Temperatures to soar across Tamil Nadu from today

Weather Update

Among the weather bloggers of Chennai it is often remarked while there is always a hint of doubt about the monsoons, be it Southwest or Northeast, at times we might feel the pre monsoon thunderstorm season also might fail, but the bullet proof season without a hint of failure is the summer season which almost always arrives right on cue. Yesterday Karur Paramathi became the first IMD station in Tamil Nadu to record the first 40ºC of the year.

This year though if one looks at the overall picture of Indian Sub Continent it appears Summer 2021 has possibly arrived earlier than expected with Delhi recording its first 40ºC in more than 75 years during the month of March. Churu in Rajasthan recorded 43.3ºC which is the highest recorded temperature during the month of March for the station. Similarly Barmer recorded 42.8ºC on Sunday which is just 0.5ºC off the highest recorded temperature for Barmer during the month of May. Similarly Brahmapuri in Vidharba recorded 43.3ºC yesterday well above the highest recorded temperature during the month of March.

With weather models indicating westerlies to strengthen over Peninsular India, interior Tamil Nadu, particularly the seasonal summer heavyweights like Tiruttani are now getting ready to join the summer bandwagon. Few models indicate later part of this week to see winds from the Northwest which is likely to create heat wave like conditions across most of North TN & parts of Interior TN.

In this context it is pertinent to once again remind how IMD classifies Heatwave. Heat wave is considered if maximum temperature of a station reaches at least 40ºC or more for Plains and at least 30ºC or more for Hilly regions along with a departure from average temperature between 4.5ºC & 6.5ºC, while severe heatwave is declared if departure is above 6.5ºC. Irrespective of the departure from average heat wave is declared if the absolute maximum temperatures of 45ºC is recorded in at least two stations in a subdivision & severe heat wave is declared if absolute maximum temperature exceeds 47.5ºC.