Indian monsoon may be hit by El Nino in second half; IMD on alert for super event

New Delhi: The second half of the Indian summer monsoon may be impacted by a moderate or strong El Nino, but it is a bit early to figure out if the warming of the Pacific will develop into a 'super El Nino', influencing weather even in 2027, meteorologists said here on Thursday.

Nevertheless, Indian weather scientists will keep a close watch, particularly in the wake of the latest modelling results from European Centre for Medium Range Weather Forecast suggesting 98% chance of a moderate El Nino by August; 80% possibility of a strong event and 22% chance of a super El Nino.

El Nino is a natural cyclical warming of several of the parts Pacific Ocean, altering weather patterns across the globe. El Nino years are generally associated with poor monsoon in India but there are exceptions.

“All the models are in agreement of El Nino development in the second half of the monsoon season and the transition is expected by August. But at this time, the models are not very accurate in forecasting the El Nino strength due to spring barrier,” Mrutyunjay Mohapatra, director general of meteorology at India Meteorological Department told DH.

The spring barrier refers to uncertainty in the outlook for ENSO (the El Nino – Southern Oscillation, as the phenomenon is known) in the first half of the year. It conveys the general idea that ENSO forecasts are more uncertain, or less skillful, in the spring season in the Northern Hemisphere.

Indian meteorologists said a clearer picture on a super El Nino might emerge by the end of May.

In a super El Nino, the sea surface temperature rises by two degrees Celsius whereas in the case of a strong event, the temperature rise is more than 1.5 degrees Celsius. A moderate El Nino is marked by a temperature rise of 1-1.5 degrees Celsius.

The World Meteorological Organisation in its February update said the likelihood of El Nino developing increases steadily, rising to around 30% in April–June and 40% in May–July. The ENSO neutral conditions are likely to persist in early summer.

A similar forecast has come from the USA’s National Oceanic and Atmospheric Administration that predicts 56% chance of ENSO-neutral condition between June and August, 2026 and nearly 60% chance of El Nino developing by August-September.

“Its too early to make a forecast about a super El Nino but we will have to closely monitor the situation. In 1997 we had a good monsoon even though it was super El Nino year. The models are currently showing a rise of one degree Celsius by the second half of the monsoon, but we have to wait till May for a clear picture,” said veteran weather scientist M Rajeevan, former Secretary in the Union Ministry of Earth Sciences.

“But if a super El Nino develops, I will be worried more about the heat waves in 2027. A harsh summer will set in early,” Rajeevan added.