New Delhi: Weak El Niño conditions would persist from June through August, the World Meteorological Organization (WMO) reaffirmed on Monday. The prediction comes at a time when the southwest monsoon remains sluggish over the Andaman Sea.
El Niño, a naturally occurring phenomenon, has a major influence on weather and climate patterns over many parts of the world. For India, it is linked to below normal rainfall and droughts during the southwest monsoon. The specialized United Nations agency said sea surface temperatures in the tropical Pacific Ocean have been at the borderline to weak El Niño levels in April and early May. It predicted that the conditions will remain close to current levels from June to August, or three of the four months of the monsoon.
The conditions may ease in September-November, and El Niño could further reduce its intensity or even turn neutral. The India Meteorological Department (IMD) had in its April forecast indicated that weak El Niño conditions could affect the monsoon in the first half.
“The situation regarding El Niño has not changed much. It remains weak, as we predicted in April. We could see some impact in the first half of the monsoon," said D.S. Pai, senior scientist, IMD. The southwest monsoon, which reached the Andaman and Nicobar Islands on 18 May, is yet to gather momentum because of unfavourable cross-equatorial flow. It is likely to further advance to south Bay of Bengal, Andaman Islands and north Andaman Sea on 29-30 May, according to the IMD.
“The monsoon is weak. After reaching the Andaman Sea, it got weakened, so it needs some support. If mid-latitude activity is strong, then it would slowly begin to strengthen and we will be able to see some progress," said Pai.
The rainfall during the four-month monsoon is extremely crucial for India’s agrarian economy, as it irrigates about half of the cultivated land. More than 75% of the annual rainfall is received during this period.
The WMO has, however, assuaged concerns over the potentially serious impact of El Niño, saying that a strong El Niño appears unlikely. “Even if ocean conditions do remain at El Niño levels for several months, the chance of 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," it said.
The warmest year on record was 2016, which was a result of a powerful El Niño in 2015-2016 combined with long-term climate change, which has increased air and sea surface temperatures, besides ocean heat. El Niño will start weakening after September, but the development of its opposing phase, La Niña, is extremely unlikely, said WMO in its latest update. The monsoon is likely to make a delayed onset over the Kerala coast on 6 June, according to the IMD.