El Nino seen choking moisture feed into Bay, Arabian Sea to deny rains

Updated forecasts issued by Asia Pacific Climate Centre in Busan, South Korea, shows just how a building El Nino will proceed to pull the plug on the Indian monsoon.

India may be known as the monsoon country but the appendage builds mainly on the size of the landmass. Fact is that it is only one of the many beneficiaries of the larger Asian monsoon system.

Seasonal winds fan the monsoon into India and the rest of South Asia which also includes Afghanistan, Pakistan, Bangladesh, Sri Lanka, Myanmar and the rest of South-East Asia.

These winds mop up moisture from the seas which gets rained down across the geography. There is no way the system can ensure an equitable distribution of moisture/rain to each country.

This is because winds don’t care about geographical boundaries and merely blow from an area of high pressure to one of lower pressure.

Warming of the surface (land or sea) causes surrounding air to heat up and expand, creating lower pressure.

Thus, the warming/cooling of the massive Pacific with a size that can hold continents together is crucial in that its impact can drastically alter global weather or climate patterns.

During an El Nino, equatorial and east Pacific warms up, causing bulk of available moisture to concentrate there.

When coinciding with the Indian monsoon, it will deny the Bay of Bengal and the Arabian Sea their due share of ‘this fuel that fires the monsoon engine.’

The Korean agency forecast projects both seas being ‘drained to a slow death’ during the monsoon even as it will rain down heavily in the east Pacific and Americas where incremental moisture will have headed.

It is not just India that suffers in the bargain. Entire Maritime Continent (the Indonesian archipelago, etc) and most of Australia are also projected to pile up moderate to heavy rain deficits until September.

Latest forecasts from the agency say that the first phase of the monsoon (May-June-July) will leave central India and adjoining west India and the west coast in deficit.

Likely exceptions are Tamil Nadu, parts of Rajasthan, Punjab, Jammu and Kashmir, Himachal Pradesh, and Uttarakhand. Excess rain is likely over north-west Rajasthan and adjoining south-west Punjab.

The second phase (August-September-October) will see peninsular India, Gujarat and south-west Rajasthan drying up. Excess rain will be confined to parts of Madhya Maharashtra, Marathwada and Seemandhra.