August rainfall level in TN set to be highest in a decade

Officials from Regional Meteorological Centre (RMC), Chennai, said that until 5.30 pm on August 16, Nungambakkam had recorded 13.2mm of rainfall while Meenambakkam has recorded 17.4mm. Tamil Nadu, on August 16, recorded 7 mm of rainfall, overall.

RMC statistics show that from June 1 to August 16, Tamil Nadu has received 204 mm of rainfall while normally, the state receives 153.9 mm during this period. This amounts to an excess of 32 percentage departure from normal (PDN). S Balachandran, Director, RMC, said, “This is above normal rainfall in August. Rains or thunderstorms are likely to occur at many places over TN and Puducherry. There is a trough from north Tamil Nadu to south.”

Pradeep John, who blogs at Tamil Nadu Weatherman, said that the 32% excess is due to an extended break monsoon. “The break monsoon scenario results in above normal rainfall in Bihar, Jharkhand, Assam and helps Tamil Nadu. The extended break monsoon over the last 15 days has been helping our state get rains. Except for Kanyakumari, Nilgiris, Tirunelveli and to a certain extent, Namakkal, the rest of Tamil Nadu received good convective rainfall. In fact, August this year has already received 114.1 mm rainfall, which is more than the average rainfall for the entire month of August during the previous five years,” said the weather blogger, forecasting that there will be regular rains with intermittent gaps across Tamil Nadu. “If this continues, there is a good chance that Tamil Nadu breaks the 2007 record of 151 mm of rainfall,” he added. 

Yet, most dams in and around the city remain parched. Mettur Dam, which has a total level capacity of 120 feet, had reached 46.660 feet on Wednesday. “The inflow was 20,011 cusecs while outflow (drinking water supply) was 556 cusecs. In addition, 54,990 cusecs from Krishna Raja Sagar dam and 2646 cusecs from Kabini dam were released to Mettur. Totally, the water is at 46.6608 feet and is used for drinking water supply only. Once the water level reaches 90 feet, it will be released for irrigation in the Cauvery delta region.

These rains are sufficient to fill up small waterbodies and recharge groundwater. K Srikanth, who blogs at Chennaiyil Oru Mazhaikalam (COMK), said that these rains have not really helped fill up dams.