Amid several researched-based reports indicating that a scorching summer can subdue the spread of coronavirus outbreak, the India Meteorological Department (IMD) has said that the summer season will see more heat wave events and will be hotter than normal summer this year.
According to the IMD, the average maximum temperature is likely to be warmer than normal by 0.5 degree Celsius to 1 degree Celsius in April, May and June in over east and west Rajasthan, west Madhya Pradesh, Gujarat, Konkan and Goa, Madhya Maharashtra, Marathawada, north and south interior Karnataka, coastal Karnataka, Rayalaseema and Kerala.s
The rest of the country is likely to experience normal maximum temperatures (Departure from normal within - (minus) 0.5 degree Celsius and 0.5 degree Celsius).
Average seasonal temperatures of 1°C above normal can mean a rise of several degrees above normal on extremely hot days of the season.
“There is also about 40 per cent probability of maximum temperatures in the core heat wave zone (CHZ) during April to June 2020 to be above normal. The CHZ spans over Punjab, Himachal Pradesh, Uttarakhand, Delhi, Haryana, Rajasthan Uttar Pradesh, Gujarat, Madhya Pradesh, Chhattisgarh, Bihar, Jharkhand, West Bengal, Odisha, Telangana and meteorological sub-divisions of Madhya Maharashtra, Marathwada and coastal Andhra Pradesh.
This in turn suggests that slightly above normal frequency of heat wave conditions likely in the core HW zone during the season.
According to IMD, a heat wave is recorded when the maximum temperature is 4-5 degrees Celsius above normal in regions where the normal maximum temperature is more than 40 degrees; and 5-6 degrees above normal where the normal maximum temperature is less that 40 degrees. A heat wave is also declared when the actual maximum temperature remains above 45 degrees Celsius at any place irrespective of its normal maximum temperature.
During this year’s summer, the average minimum would be over 1 degree Celsius from normal. Warmer nights have been forecast over Rajasthan, Delhi, Haryana, Punjab, Odisha, Jharkhand and some parts of central India during the next three months.
According to the latest weather model inputs, the El Nino Southern Oscillation condition continues to remain in neutral phase and it shall continue to remain so, till the end of June, stated the seasonal forecast.
Whenever there is El Nino condition - that is abnormal warming observed along the equatorial Pacific Ocean - the global temperatures are high. This warming also interferes with rainfall during the Indian southwest monsoon.
According to the IMD study, five States which include Uttar Pradesh, Bihar, West Bengal, Meghalaya and Nagaland have shown significant decreasing trends in southwest monsoon rainfall during the recent 30 years period (1989-2018) while the other States do not show any significant changes in southwest monsoon rainfall during the same period. "The maximum monsoon seasonal rainfall is reported over Goa State with 2878.0 mm followed by 2702.4 mm over Meghalaya. Similarly, the lowest monsoon rainfall of 311.7 mm is reported over Tamil Nadu followed by 414.2 mm over Rajasthan. Over major states of central India, the mean rainfall ranges from 800 mm to 1400 mm." it said.
