Southwest Monsoon likely to be below normal this year: Skymet

Monsoon rains may be "below normal" this year, Skymet, a private weather forecasting agency, said on Wednesday attributing it to the El Nino phenomenon.

The monsoon is likely to be 93 per cent of the long period average (LPA), it said. Anything between 90-95 per cent of LPA falls under the "below normal" category. LPA is the average of rainfall between 1951 and 2000, which is 89 cm.

If the forecast comes true, then this will be the second consecutive year of a below normal rainfall.

East India, along with a major portion of central India, is likely to be at a higher risk of being rain deficient, especially during the first half of the season.

Odisha, Chhattisgarh and Coastal Andhra Pradesh are most likely to see normal rains throughout the season, the forecast said.

Agriculture, the major contributor to the Indian GDP, still heavily relies on seasonal rains.

Skymet CEO Jatin Singh said June may see rainfall of 77 per cent of LPA, while July is expected to witness rainfall of 91 per cent of LPA.

According to the forecast, June and July are likely to witness "below normal" rainfall. August and September are likely to witness rainfall of 102 per cent and 99 per cent of LPA, Singh said.

"There is a 55 per cent chance of a below normal rainfall, zero chances of an excess and above normal rainfall and 30 per cent chance of a normal rainfall," the forecast said.

Skymet blamed the El-Nino behind a possible below normal rainfall. The El-Nino phenomenon is linked to the warming of Pacific waters.

El-Nino has an impact on the monsoon, Air Vice Marshal (retired) G P Sharma, Skymet President (Meteorology and Climate Change), said.

"The Pacific Ocean has become strongly warmer than average. The model projections call for 80 per cent chance of El Nino during March-May, dropping to 60 per cent for June to August.

"This means, it is going to be a devolving El Nino year, though retaining threshold values all through the season. Thus, Monsoon 2019 is likely to be below normal," Sharma said.

He added that the three-monthly Nino index shows that by MJJ (May-June-July), there is a 66 per cent chance of El Nino, 32 per cent chance of neutral and two per cent of La Nina.

La Nina is linked to cooling of Pacific waters and is generally believed to be good for the monsoon.

The saviour factor, the Skymet said, could be IOD (Indian Ocean Dipole) which is likely to be in the neutral or positive phase during the monsoon.

Thus, it may be able to absorb some of the El Nino blues and possibly would support rainfall during the second half of monsoon, Sharma said.

The IOD is linked to cooling of Indian Ocean waters. A positive IOD is generally good for the monsoon.