El Nino to return in September, but won’t affect monsoon
New Delhi: The El-Nino weather phenomenon, which can create drought-like conditions, is expected in September this year, but is not likely to have much effect as it would appear towards the end of the monsoon season in India, a meteorological department official said.
El Nino is declared when temperatures deviate by 0.5°C above normal in the equatorial Pacific Ocean. According to the India Meteorological Department (IMD), until the end of August, neutral conditions will continue, with temperatures remaining -0.5°C below normal and 0.5°C above normal. Thereafter, a weak El Nino will start evolving and temperatures will start rising, IMD said. But the weather pattern will be felt only at the end of September and will therefore not affect India’s south-west monsoon, it said.
The accuracy of this forecast is limited, cautioned A.K. Sahai, head of climate research and services at IMD, Pune. “It is too far from now to provide predictions and it is only in the month of April that we can give authentic prediction,” Sahai said.
The US-based National Oceanic and Atmospheric Administration (NOAA), in its latest bulletin dated 9 February, declared that La Nina, which is a cooling of the waters, has ended and that sea surface temperatures in the tropical Pacific Ocean have returned towards normal.
El Nino and La Nina are atmospheric changes associated with the warming and cooling of the Pacific Ocean. While El Nino is associated with the droughts in India, La Nina is associated with excess rainfall.
Last month, the Japan Agency for Marine Earth Science and Technology also predicted a weak El Nino occurring in the second half of 2017, but said at the same time the positive Indian Ocean Dipole (IOD) may set in, which would neutralize the bad effect of the weak El Nino in far away Pacific Ocean, leading to a good south-west monsoon in India.
The south-west monsoon in India is affected by five parameters including El Nino, La Nina and IOD.
During El Nino years, the south-west monsoon brings poor rains in India but the north-east monsoon brings normal or above normal rain. Severe El Nino conditions last occurred in 2014 when the country received 12% excess rain in the northeast monsoon season and 22% less than normal rain during the south-west monsoon.