India Poised To Experience Driest August Since 1901 Amid Intensifying El Nino

Another reason for August being a below-normal rainfall month is the "unfavourable phase of the Madden Julian Oscillation.

August is expected to be the driest since 1901 amid intensifying El Nino/Representational Image

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India is poised to experience the driest August since 1901 as a clear result of intensifying El Nino conditions according to senior meteorologists. This year’s monsoon is also expected to be the driest since 2015, which recorded a rainfall deficit of 13 per cent, they said, as per a PTI report. The primary reason for below-normal rainfall in August was El Nino, as per India Meteorological Department chief Mrutyunjay Mohapatra. El Nino refers to the warming of waters in the Pacific Ocean near South America and is generally associated with weakening monsoon winds and dry weather in India. 

Another reason for August being a below-normal rainfall month is the "unfavourable phase of the Madden Julian Oscillation (MJO) which is known to reduce convection in the Bay of Bengal and the Arabian Sea", according to Mohapatra. 

The MJO is a large-scale intraseasonal atmospheric disturbance originating in tropical Africa and travelling eastwards. 

The active phase of MJO enables a favourable atmosphere for rainfall which leads to increased cloud cover, stronger winds, and enhanced active connective activity, resulting in heavier rainfall over the Indian subcontinent. 

"The favourable phase of MJO results in rainfall even if there is no low-pressure system. July recorded above-normal rainfall due to the favourable phase of MJO," Mohapatra said, according to the report. 

Only two low-pressure systems developed over the Bay of Bengal (BoB) against a normal of five under the impact of the prevailing El Nino conditions, he said. "Another reason for below-normal rainfall in August was a lower number of low-pressure systems in the South China Sea and they, too, moved northward," he said.

However, due to positive Indian Ocean Dipole, the outlook for September is not very bleak, Madhavan Rajeevan, former secretary at the Ministry of Earth Sciences, told the news agency.