The chances of the El Nino phenomenon impacting the South West monsoon at its peak across India are 60 to 70 per cent, says Weather Risk Management Services (WRMS).
El Nino, which refers to the formation of warm water undercurrents in the Pacific Ocean, has been known to have an adverse effect on global weather patterns and occasionally affect the rainfall during the Indian monsoon season.
At the same time, another important parameter, called the Indian Ocean Dipole, is predicted to evolve towards a warm phase, which normally bestows a positive effect on the monsoon.
In view of these mixed developments, the monsoon rainfall during 2017 could be moderately on the negative side of the long-period range.
Giving these details to the media, Kanti Prasad, Head of Meteorological Services at the New Delhi-based WRMS and former technical director of the India Meteorological Department (IMD), said, “Large parts of North India, particularly North West India, may experience deficiency in overall precipitation, whereas the southern regions are expected to receive normal to excess rainfall”.
He was participating in a WRMS-organised seminar on ‘Insurance for covering seed germination and production risks’. The interpretation is based on information available from prominent World Climate Centres, the Climate Forecast System model, which the organisation uses to provide climate change-related risk management services, including weather forecasts in 15 countries, a press release said.
The impact of El nino on Monsoon rainfall could be in the later phase or late August-September.The monsoon will arrive near its expected date on June 1 over India and its distribution will be good helping sowing operations, Prasad said.
By mid-April 2017, the tropical Pacific remained in an El Nino Southern Oscillation (ENSO-neutral state), with above-average SSTs (sea surface temperatures) in the eastern Pacific Ocean, and near-average SSTs across the central and east-central part of the basin. The warm ocean temperature is gradually spreading westward, he added.
In mid-April, the IMD had in its annual forecast of the Long Range Forecast for Monsoon 2017 said the country will receive normal rains during the SW monsoon run between June 1 to September 30. The weather office said the rainfall will be 96 per of the long-period average (LPA), with a 38 per cent probability that monsoon will be near normal.
The IMD and a couple of private weather forecasters have developed medium-range forecasts of 15-45 days’ periodicity, which will offer more reliable region-wise rainfall forecasts, said Sonu Agrawal Founder of WRMS.