Normal monsoon likely, low probability of deficient rainfall: IMD

There is 14 per cent chance of a deficient rainfall and 30 per cent chance of a below normal precipitation. The chance for a normal rainfall is 42 per cent, 12 per cent for above normal rainfall and 2 per cent chance for excess precipitation.

The four-month monsoon season from June to September provides about 75 per cent of the annual rainfall to the country, where GDP is still largely driven by the agriculture sector. Several parts of India are witnessing agriculture distress and a good rainfall is likely to provide some relief.

D S Pai, a scientist with the IMD, said the La Nina condition is weakening and is highly likely to enter a neutral phase.

The Indian Ocean Dipole (IOD) is negative, but even that is reducing, Ramesh said. “Neutral La Nina is not detrimental for the monsoon,” Ramesh said.

La Nina is associated with cooling of the equatorial Pacific waters, while El Nino is associated with the warming of these waters. A positive IOD is associated with cooling of the equatorial waters of the Indian Ocean and a negative IOD is associated with the warming of these waters. These phenomena are one of the factors that impact the monsoon.

The date of onset of monsoon will be announced in the middle of May. Ramesh said it will also release the area wise distribution of rainfall by May-end or early-June.

Private weather forecasting agency Skymet recently said that there was only 20 per cent chance of above normal monsoon rains, 20 per cent chance of below normal rains and zero per cent chance of a drought. June would record excess rainfall, July is likely to be normal and August below normal, it had added. Rainfall activity will pick up again in September, Skymet had said.

The monsoon is considered normal if the average rainfall is between 96 to 104 per cent of long period average. Anything less than 90 per cent of LPA is termed a ‘deficient’ monsoon, and 90-96 per cent of the same is considered ‘below normal’.