India Meteorological Department (IMD) has reiterated the South-West monsoon may enter Kerala around June 4 (with a margin of plus or minus four days) and generate normal rainfall (between 96 to 104 per cent of the long-period average) for the country as a whole.

In the process, it will ride a beneficial positive phase of the Indian Ocean Dipole (IOD) and shrug off any adverse impact from a brewing El Niño in the Equatorial Pacific, though there is no direct cause-effect relationship between any of these. 

Draws parallel to 1997

Interacting with newspersons in a virtual press conference, DS Pai, Head, Environment Monitoring and Research Cell and Numerical Weather Prediction, IMD, drew a parallel to 1997 which saw one of the strongest El Niño events but which managed to deliver a normal monsoon season thanks to a concurrent positive IOD.

Lately, in 2019, a record-breaking positive IOD had not just delivered a record surplus monsoon (110 per cent) but stretched it into as late as October. 

To break impasse in two days

IMD expects the monsoon, currently stalled along the Nicobar Islands and adjoining South Andaman Sea and adjoining South-East Bay of Bengal, to make further advance in the next two days.

Thereafter, it sees cross-equatorial flows strengthening and likely setting up a conducive environment over the South-East Arabian Sea off Kerala to precipitate the onset around June 4. 

The IMD pointed to the development of a cyclonic circulation over the North Andaman Sea over the next two days (businessline had mentioned this development positing the circulation closer to the Myanmar coast), which would help bolster the flows across the Bay and help with the further advance of the monsoons across the Bay waters in the next two days.

High El Nino probability

Pai said IMD has assessed there is a raised 90 per cent probability the monsoon-unfriendly El Niño may develop and start impacting the monsoon.

The positive IOD phase may also evolve to neutralise the impact of the former. Rainfall during June is expected to be below normal (92 per cent for the country as a whole).

The June-September season may deliver normal to above normal rainfall for most areas of the South Peninsula, some areas of East-Central India, and many areas of North-East and extreme North India.

Normal to below normal rain is forecast for many areas of North-West India and adjoining Wes-Central India, northern parts of Peninsular India and along the foothills of the Himalayas.

Meanwhile, on Friday morning, super typhoon Mawar loomed menacingly in the West Pacific, more than 6,000 km away from Kolkata, continuing to divert the flows from the Bay.

It may maintain its status for two more days, but can’t prevent an active western disturbance from affecting North-West India.