El Niño to dry up early monsoon, July to Sept may be wet as usual

The country is likely to see a below-par monsoon this year, predicted to be 93 per cent of the long-period average of 887mm from June till September, private weather forecaster Skymet said in its annual monsoon forecast on Wednesday. The probability of a below-par monsoon stands at 55 per cent, give or take 4 per cent. However, after a sluggish start in June and July, August and September are expected to be as wet as usual.

Eastern and central regions are likely to see poorer rainfall in the first half, while Odisha, Chhattisgarh and Coastal Andhra Pradesh are most likely to see normal rains throughout the season.

Skymet based its forecast on an 80 per cent chance of El Niño conditions between March and May.

El Niño is warm sea surface temperature over equatorial Pacific ocean which causes poor rainfall in South Asia. According to the IMD's recent observations, El Niño is currently in a weak phase with a strong influence on intense summer heat.

"The Pacific Ocean is warmer than average," said Jatin Singh, MD of Skymet, "The model projections call for 80 per cent chance of El Niño during March-May, dropping to 60 per cent for June to August. This means, it is going to be a devolving El Niño year, though retaining threshold values all through the season. Thus, Monsoon 2019 is likely to be below normal."

However, the Indian Ocean Dipole (IOD) could save the country from a poor monsoon as it may be able to absorb some of the El Niño blues and support rainfall in the second half of monsoon. IOD is essentially one of the key strong factor affecting monsoon in the country. IMD defines IOD as the anomalies in cooling and warming in the western and eastern Indian Ocean. Warming in the western Indian Ocean near Eastern Africa results in a good monsoon while warming of the eastern Indian Ocean can lead to the opposite.