El Nino fears recede as global agencies scale back threat

Rajalakshmi S Updated - December 07, 2021 at 02:03 AM.

BL10-EL_NINO_1

In what should come as music to farmers’ ears, some international weather models have reduced the likelihood of an El Nino phenomenon rolling out in the tropical Pacific this year.

The anomalous warming of this part of the Pacific has been associated with a drier monsoon in India, though there is no direct one-to-one correlation between the two.

Not ruled out
Giving the latest update, the Australian Bureau of Meteorology said, however, that an El Nino cannot be entirely ruled out during the course of the year.

Five of eight models surveyed still indicate that the El Nino thresholds for sea-surface temperatures may be exceeded during the second half of this year.

Meanwhile, an early forecast method at the Potsdam Institute for Climate Impact Research said that the monsoon would reach Central India between June 14 and 22.

The timeline suggested by the German institute more or less corresponds with the normal dates of the monsoon onset in the region, as set by the India Met Department.

Data analysis The Institute based its prediction on an analysis of observational data that helped it to declare a monsoon onset date more than a month in advance for Central India.

Elena Surovyatkina led this study, which proved to be accurate last year. The monsoon onset date is of crucial importance for Indian farmers feeding a population of more than one billion, she said.

Climate change will likely affect monsoon stability and hence make accurate forecasting even more important, she added.

Although the rainy season happens annually, between June and September, the time of the monsoon season’s onset and withdrawal varies within a month from year to year.

Significant challenge “The important feature of the monsoon is that it starts and ends suddenly. Hence, forecasting it remains a significant scientific challenge,” says Surovyatkina.

“However, this helped me to realise that the sudden onset of the monsoon means a threshold behaviour, and inspired me to apply the theory of critical transition for a prediction of the monsoon.”

The long-term forecast means 40 days in advance for the onset date, and 70 days in advance for the withdrawal date. The prognosis is provided yearly, before and during the monsoon season.

Local events such as a pair cyclones from both sides of the Indian subcontinent can stop the monsoon for a week. Such random events are unpredictable. In such cases, the forecast will be updated.

The Potsdam Institute will issue a forecast for the monsoon withdrawal on July 27.

Published on May 9, 2017 07:55