CHENNAI: Madurai city was the hottest place in the country on Tuesday, with the IMD observatory at Madurai Airport recording 42.5°C, around 5.5 degrees above normal. Another station in the city logged 41.6°C, about 5.7 degrees above normal, as weak southwest monsoon conditions triggered heatwave-like weather across interior Tamil Nadu. Meteorologists said relief may arrive on Friday when rain activity is expected to become widespread. V R Durai, director, Area Cyclone Warning Centre, IMD Chennai, said the intense heat was linked to a weak low-level jet (Somali Jet), a narrow band of strong southwesterly winds about 1.5km above Arabian Sea that normally transports moisture towards the west coast during the southwest monsoon. Both weak low-level jet and developing El Nino conditions has led to a weakened southwest monsoon and suppressed monsoon activity over south peninsular India. In addition, the developing El Nino is also causing large-scale sinking of air over southern India, suppressing cloud formation and enhancing daytime heating. “The low-level jet is currently weak, reducing moisture transport and weakening the southwest monsoon over the west coast. With fewer monsoon clouds and little rainfall, interior Tamil Nadu is experiencing clear skies and intense daytime heating,” Durai said. Durai said the low-level jet, presently gusting around 40kmph, is expected to strengthen to nearly 100kmph by Friday, increasing moisture transport and improving rainfall activity across the state.“The stronger winds may bring widespread light rainfall over Tamil Nadu from Friday. This phase may last about a week before weakening again,” he said.IMD has forecast heatwave conditions at isolated places over interior Tamil Nadu on Wednesday. While light rain is likely over isolated Western Ghats districts, the rest of the state is expected to remain largely dry.On Tuesday, several districts recorded temperatures well above normal. Vellore recorded 40.4°C (5.4 degrees above normal), Tiruttani 40.5°C (5.3 degrees above normal), Trichy Airport 40.1°C (3.8 degrees above normal) and Palayamkottai 40.1°C (5.6 degrees above normal). Chennai was also unusually hot, with Nungambakkam and Meenambakkam recording 39°C and 39.4°C, around 3.6 and 3.8 degrees above normal. “Dry northwesterly winds and clear skies are making the weather feel more like May than July,” said blogger Pradeep John. “Relief is likely from Friday as weather models indicate more widespread rainfall.” Since June 1, Tamil Nadu has recorded 86.5mm rainfall, around 11% above normal. Tirunelveli has recorded the highest rain so far with 259.1mm, around 784% above normal. Chennai has recorded 70.1mm, around 34% below normal.
