CHENNAI: It was the first active rainy day this summer for Chennaiites. The city witnessed a sudden shift in weather pattern and the mercury level plummeted 15 degrees post-afternoon with a sharp spell of rainfall. About 30 mm of rainfall poured in within just 15 minutes, around 1.30 pm.
All southern parts of the city received good rainfall. Taramani recorded 51 mm. After December last, this was the first noticeable rainfall numbered, although some sporadic rainfall was witnessed in March.
Incidentally, the Meenambakkam weather station near the Chennai airport recorded the highest temperature in the State on Wednesday, clocking 40.1 degrees Celsius and Nungambakkam recorded 39 degrees, which is 2.2 and 1.5 degrees above normal.
This intense heating of the surface caused the rainfall, which is also characterised as a convectional rainfall. “The sun heats the ground and water evaporates. As water vapour rises, it cools. When water vapour cools, it condenses and forms droplets. These droplets form clouds and fall to the earth as rain. On Wednesday, the conditions fell in place perfectly. The humidity was as high as 90%,” met officials said.
Noted weather blogger Pradeep John said similar conditions are likely to prevail on Thursday as well. From Friday, the rainfall activity will fizzle out as the Southwest monsoon would peak along the West Coast. The Western Ghats region would start receiving good rainfall. Some of the other parts that received good rainfall are Cheyyur (70 mm), Hindustan University (40 mm), Sathyabhama University (36 mm) and Puzhal (34 mm).