Representative image of a rainy day.
Credit: iStock Photo
New Delhi: India is likely to experience a normal monsoon this year, private weather forecasting agency Skymet said on Tuesday and predicted more rainfall in the second half of the season.
Scientists at the India Meteorological Department (IMD) have also detected early signs of a favourable monsoon season this year with fading El Nino conditions and reduced snow cover over Eurasia. The Met office will issue a monsoon forecast later this month.
However, normal cumulative rainfall does not mean uniform temporal and spatial distribution of rain across the country, with climate change further increasing the variability of the rain-bearing system.
Climate scientists say the number of rainy days is declining while heavy rain events - more rain over a short period - are increasing, leading to frequent droughts and floods.
Skymet said the upcoming monsoon is expected to be "normal", accounting for 102 per cent (with an error margin of 5 per cent) of the long-period average (LPA) of 868.6 mm for the four months from June to September.
Rainfall between 96 per cent and 104 per cent of the LPA is considered normal.
Skymet expects sufficiently good rains in the south, west, and northwest regions. The core monsoon rain-fed zones of Maharashtra and Madhya Pradesh will receive adequate rainfall.
However, the eastern states of Bihar, Jharkhand, Odisha, and West Bengal are at risk of deficit rainfall during the peak monsoon months of July and August. Northeast India is likely to observe less than normal rains during the first half of the season.
According to Jatin Singh, the managing director at Skymet, "El Nino is swiftly flipping over to La Nina. And, monsoon circulation tends to be stronger during La Nina years." Also, the transition from Super El Nino to strong La Nina has historically tended to produce a decent monsoon. However, the monsoon season may start with a risk of impairment, attributable to the remnant effects of El Nino. The second half of the season will have an overwhelming edge over the primal phase," he said.
India received "below-average" cumulative rainfall of 820 mm compared to the long-period average of 868.6 mm in 2023, an El Nino year. Before 2023, India recorded "normal" and "above-normal" rainfall in the monsoon season for four years in a row.
El Nino conditions - periodic warming of surface waters in the central Pacific Ocean - are associated with weaker monsoon winds and drier conditions in India.
IMD officials earlier this month said La Nina conditions, associated with a favourable monsoon in India, are likely to set in during the second part of the season.
Three large-scale climatic phenomena are considered for forecasting monsoon season rainfall.
The first is El Nino, the second is the Indian Ocean Dipole (IOD), which occurs due to differential warming of the western and eastern sides of the equatorial Indian Ocean, and the third is the snow cover over the northern Himalayas and the Eurasian landmass, which also has an impact on the Indian monsoon through the differential heating of the landmass.
A preliminary forecast of a positive IOD this season will work in tandem with La Nina for better monsoon prospects, Skymet said.
Nonetheless, the start of the season is expected to be aberrated due to the quick transition from El Nino to La Nina. Also, the rainfall distribution is likely to be diverse and inequitable for the season as a whole, it said.
The southwest monsoon delivers about 70 per cent of India's annual rainfall, which is critical for the agriculture sector. Agriculture accounts for about 14 per cent of the GDP and employs more than half of its 1.4 billion population.