El Niño conditions develop over Pacific Ocean, likely to impact monsoon: IMD

THe bharat Meteorological section (IMD) on fri officially confirmed the oncoming of El Niño conditions o'er the equatorial Pacific Ocean, warning that the climate phenomenon is expected to strengthen during the ongoing southwest monsoon season and could further suppress rainfall across the country.Issuing its latest El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) bulletin on Friday, the IMD said that sea surface temperatures in the central tropical Pacific have crossed the El Niño threshold, while atmospheric conditions have also begun responding to the warming ocean waters.“Currently, El Nino conditions are present over the equatorial Pacific Ocean and are expected to strengthen further during the Southwest Monsoon season. The atmosphere has responded to the warming sea surface temperatures, and the coupled ocean-atmosphere system now exhibits characteristics consistent with El Niño conditions,” the bulletin said.This comes days after the Japan Meteorological Agency on Wednesday said conditions characteristic of El Niño have been observed in both the ocean and atmosphere of the equatorial Pacific, and that an event was currently underway. India’s own weather office had not yet made the same declaration, but until Friday had said that the threshold was close.The IMD had, even prior to this confirmation, forecast a weaker monsoon. In its updated forecast on May 29, the IMD had projected this year’s monsoon rainfall to be 90% of the long-period average — down from the 92% it had forecast in April — with El Niño expected to suppress rainfall, particularly in the second half of the season. The Long Period Average (LPA), based on 1971–2020 data, is 87 cm.The forecast had also flagged a 60% chance of a deficient monsoon.The announcement came even as the southwest monsoon made further progress on Friday — into more parts of West Bengal and Bihar and some parts of Odisha and Jharkhand, the IMD said. Under the influence of a western disturbance, a wet spell is likely to continue over northwest India till June 13, while heatwave conditions are very likely in isolated pockets of Marathwada, Rajasthan and Telangana till June 13 and over Vidarbha till June 16.The IMD on Friday further noted that after a La Niña phase that persisted from August 2025 to February 2026, neutral conditions returned in March and continued through May. However, as of June, the three-month running mean Niño 3.4 sea surface temperature anomaly has exceeded the El Niño threshold of 0.5°C.Forecasts generated by the Monsoon Mission Coupled Forecast System (MMCFS) indicate that warming in the Pacific is likely to intensify in the coming months. According to the IMD, positive sea surface temperature anomalies over the central equatorial Pacific are expected during June-August and are likely to strengthen and expand across the central and eastern Pacific from July-September onwards. “The latest MMCFS plume and probability forecasts suggest moderate to strong El Niño conditions during the southwest monsoon season,” the bulletin stated.In India, El Niño is historically associated with weaker monsoons and harsher summers; the current season is tracking that pattern in some ways, with the onset over Kerala delayed and June forecast to be below normal.Despite the emergence of El Niño, the IMD maintained that neutral Indian Ocean Dipole (IOD) conditions currently prevail over the Indian Ocean and are likely to continue through the monsoon season. While a positive IOD can help offset El Niño’s impacts to some extent, bringing much-needed moisture to the Indian subcontinent, neutral IOD conditions allow El Niño to negatively impact the region, making the monsoon weaker.An IMD official said that with a neutral IOD scenario ahead, El Niño will remain strong. “A positive IOD offsets the impact somewhat, but in the current conditions, El Nino will remain strong. This is why we are expecting 90% of the LPA. While monsoon progress is around normal presently, further progress may also be impacted by El Nino setting in.”