Private weather forecaster Skymet has predicted a ‘below normal’ monsoon in India this year, the first time after it experienced “normal or above normal” rainfall during the past four years.

Quantitatively, it is seen to be 94 per cent of the normal, the distribution of rainfall will be the key to expect any adverse impact on agricultural crops. India Meteorological Department will issue its forecast on monsoon on Tuesday.

“We expect the upcoming monsoon to be ‘below normal’ to the tune of 94 per cent of the long-period average (LPA) of 868.6 mm during the four-month season (June-September), with an error margin of plus/minus 5 per cent,” Skymet said in a statement.

Monsoon rainfall between 90-95 per cent of LPA is considered as “below normal” and between 96-104 per cent of LPA is known as “normal”.

El Nino likelihood increasing

“Courtesy Triple-Dip-La Niña, the south-west monsoon was above normal/normal for the last four consecutive seasons. Now, La Niña has ended. Key oceanic and atmospheric variables are consistent with ENSO-neutral conditions. The likelihood of El Niño is increasing, and its probability to become a dominant category during the monsoon is growing large. El Niño return may presage a weaker monsoon,” said Jatin Singh, Managing Director of Skymet Weather.

Besides El Niño, Indian Ocean Dipole (IOD) has the potential to steer monsoon and negate the ill effects of El Niño when sufficiently strong. But, IOD is neutral now and is leaning to turn moderately positive at the start of the season, Singh said.

El Niño and IOD are likely to be ‘out of phase’ and may lead to extreme variability in the monthly rainfall distribution. The second half of the season is expected to witness more aberrations,” he said.

40% below normal probability

According to Skymet, the probability of a below-normal monsoon is 40 per cent, and for a drought (rainfall below 90 per cent of LPA) the chance is 20 per cent. Whereas there is a 25 per cent chance of normal precipitation and a 15 per cent probability for ‘above normal’.

It further predicted June to receive 99 per cent rainfall with of LPA of 165.3 mm, July to have a 95 per cent of LPA of 280.5 mm, August to receive a 92 per cent of LPA of 254.9 mm and September may get a 90 per cent of LPA of 167.9 mm.

“More than the quantum of total rainfall, it is the spatial and timely distribution which have a larger impact on agricultural production. If these turn out to be good, we can expect a handsome kharif crop,” said Siraj Hussain, former agriculture secretary. The country is estimated to have harvested a record 323.55 million tonnes (mt) of foodgrains in 2022-23 despite several parts of eastern India and Uttar Pradesh had either deficient or below normal rainfall last year.

The prediction of deficient rains in western and northern regions and below normal precipitation in central and eastern parts in 2023 is to be seen with how the monthly distribution will spread over each state in those regions, said S K Singh, a former agriculture scientist. Skymet has predicted normal rain in southern states, except Kerala and coastal Karnataka, may add both kharif and plantation crops.

Below normal a boon?

The private weather forecaster has said during July, Tamil Nadu, interior Karnataka, Odisha, Assam and Meghalaya may have normal rainfall whereas Gujarat, Rajasthan, Madhya Pradesh, and Maharashtra may experience below-normal showers. July is the wettest of the monsoon season, accounting for over 32 per cent of the total seasonal rainfall. Lower rainfall may affect the already sown pulses and soyabean crops in non-irrigated areas.

Singh said below normal rains during September in Gujarat, Maharashtra and Madhya Pradesh will be good for the cotton, tur and soyabean as these States had faced severe crop losses in the past few years due to above normal rains in September-October.