Bhubaneswar, April 13: The India Meteorological Department on Monday predicted that the southwest monsoon seasonal (June to September) rainfall over the country is most likely to be below normal (95-90% of the Long Period Average (LPA) this year.
It predicted that the seasonal rainfall over the country is likely to be 92% of LPA with a model error of ± 5% while the LPA of the seasonal rainfall over the country based on the period of 1971-2020 is 87 cm.
The forecast based on both dynamical and statistical models suggests that quantitatively, the monsoon seasonal rainfall is likely to be 92% of the Long Period Average (LPA) with a model error of ± 5%. The LPA of the seasonal rainfall over the country for the period 1971-2020 is 87 cm.
The five-category probability forecast for the Seasonal (June to September) rainfall over the country is given below. The forecast indicates that the probabilities for both below normal and deficient rainfall categories are higher than their respective climatological probabilities. The forecast probabilities for the “Above Normal” and “Excess” rainfall categories are lower than their respective climatological probabilities. Overall, the Southwest Monsoon seasonal rainfall over the country is most likely to be below normal (90–95% of LPA).
The MME forecast for the 2026 southwest monsoon seasonal rainfall was prepared based on the April initial conditions and using a group of coupled climate models that having highest prediction skill over the Indian monsoon region.
The spatial distribution of probabilistic forecasts for tercile categories (above normal, normal, and below normal) for the seasonal rainfall (June to September) is shown in Fig.1. The spatial distribution suggests that the below-normal seasonal rainfall is most likely over many parts of the country except some areas over Northeast, Northwest, and South Peninsular India, where normal to above-normal rainfall is likely. The white-shaded areas within the land area represent no signal from the model.
At present, Weak La Niña–like conditions are transitioning to ENSO-neutral conditions over the equatorial Pacific. However, some atmospheric circulation features across the tropical Pacific remain consistent with weak La Niña–like conditions. The latest forecasts from the Monsoon Mission Climate Forecast System (MMCFS) suggest that ENSO-neutral conditions are most likely to continue during the April to June 2026 season. The Monsoon Mission Climate Forecast System (MMCFS) suggests the development of El Niño conditions during the SW Monsoon season.
Currently, neutral Indian Ocean Dipole (IOD) conditions are present over the Indian Ocean and the latest Climate models forecast indicates that the positive IOD conditions are likely to develop towards the end of the southwest monsoon season.
As sea surface temperature (SST) conditions over the Pacific and the Indian Oceans are known to have a strong influence on the Indian monsoon, IMD is carefully monitoring the evolution of sea surface conditions over these Ocean basins.
The northern hemisphere snow cover extent during the last three months (January to March 2026) was slightly below normal. Winter and spring snow cover extent over Northern Hemisphere as well as Eurasia has a general inverse relationship with the subsequent southwest monsoon seasonal rainfall over the country.
