southern districts on Wednesday and to 23 north, coastal, south, and western districts on Thursday.
"The rain activity will be of the same intensity as it was on Tuesday. People need not panic. The low-pressure is a weak feeble system. There is no possibility for it to strengthen further as it is already near the coast and is likely to move westwards slowly," said S Balachandran, deputy director general, IMD.
On Wednesday, the city and suburbs are likely to receive moderate to heavy rainfall over some areas. Skies may be partly cloudy, and the temperatures may be at a maximum of 30C and a minimum of 24C-25C.
City's southern localities got heavy overnight rain. A gauge in Perungudi recorded the highest of 9cm, followed by areas such as Alandur, Meenambakkam, and Adyar, which recorded 6cm. Nungambakkam and Meenambakkam observatories recorded 6cm and 4cm. The rain activity on Monday night led the IMD to upgrade the yellow alert to orange on Tuesday. But the rain intensity and frequency reduced during the day. Till 7:30 pm, Nungambakkam and Meenambakkam recorded 8.1mm and 5.2mm.
Balachandran said there was not much rain activity since mid-Oct due to several factors such as back-to-back weather systems over the Bay that reduced the air-sea energy exchange, absence of triggering systems such as the Madden-Julian Oscillation, a large-scale eastward-moving weather pattern, Rossby waves, and a drop in the speed of easterlies.
Since Oct 1, Tamil Nadu recorded 26cm of rain, which is a 1% deficit.