After delivering a warm 2023, El Nino conditions are set to dissipate by June this year raising hopes of “bountiful monsoon” rains this season, meteorologists have predicted.
At least two global climate agencies announced last week that El Nino, the warming of the equatorial Pacific Ocean that impacts weather across the world, has started to weaken and there is a probability of La Nina conditions setting in by August.
Weather scientists in India, tracking the developments closely, have said that La Nina conditions setting in by June-August could mean monsoon rains would be better this year than the last year.
However, they also struck a word of caution citing the ‘spring predictability barrier’, considered a forecasting headache as weather models have a harder time making accurate forecasts.
Madhavan Rajeevan, former secretary in the Ministry of Earth Sciences, said there is a good probability of La Nina developing by June-July.
“Even if El Nino transitions into ENSO-neutral conditions, the monsoon this year should be better than the last year,” he said.
The southwest monsoon delivers about 70 per cent of India’s annual rainfall, critical for the agriculture sector that accounts for about 14 per cent of the GDP and employs more than half of its 1.4 billion population.
The United States’ National Oceanic and Atmospheric Administration (NOAA) said last week that there is a 79 per cent chance that El Nino will transition to ENSO-neutral by April-June and a 55 per cent chance of La Nina developing in June-August.
The European Union’s Copernicus Climate Change Service (C3S) confirmed that El Nino has started weakening. La Nina is the cyclic counterpart to El Nino.
“Currently, we cannot say anything with certainty. Some models indicate La Nina, while some predict ENSO-neutral conditions. However, all models suggest an end to El Nino,” D Sivananda Pai, a senior scientist at the India Meteorological Department, said.
NOAA, the American national forecaster, said there was a historical tendency for La Nina to follow strong El Nino events.
“The forecast team is in agreement with the latest model guidance, with some uncertainty around the timing of transitions to ENSO-neutral and, following that, La Nina,” the US agency said.
“But even if El Nino transitions into ENSO-neutral conditions, the monsoon this year should be better than last year,” the senior meteorologist said.
India received “below-average” cumulative rainfall of 820 mm compared to the long-period average of 868.6 mm in the 2023 monsoon season, which was attributed to a strengthening El Nino.
Assuming El Nino continues through the first half of 2024, the World Meteorological Organisation (WMO) earlier predicted that 2024 would be warmer than 2023, Pai said.
“If La Nina develops, 2024 would not be warmer than 2023,” he said.
Roxy Mathew Koll, a climate scientist at the Indian Institute of Tropical Meteorology, said latest forecasts indicate a quick transition to La Nina by June, which could result in an on-time and bountiful monsoon.
“At the same time, if high temperatures continue, it would mean intense cyclones and extreme rains too,” he said.
Koll said global temperature anomalies might continue despite the transition.
“We might think that a La Nina might result in a symmetrical effect, but it doesn’t have the same intensity as that of an El Nino. So the cooling-compensation effect that we might expect will be subdued. In fact, we have had warmer years during La Nina in the recent period, warmer than El Nino years in the past,” the scientist said. PTI