August may end on a wet note, with thunderstorms expected to return over some parts of the State on Thursday. This has been one of the wettest southwest monsoon seasons on record in the past five years.
The thunderstorms that brought rainfall consistently on several days this August have pushed the State’s rainfall to 244 mm so far this season, which is 21% more than the average for the period since June 1.
‘Highest in 5 years’
S. Balachandran, Director, Area Cyclone Warning Centre, said this is one of the highest volumes in the past five years. However, this does not mean that all districts have had a good spell of rain.
“We do have districts such as Kanniyakumari and Nilgiris that have received poor rainfall this season. We expect the rainfall activity to increase over the State from Saturday. While many parts of the State may get moderate rainfall, it may be heavy in one or two places in south Tamil Nadu,” he said.
Chennai too is on its way to recording one of the wettest seasons in August in the past decade after evening showers, which almost became a daily affair this month. The city recorded 285.9 mm, which is its second-best rainfall in August in the past decade. It had received its highest volume of rainfall of 368.9 mm in August 2011.
According to data of the Meteorological Department, Chennai had registered heavy rainfall exceeding 300 mm during August only in three years during the past five decades.
While the copious rainfall this month has saved city’s water table from further depletion, it did not help much to boost the storage position in city’s reservoirs. Experts note that the reservoirs would need a more intense rain spell, which is common in the northeast monsoon, to replenish storage.
Y.E.A. Raj, former deputy director general of meteorology, Chennai, said that whenever there is a break monsoon situation due to weak westerlies in northern India, it proves favourable for Tamil Nadu, bringing more thunderstorms particularly during August. This year too was one such time when Tamil Nadu gained more from the southwest monsoon.
Meanwhile, the Meteorological Department forecasts scattered rainfall to occur on Thursday over the State. Chennai too may get rain or thundershowers during evenings till Friday.