Why it is so hot almost everywhere in India

Why it is so hot almost everywhere in India

Subject: Environment

Context- THE INDIA Meteorological Department (IMD) on Wednesday forecast heatwave conditions over East, Central & Northwest India during the next five days, and issued a yellow alert (“watch, be updated”) for the entire country except Uttarakhand, Tamil Nadu, Andhra Pradesh and parts of the Northeast for Thursday.

Concept-

• Severe heat conditions have prevailed over large parts of India almost consistently since the beginning of March, and maximum temperatures in west Rajasthan and Vidarbha in Maharashtra have stayed between 40°C and 45°C throughout the last two months.
• March this year was the third hottest since 1901, with the average maximum temperature at 32.65°C against the normal of 31.24°C, the IMD said.
• The country has seen four heatwaves including one that is currently ongoing, and 26 heatwave days since the beginning of March.

Why is this happening?

• It is essentially due to the fact that the normal periodic light-intensity rainfall, hail, and lightning have remained absent over most areas of the country.
• The rainfall deviation from normal for the country as a whole was negative 70.7 per cent in March (8.9 mm instead of the normal 30.4 mm), according to IMD data.
  • A total 231 out of 695 districts (33%) received no rain between March 1 and April 27, and in another 298 districts (43%) rain was deficient or ‘large deficient’.
• Western Disturbances:
  • The western disturbances have not been sufficiently strong this summer,
  • Normally, passing western disturbances— eastward propagating windstreams that originate above the Mediterranean Sea — interact with moist winds from southern India to trigger thunderstorms (nor’west- ers).
  • The intermittent light rain and thunder puts a check on the heat.