Agri Business

This despite a brewing, and likely intensifying, monsoon-unfriendly negative Indian Ocean Dipole

The Application Laboratory of the Japanese national weather forecaster Jamstec has predicted that India is likely to witness ‘wetter than normal’ (above-normal rainfall) during July, August and September, though with regional variations in actual precipitation, a typical feature associated with the ongoing South-West monsoon.

Rains will be heavier over parts of the West Coast (Coastal Karnataka to Mumbai) and adjoining interior Maharashtra (Madhya Maharashtra and Marathawada) and North Interior Karnataka; normal to slightly above-normal over Central and East India (South Gujarat, Madhya Pradesh, East Chhattisgarh, Jharkhand, East Uttar Pradesh, Bihar and adjoining foothills, West Bengal and adjoining North-Eastern States.)

Regional rainfall variations

Rainfall will be normal to below-normal over most of Odisha and the northern parts of the North-Eastern States, as per the Japanese forecast. Its above-normal outlook for the country as a whole aligns with India Meteorological Department’s (IMD) upgrading the monsoon from 99 per cent to 103 per cent above the long-period average during this season. This is despite its sluggish progress so far, with many areas in East and Central India yet to receive the first showers.

In its forecast, the Japanese agency grouped India along with western and northern parts of Canada, Central America, Venezuela, Guyana, eastern Australia, Eritrea, Ethiopia, Nepal, some parts of China, Eurasia and Indochina, and Indonesia to go likely under a wetter-than-normal rainfall regime during the period under reference.

Negative IOD evolving

However, drier-than-normal (below-normal rainfall) conditions are predicted for most parts of the North American continent, northern parts of the South American continent, La Plata, Chile, West and Central Africa, northern Mediterranean, some parts of China, Eurasia, Indochina and the Philippines.

The Japanese outlook comes in the context of its having declared that a monsoon-unfriendly negative Indian Ocean Dipole (IOD) has set in. It It will mature through the monsoon and beyond, before decaying in winter. There is even an enhanced (80 per cent) chance of it turning into an extreme negative IOD when the dipole index drops to below -1.5 degrees Celsius (currently it is around -.5 degree Celsius).

La Nina prevails, to linger

The overarching extended La Nina in Equatorial Pacific, traditionally considered helpful for a concurrent monsoon in India, is predicted to continue into September-December, beyond the South-West monsoon. Given this, it is likely that the Indian Ocean and the Pacific will likely vie with each other to establish dominance; but if India has to have a good monsoon, then La Nina has got to prevail.

Published on June 15, 2022