The Indian Meteorological Department (IMD) has released its long-range forecast for the 2024 Southwest monsoon season, spanning from June to September. The forecast indicates that the seasonal rainfall over the country is likely to be above normal, with a predicted value of 106% of the Long Period Average (LPA). This is a welcome prediction, as it surpasses the normal threshold of 104% of the LPA. The LPA for the season's rainfall from 1971-2020 stands at 87 cm.
The forecast is based on both dynamic and statistical models, which suggest a high probability (61%) of the southwest monsoon seasonal rainfall being above normal. However, there is a model error of ± 5% associated with these predictions.
Currently, moderate El Niño conditions are observed over the equatorial Pacific region. However, forecasts indicate a weakening of El Nino to neutral conditions in the early part of the monsoon season, with a subsequent transition to La Nina conditions in the latter half of the season. Similarly, neutral Indian Ocean Dipole (IOD) conditions prevail at present, but there is a likelihood of positive IOD conditions developing during the later part of the southwest monsoon season.
The IMD is closely monitoring sea surface temperature conditions in the equatorial Pacific and Indian Oceans, as these factors strongly influence the Indian monsoon. The transition from El Nino to La Nina, along with the development of positive IOD conditions, is expected to impact the monsoon pattern.
Additionally, the forecast considers the snow cover extent over the Northern Hemisphere. Below-normal snow cover observed from January to March 2024 is expected to favor rainfall during the southwest monsoon season.
Overall, the expected La Nina conditions, positive IOD, and below-normal snow cover over the Northern Hemisphere are favorable indicators for abundant rainfall during the 2024 southwest monsoon season.
IMD will issue updated forecasts for the monsoon season rainfall in the last week of May 2024, providing further insights into the evolving weather patterns and their potential impact on India's agricultural and water resources.
