Weak El Nino likely to shadow south-west monsoon till August: WMO.

• El Nino is linked to below normal rainfall and droughts during south-west monsoon in India

• The IMD, too in its April forecast had indicated that weak El Nino conditions could impact the monsoon during the first half

As the development of the southwest monsoon remains sluggish over the Andaman Sea, a latest update by the World Meteorological Organization (WMO) has reaffirmed that weak El Nino conditions would persist during June to August, the initial period of monsoon season.

A naturally occurring phenomenon, El Nino has a major influence on weather and climate patterns over many parts of the world and is linked to below normal rainfall and droughts during south-west monsoon in India.

The global organization stated on Monday that sea surface temperatures in the tropical Pacific Ocean have been at borderline to weak El Niño levels in April and early May and are predicted to remain close to current levels through the June-August period, which includes three of the four months of the monsoon rainfall.

The conditions may ease during September-November and El Nino could further reduce its intensity or even turn neutral. The India Meteorological Department (IMD), too in its April forecast had indicated that weak El Nino conditions could impact the monsoon during the first half.

“The situation regarding El Nino has not changed much. It remains weak, as we predicted in April. We could see some impact in the first half of monsoon," said Dr D S Pai, senior scientist, IMD.

Meanwhile, the south-west monsoon which reached the Andaman and Nicobar Islands on May 18 has not been able to make significant advancement, due to unfavorable cross-equatorial flow. According to IMD, it would further be able to advance into some more parts of south Bay of Bengal, Andaman Islands and north Andaman Sea during May 29-30.

“Monsoon is weak, it is not organizing. After reaching Andaman Sea, it got weakened, so it needs some support. If mid-latitude activity is strong, then slowly it would begin to strengthen and we would be able to see some progress," said Dr Pai.

The rainfall during the four month monsoon period is extremely crucial for the agrarian economy of the country, as it irrigates half of India’s crop land. Over 75% of the annual rainfall is received during this period.

WMO has however assuaged concerns over the potentially serious impact of El Nino stating that a strong El Nino appears unlikely. "Even if ocean conditions do remain at El Niño levels for the next several months, the chance for a strong event (sea surface temperatures in the east-central tropical Pacific rising to at least 1.5°C above average) during this period is low," stated WMO.

2016 became the warmest year on record because of a powerful El Niño in 2015-2016 combined with long-term climate change. Climate change has increased air and sea surface temperatures and also ocean heat.

Even though El Nino would begin to weaken after September, the development of its opposing phase, called La Niña is extremely unlikely, said WMO in its latest update released on Monday.

The monsoon is likely to make a delayed onset over the Kerala coast on June 6, as per IMD.(Source: Livemint)