Large parts of northern and central India were in the grip of extreme heatwave conditions on Tuesday with the mercury crossing 50 degrees Celsius in Rajasthan's Churu and Haryana's Sirsa and settling nine notches above normal in Delhi.

At least three weather stations in Delhi recorded maximum temperatures of 49 degrees Celsius or more. Mungeshpur and Narela in Delhi clocked 49.9 degrees followed by Najafgarh at 49.8 degrees Celsius, the India Meteorological Department (IMD) said.

This was the highest maximum temperature recorded in the capital this season. However, Mungeshpur and Narela weather stations came up in 2022 and have records only for the last three years.

The IMD said respite from the heatwave conditions could be in sight after May 30.

It said that a fresh western disturbance was expected over parts of northwest India on Thursday which could bring isolated rainfall over the region on the weekend.

IMD Director General Mrutyunjay Mohapatra has attributed the heatwave conditions over northwest and central India to the absence of western disturbances during the latter half of May.

Western disturbances are extra-tropical weather systems formed over the Mediterranean Sea that move from the west to the east.

According to the IMD, 10 weather stations recorded the highest-ever maximum temperature and the highest for the month -- Agra-Taj (48.6 degrees Celsius), Dehri in Bihar (47 degrees Celsius), Hamirpur in Uttar Pradesh (48.2 degrees Celsius), Jhansi in Uttar Pradesh (49 degrees Celsius), Narnaul in Haryana (48.5 degrees Celsius), Ayanagar-Delhi (47.6 degrees Celsius), New Delhi-Ridge (47.5 degrees Celsius), Rewa in Madhya Pradesh (48.2 degrees Celsius), Rohtak in Haryana (48.1 degrees Celsius), and Varanasi in Uttar Pradesh (47.2 degrees Celsius).

In some much-needed relief, south Rajasthan districts of Barmer, Jodhpur, Udaipur, Sirohi and Jalore recorded a drop in temperatures up to four notches on Tuesday due to moist wind incursion from the Arabian Sea, indicating the beginning of abatement of heatwave conditions over northwest India.

Numerical weather prediction models showed that this decreasing trend would further extend northwards, bringing gradual respite from heatwave conditions from May 30 onwards.

Also, the incursion of moist winds from the Bay of Bengal from Wednesday onwards is likely to result in a gradual fall in maximum temperatures over Uttar Pradesh from May 30, the IMD said.

"Today, heatwave to severe heatwave conditions prevailed over most parts of Rajasthan, Haryana-Chandigarh-Delhi, in many parts of Uttar Pradesh, Madhya Pradesh and in isolated pockets of Bihar and Himachal Pradesh," it said.

It said that heatwave conditions also prevailed in many places over Vidarbha, in some pockets over Jammu and Kashmir and in isolated pockets of Uttarakhand and Chhattisgarh.

Churu in Rajasthan was the hottest place in the country with a maximum temperature of 50.5 degrees Celsius, followed by Sirsa-AWS in Haryana (50.3 degrees Celsius), Mungeshpur and Narela (49.9 degrees Celsius), Najafgarh (49.8 degrees Celsius), Sirsa (49.5 degrees Celsius), Ganganagar in Rajasthan (49.4 degrees Celsius), Pilani and Phalodi in Rajasthan and Jhansi (49 degrees Celsius).

Warm night conditions in isolated pockets are very likely to prevail over Uttar Pradesh, east Madhya Pradesh, Punjab, Haryana, Chandigarh and Delhi over the next few days, the weather office said.

The scorching heat prompted the Haryana government to advance summer vacations in all state-run and private schools to Tuesday.

The deadly heatwave is testing power grids and leading to water shortages in parts of the country.

According to the Central Water Commission, water storage in 150 major reservoirs in India dropped to just 24 per cent of their live storage last week, exacerbating water shortages in many states and significantly affecting hydropower generation.

The Maharashtra irrigation department said that the water stock in Jayakwadi dam in the drought-prone Marathwada region stood at a mere 5.19 per cent of its capacity on Monday after recording an evaporation loss of 1.15 MCM (million cubic metres) in a single day due to the heat.

The intense heat has already driven India's power demand to 239.96 gigawatts, the highest so far this season, with air conditioners and coolers in homes and offices running at full capacity.

Experts anticipate that power demand could rise even further and surpass the all-time high of 243.27 GW recorded in September 2023.

Severe heatwaves have impacted a large number of people in parts of India for three consecutive years, affecting health, water availability, agriculture, power generation, and other sectors of the economy.

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