Southwest monsoon rains to be above-normal: IMD

Weather forecaster India Meteorological Department (IMD) on Monday said the 2024 southwest monsoon rainfall over the country as a whole is most likely to be above-normal.

India is expected to witness above-normal rainfall in the four-month monsoon season (June to September) with cumulative rainfall estimated at 106% of the long-period average (87 cm), says IMD.

IMD has been issuing the operational long-range forecast for the southwest monsoon seasonal (June-September) rainfall averaged over the country as a whole in two stages. The first stage forecast is issued in April and the second stage updated forecast is issued by the end of May. IMD will issue the updated forecasts for monsoon season rainfall in the last week of May 2024.

Currently, moderate El Niño conditions are prevailing over the equatorial Pacific region. The latest Monsoon Mission Climate Forecast System (MMCFS) as well as other climate model forecasts indicate that the El Niño condition is likely to weaken further to neutral El Nino Southern Oscillation (ENSO) conditions during early part of the monsoon season and La Niña conditions are likely to develop during second half of monsoon season, says IMD.

At present, neutral Indian Ocean Dipole (IOD) conditions are prevailing over the Indian Ocean and the latest Climate model forecasts indicate that the positive IOD conditions are likely to develop during the later part of the southwest monsoon season.

Winter and spring snow cover extent over the Northern Hemisphere as well as Eurasia has a generally inverse relationship with the subsequent Indian summer monsoon rainfall. The northern hemisphere snow cover areas during January to March 2024 were observed to be below-normal. The expected La Nina, positive IOD and below-normal snow cover over the northern hemisphere would be favourable for rainfall during the southwest monsoon season, 2024.

IMD had earlier warned of a heatwave with above-normal temperatures in most parts of the south peninsula, central India, east India and plains of northwest India during the hot weather season (April-June). above-normal maximum temperatures are likely over most parts of the country, except some parts of east and northeast India and pockets of northwest India where normal to below-normal maximum temperatures are likely, the national weather forecaster said.

For the month of April, above-normal maximum temperatures are likely over most parts of the country, said IMD. However, isolated pockets of east, northeast and northwest India are likely to experience normal to below-normal maximum temperatures, it said.

Normal to above-normal rainfall is likely over most parts of the northwest India and many parts of central India, north peninsular India, some parts of east and north east India, IMD said. Below normal rainfall is likely along east and west coasts, some parts of east and northeast India and west central India, it added.

During heatwaves, elevated temperatures pose significant risks, especially for vulnerable populations like the elderly, children, and those with pre-existing health conditions, who are more susceptible to heat-related illnesses such as heat exhaustion and heatstroke.