Nights warm as cloud cover, humidity Persist

Chennai: While daytime temperatures continue to fluctuate between below and above normal, nights have remained consistently warmer over the past several days.On Monday, Nungambakkam and Meenambakkam recorded minimum temperatures of 28.5°C and 28.1°C, around 1.3 degrees above normal, just before sunrise.

They later recorded 38.6°C and 38.7°C respectively, around 2.6 degrees above normal.Meteorologists said the cloud cover associated with the depression over the northwest Bay of Bengal spread over the city and high atmospheric moisture reduced the escape of heat absorbed by land during the day, keeping nights warmer than usual. The high humidity also increased the ‘feels-like’ temperature, causing discomfort.“On Tuesday, the city and the suburbs may receive light rainfall. The sky may remain partly cloudy with maximum temperatures of 37°C-38°C and minimum temperatures of 28°C-29°C,” an IMD bulletin said.Private forecasters said warm nights are likely to continue until the weather system over the Bay weakens or moves inland.“Clouds and water vapour act like a blanket by absorbing part of the heat radiated from the Earth’s surface and sending some of it back.

This slows nighttime cooling, keeping minimum temperatures above normal. We expect this pattern to continue for another four to five days, though there is no significant rain activity expected,” said Mahesh Palawat, chief meteorologist, Skymet Weather.Blogger Pradeep John said persistent westerly winds and the delayed or weak sea breeze have contributed to the recent rise in daytime temperatures. “Warm nights may continue until the depression over the Bay moves inland,” he said.The India Meteorological Department has forecast maximum temperatures to remain around 2 degrees above normal in isolated places across Tamil Nadu on Tuesday. Rainfall is likely to be confined to isolated parts of the Western Ghats, with light to moderate showers.