IMD Forecasts Normal Monsoon Season with Some Regions Expected to Receive Below Average Rainfall

The India Meteorological Department (IMD) has forecasted that this year’s monsoon is likely to be “normal”. The IMD predicts that the southwest monsoon seasonal rainfall from June to September will range from 96% to 104% of the Long Period Average (LPA), indicating a normal monsoon season with a quantitative estimate of 99% LPA.

However, the IMD has indicated that certain areas in the country, especially states in northeast India, may experience below-normal rainfall during the monsoon season due to climate change. The South West Monsoon rainfall contributes 74.9% to the annual rainfall.

IMD Director General Dr. M Mohapatra mentioned that dry spells seen in recent years are part of the “decadal variability in India” of the monsoons. The new all-India rainfall normal is now 87 cm, based on data from 1971-2020, compared to the earlier normal of 88 cm from 1961-2010.

Dr. Mohapatra explained that the southwest monsoon is currently in a dry epoch starting in 1971-80, with a shift towards a neutral phase in the next decade (2021-30) and a wet phase following that. The new rainfall normal data is collected from 4,132 raingauge stations across 703 districts of India.

In terms of rainfall patterns, the IMD noted an increase in heavy rainfall days and a decrease in moderate and low rainfall days during the monsoon season. La Niña conditions are currently prevailing, with neutral IOD conditions over the Indian Ocean expected to continue until the start of the southwest monsoon season.

IMD is closely monitoring sea surface temperature conditions in the Pacific and Indian Oceans, as they strongly influence the Indian monsoon. Last year, IMD implemented a new strategy for issuing monthly and seasonal forecasts using a Multi-Model Ensemble (MME) forecasting system.

The forecast suggests normal to above normal seasonal rainfall in many areas of northern Peninsular India, foothills of the Himalayas, and parts of Northwest India. Below normal rainfall is expected in Northeast India, some parts of Northwest India, and southern South Peninsula.

Dr. Mohapatra stated that the impact of climate change on rainfall patterns in certain regions needs further investigation. IMD assesses climate change impact by analyzing maximum, minimum, and mean daily temperatures, oceanic and land temperatures, total monthly rainfall, and frequency of extreme weather events.

The new forecasting system was introduced to meet demands for spatial distribution forecasts of seasonal rainfall for better regional planning. The accuracy of the last monsoon forecast validates the effectiveness of the new model, with observed rainfall patterns aligning with the predictions.