Two global organisations have declared El Nino watch as there is a 50 per cent chance of the warm ocean water phenomenon associated with drought, heavy rains and floods across the world developing in the second half of the year.

Australia’s Bureau of Meteorology and Japan Meteorological Agency, in their latest outlook, have put El Nino  (the Spanish word for the little boy)  on watch in view of the likelihood of neutral conditions prevailing during the period.

‘Predictability barrier’ 

On the other hand, the Climate Prediction Center, a unit of the US National Oceanic and Atmospheric Administration, has forecast El Nino to develop during the same period and strengthen further towards the end of the year. 

The World Meteorological Organization (WMO), a unit of the UN, however, said the long-range ENSO (El Nino/La Nina Southern Oscillation) had to be forecast with caution. This is “due to the low performance of seasonal forecast models” at this time of year, commonly known as the Northern Hemisphere “spring predictability barrier”.

The India Meteorological Department (IMD) has said it will be able to say anything on El Nino development only in April in view of the “spring predictability barrier”. 

Visually: The El Nino effect

To persist through fall

The Climate Prediction Centre, in its “Probabilistic ENSO (El Nino/La Nina Southern Oscillation) Outlook” released on Monday, said the weather event would form in the summer of 2023 (July-September) and persist through fall (October-November). Later, it foresees “elevated chances” of El Nino developing further. 

Australia’s Bureau of Meteorology said there are some signs that El Niño “could form later in the year”. Hence, it has issued an El Niño watch. “This means there is around a 50 per cent chance of an El Niño in 2023,” the weather agency said.

La Nina over

Japan Meteorological Agency said it is likely (50 per cent) that El Niño conditions will develop, or ENSO-neutral conditions will persist in boreal summer (June-August). 

The Australian and Japanese organisations said the “triple dip” of La Nina had ended. La Nina developed in 2020-21, 2021-22 and 2022-23. The WMO said chances of El Niño developing gradually increase from 15 per cent in April-June to 35 per cent in May-July, reaching significantly higher chances of around 55 per cent during June-August.  

WMO said smaller chances of El Niño relative to the model predictions are primarily because ENSO forecasts made during the spring are less accurate. 

Impact on Indian monsoon

However, it is possible that strong warming near South America may portend a more rapid evolution towards El Niño.  

El Nino occurs when the surface water in the Pacific Ocean becomes warmer than average.

In previous years, India experienced deficient rainfall during the south-west monsoon. A paper on “El Nino and the Indian rainfall in June” published by Current Science said a massive 42 per cent rainfall deficiency in June 2014 could be attributed to El Nino.

However, with El Nino developing a little late this year, its impact will have to be watched out in the subcontinent, say experts.