Why is it in the news?

• The India Meteorological Department (IMD) forecasted above-normal temperatures and an increased number of heatwave days for March to May, while the World Meteorological Organisation (WMO) reported that the 2023-24 El Niño, one of the five strongest on record, has peaked and is gradually weakening but will still influence global climate in the coming months.

About El Niño

• El Niño refers to abnormal warming of sea surface waters in the equatorial Pacific Ocean.
• The current El Niño event, which started in June the previous year, has peaked and is gradually weakening.
• El Niño typically lasts for 9 to 12 months and affects global weather patterns, leading to increased temperatures, dryness, and disruptions in rainfall patterns.

Impact on India and Southwest Monsoon:

• El Niño conditions have led to above-normal temperatures and an increased number of heatwave days predicted for March to May.
• IMD forecasts harsher heatwaves, with above-normal temperatures expected in several regions, including Ladakh, Himachal Pradesh, Rajasthan, Uttar Pradesh, etc.
• Heatwaves are expected to be longer and harsher, particularly in Maharashtra, Telangana, and North Karnataka.
• The Indian summer monsoon, critical for the country’s agriculture and water reservoirs, typically occurs from June to September.
• El Niño events historically correlate with below-average rainfall during the monsoon season. However, this year, ENSO neutral conditions are predicted to emerge during April-June.
• The transition to ENSO neutral conditions may occur by May, potentially minimizing the direct impact of the ongoing El Niño episode on the southwest monsoon.
• The establishment of favourable oceanic conditions ahead of the monsoon onset could lead to normal monsoon rainfall, provided other atmospheric parameters remain favourable.

Conclusion

• The IMD is expected to release the Long Range Forecast (LRF) for the upcoming southwest monsoon by mid-April.
• The prediction of ENSO neutral conditions suggests that the southwest monsoon may not be directly impacted by the ongoing El Niño episode.
• There are chances of normal monsoon rainfall this year, contingent upon various factors such as ocean-atmosphere parameters, wind conditions, and the formation of low-pressure systems.