NEW DELHI: Climate experts from nine South Asian countries and other global agencies concurred on Tuesday that most parts of the South Asian region will experience above-normal rainfall during the 2024 southwest monsoon season (June – September). They concluded that factors affecting the southwest monsoon, such as positive Indian Ocean Dipole, below-average snowfall in the Northern Hemisphere, and cooling of the eastern Pacific Ocean, are favouring the rainfall season.
The 28th session of the South Asian Climate Outlook Forum (SASCOF-28) was held at the Pune-based climate service research centre of the Indian Meteorological Department on April 29. Participants included representatives from nine South Asian countries, the World Meteorological Organization, the Met Office UK, Japan, Korea, and others.
In its statement, SASCOF states that except for some areas over northern, eastern, and north-eastern parts of the region, the rest will receive above-normal rainfall during the 2024 southwest monsoon season.
“There is a strong consensus among the experts that La Niña conditions are likely to develop over the equatorial Pacific during the second half of the southwest monsoon season,” mentioned in a statement by SASCOF. It is worth mentioning that La Niña conditions are generally associated with normal to above-normal southwest monsoon rainfall over most parts of South Asia, while El Niño condition is synonymous with poor monsoon.
El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern Pacific Ocean, while La Niña is the cyclic counterpart to El Niño, known for the cool phases of a recurring climate pattern across the tropical Pacific.
Climate experts analysed different factors that impact the southwest monsoon, such as El Niño-Southern Oscillation (ENSO) conditions over the Pacific Ocean, Indian Ocean Dipole (IOD) conditions over the Indian Ocean, and snow cover over the Northern Hemisphere (NH).
A positive (negative) IOD is associated with stronger (weaker) than normal southwest monsoon over the region. Experts agreed that the current IOD is in a neutral condition, and different models indicate that favourable positive IOD conditions would develop later in the southwest monsoon season. The NH winter and spring snow cover extent generally has an inverse relationship with the subsequent southwest monsoon rainfall over South Asia. The NH snow cover areas during January to March 2024 were below normal.
The snow cover area during February and March respectively was the 8th and 7th lowest ever recorded during the past 58 years, which further boosts the southwest monsoon. During the season, above-normal minimum temperatures are most likely over most parts of South Asia, except for a few areas over the south-eastern part of the region, where normal temperatures are most likely.