Impact of El Nino to be clear by May-end

Senior IMD officials say the phenomenon causing less rain during monsoon has now become neutral

Ahead of the official monsoon forecast on Thursday, the dreaded El Nino phenomenon and its devastating impact on Indian rains has once again become a point of discussion.

Senior India Meteorological Department (IMD) officials said El Nino, known to cause less rains, has now become neutral.

“This is the post-spring season for the El Nino and the neutral conditions would continue till the middle or the later part of May. Whether or not the El-Nino has an impact on the later stages of the four-month southwest monsoon, would only be known by end-May,” said a senior IMD official involved in the process of preparing the annual forecast.

The official said the current spell of low rains in northern India would not have an impact on the onset and distribution of southwest monsoon over the region. “The western disturbances this year have been more than those in the previous year, but how far that would impact the onset of monsoon over the region can’t be said now. It all depends on the timing of these western disturbances. Sometimes, these aid monsoon activity, sometimes these don’t,” the official said.

The uncertainty over India’s southwest monsoon was first highlighted by an adverse prediction by the Japan Agency for Marine-Earth Science and Technology and the International Research Institute for Climate and Society at Columbia University. These had said there were little chances of India getting above-normal monsoon this year.

The United Kingdom’s meteorological office, in its long-range global weather forecast, had said the chance of India getting above-normal rainfall during the July-September period was only 40 per cent.

“Both the predictions were brought out in January and February, too early to make any accurate assumption,” the official said.

These forecasts were in complete variance with the prediction by the Pune-based Indian Institute of Tropical Meteorology in April. The institute had said the experimental dynamical model showed the monsoon was more likely to be on the positive side of normal, though a weak El Nino might develop in the later part of the season. Later, the director-general of IMD, L S Rathore, told Reuters news agency that this year, rains could be normal, owing to the absence of any strong signal that could inhibit the occurrence of a healthy monsoon.

According to IMD’s classification, rains between 96 and 104 per cent of a 50-year average of 89 centimetres are considered normal. The last drought, with rains below this range, was in 2009, and the one before that in 2004.

Though the Union agriculture ministry has said the southwest monsoon could be normal this year, food department official have been cautious.

At a meeting of the South Asia Climate Outlook Forum (Sascof) in Pune earlier this month, it was said the northwest and southern parts of the Indian sub-continent could receive below-normal rains this year. “Though the consensus outlook indicates the summer monsoon rainfall for the entire South Asian region is likely to be within the normal range, there is also a slight tendency for the rainfall to be below normal,” the forum had said in its report. It added there was a likelihood of below-normal rains over some areas of northwestern and southern parts of South Asia.

The areas Sascof said were likely to receive below-normal rains this year included India’s primary foodgrain-growing regions of Punjab, Haryana, western Uttar Pradesh and parts of Tamil Nadu, Kerala and Karnataka.

“The Sascof predictions are the best possible scenarios, given these are made by member countries like Pakistan, Bangladesh and India,” the IMD official said, adding some weather models were indeed suggesting below-normal rains in the northwestern and southern parts of the country.

The four-month southwest monsoon season starting June is crucial not only for Indian agriculture, but also for the general economy.