IMD predicts normal Monsoon rains for 2023 amidst evolving El Nino

India’s nodal agency, India Meteorological Department (IMD) has predicted normal Monsoon rains for the country for the fifth consecutive year. According to IMD, Monsoon 2023 is likely to record normal rains to the tune of 96% of the long period average (LPA), with an error margin of +/-5%.

As per the models, the southwest monsoon seasonal (June to September) rainfall over the country, is likely to be normal with highest probability of 35% against the climatological probability of 33%. 

Image Credit: IMD

Talking region-wise, several areas of Peninsular India and adjoining East Central India, East India, Northeast India and over some parts of Northwest India are likely to witness normal rainfall. However, some areas of Northwest India and parts of west-central India and some pockets of Northeast India are most likely to record normal to below normal rainfall is likely over.

Image Credit: IMD

Factors Impacting Southwest Monsoon 2023

El Niño: Monsoon is invariably linked with El Niño, resulting in below normal rains. The latest climate models indicate towards the beginning of Monsoon 2023 under the shadow of evolving El Niño. According to IMD, El Niño conditions are likely to develop during the monsoon season and may impact the second half of monsoon season.

Image Courtesy: NOAA

According to statistics, about 40% of the EL Nino years in the past (1951-2022) were years with normal or above normal monsoon rainfall.

Another oceanic phenomenon, Indian Ocean Dipole (IOD) which when in positive phase is linked with good Monsoon rains over the Indian landmass. At present, neutral IOD conditions are present over the Indian Ocean. The latest Climate models forecast indicates that the positive IOD conditions are likely to develop during the southwest monsoon season.

Image Courtesy: Bureau of Meteorology, Australia

Lastly, the snow-covered area over Northern Hemisphere (NH) as well as Eurasia was below normal during December 2022 to March 2023. Lower snow cover over NH as well as Eurasia during winter and spring is favourable for the subsequent southwest monsoon rainfall over India.

T​he IMD generates these long-term predictions using the Multi-Model Ensemble (MME) forecasting system, which is based on coupled global climate models (CGCMs) from different prediction centres, including IMD’s Monsoon Mission Climate Forecast System (MMCFS).

Meanwhile, the private forecasting company, Skymet Weather Services Pvt Ltd have predicted below normal rainfall for Monsoon 2023 to the tune of -94% of LPA, with error margin +/-5%.