The India Meteorological Department (IMD) has revised its seasonal rainfall forecast downward, predicting a 90% chance of below-normal rainfall, with a 60% probability of a deficient season.
The forecast, which carries a model error of ±4%, marks the lowest monsoon season rainfall in 11 years, with the June-to-September season expected to receive only 87cm of rainfall, 3cm less than the long-period average.
The IMD has attributed the revision to the early onset of El Niño, which is expected to develop during the monsoon season, and the disappearance of the Indian Ocean Dipole buffer, which can partially offset El Niño's suppressive effect on the monsoon.
The agency has warned that below-normal rainfall may lead to challenges for agriculture, water availability, hydropower generation, and ecosystem sustainability, with increased risks of drought, heat stress, and pressure on drinking water resources.
The central estimate of 90% sits at the deficient threshold, and officials have cautioned that the forecast probability is not the only factor, with dynamic factors also being considered.
The IMD has also projected below-normal rainfall for the country as a whole in June, with the sharpest deficit forecast for Northwest India, and the Monsoon Core Zone facing a similar below-normal outcome.
The onset of the monsoon is now in doubt, with the IMD's extended range forecast showing largely dry conditions over Kerala between May 28 and June 4, with only a marginal improvement between June 4 and June 11.
June will also be hotter than previously estimated, with above-normal heatwave days expected over many parts of the country, and below-normal heatwave days expected in Rajasthan and Jharkhand.
