India is likely to experience below-normal monsoon rainfall this year, with a 20 per cent chance of drought due to the end of La Nina conditions and the potential for El Nino to take hold, private forecasting agency Skymet Weather said on Monday.
After four consecutive years of normal and above-normal rains during the monsoon season, this forecast comes as a concern for the agricultural sector, which heavily relies on monsoon rains for crop production.
Skymet expects the monsoon rainfall to be around 94 per cent of the long-period average (LPA) of 868.6 mm for the four-month period from June to September.
The private forecaster also predicted that the northern and central parts of the country may see a rain deficit, with Gujarat, Madhya Pradesh and Maharashtra expected to witness inadequate rains during the core monsoon months of July and August.
Punjab, Haryana, Rajasthan and Uttar Pradesh, the agricultural bowl of north India, are likely to observe less-than-normal rains during the second half of the season.
In a statement, Skymet said: "20 per cent chance of drought (seasonal rainfall that is less than 90 per cent of LPA)."
It said there is no chance of excess rain (seasonal rainfall more than 110 per cent of the LPA), a 15-per cent chance of above normal rain (between 105 per cent and 110 per cent), 25-per cent chance of normal rain (between 96 per cent and 104 per cent) and 40 per cent chance of below normal precipitation.
The India meteorological department (IMD) is yet to release its forecast for the monsoon season, but it has predicted above-normal maximum temperatures and heatwaves in most parts of the country from April to June.
Jatin Singh, managing director of Skymet, said the return of El Nino could presage a weaker monsoon this year.
El Nino, which is the warming of the waters in the Pacific Ocean near South America, is associated with weakening of monsoon winds and less rainfall in India.
"La Nina has ended. Key oceanic and atmospheric variables are consistent with ENSO-neutral conditions. Likelihood of El Nino is increasing and its probability to become a dominant category during the monsoon is growing large," Singh said.
La Nina conditions -- characterised by the cooling of the waters in the Pacific Ocean near South America -- favours the Indian monsoon.
However, Skymet also noted that the Indian Ocean Dipole (IOD) could steer monsoon and negate the ill-effects of El Nino when sufficiently strong.
Currently, the IOD is neutral and is expected to turn moderately positive at the start of monsoon.
Skymet Weather said El Nino and the IOD are likely to be "out of phase" and may lead to extreme variability in the monthly rainfall distribution, with the second half of the season expected to be more aberrated.
The IOD is defined by the difference in the sea surface temperatures between the western parts of the Indian Ocean near Africa and the eastern parts of the ocean near Indonesia. A positive IOD is considered good for the Indian monsoon.