City that was bracing for the hottest part of the year had a sudden swing in weather on Wednesday, a rarity for April. For the first time in 70 years, Meenambakkam received 103.2 mm rainfall on Wednesday.
Residents woke up to a pleasant monsoon-like day as an upper air cyclonic circulation over Lakshadweep area had brought good rains over many parts of the State since Tuesday night. However, the weather observatory in Nungambakkam recorded only 2.6 mm of rainfall between 8.30 a.m. and 5.30 p.m. The prevailing weather system had brought down the Wednesday temperature to 29.3 degree Celsius, which is five degrees less than the average temperature experienced in April.
Several areas, particularly in south Chennai, had a heavy downpour during morning hours something more like a cloud burst. Rains lashed several places like Taramani, Velachery, Guindy, and Adyar and in just an hour, some places recorded nearly 100 mm of rainfall, which is rare for the season.
S.R. Ramanan, Area Cyclone Warning Centre, Regional Meteorological Centre, Chennai, said moisture was being drawn from the Bay of Bengal across the State and this brought rains over many parts of the State. While northern districts, including Chennai, would have rains till Thursday, wet spell would continue in southern region of Tamil Nadu for a few more days.
Summer rains are usually preceded by an intense period of heat. But this was not one of the typical weather systems that occur during noon. “This type of organised weather activity is rare and May is more likely to get rains than in April. In summer, areas away from the coast get more rains,” said Y.E.A. Raj, former deputy director general of meteorology.
Weather bloggers like Pradeep John point out that the interaction of the cyclonic circulation with another system over Bay of Bengal and constant moisture incursion had brought heavy downpour over the city in April.
K. Ehsan Ahmed who operates a private weather website said in the last 15 years, rainfall over the city crossed 20 mm only twice in April. In, 2001 and 2005, Nungambakkam recorded 83 mm and 60 mm in April.
