WMO Specifies a 70% Probability for La Niña Between August and November, While El Niño Remains Negligible

According to the World Meteorological Organization (WMO), the probability of the La Niña phenomenon occurring, which brings cooler temperatures, is 70% between August and November. This probability is 50% for the period from June to August 2024.

However, the WMO, based in Geneva, clarifies that the probability of El Niño returning during this period is almost negligible.

The effects of La Niña vary depending on the intensity and duration of the episode, the time of year, and its interaction with other climatic phenomena. La Niña is generally characterized by the cooling of the eastern Pacific Ocean over a period of one to three years.

2023: The Hottest Year Ever Recorded

At the same time, La Niña could lead to wetter conditions in parts of Australia, Southeast Asia, and southeastern Africa, but drier conditions elsewhere.

Overall, even though La Niña is known for its cooling effect, its impact might go unnoticed due to the ongoing global warming.

The WMO indicates that exceptionally high sea surface temperatures will continue to play a significant role in the coming months.

Since June 2023, temperature records have been broken every month, making 2023 the hottest year ever recorded. Ko Barrett, WMO Deputy Secretary-General, emphasized that the end of El Niño does not mean a pause in long-term climate change, as greenhouse gases will continue to trap heat.

The Persistent Influence of Global Warming

This WMO clarification comes as the last nine years have been the hottest on record, despite the cooling influence of La Niña from 2020 to early 2023.

There remains considerable uncertainty about the intensity and duration of a La Niña episode due to the historically low performance of seasonal forecast models for this time of year, known as the “spring predictability barrier” in the Northern Hemisphere, explained the WMO.

Intense El Niño episodes are generally followed by typical La Niña conditions, which aligns with recent model forecasts. However, weather conditions will continue to be more extreme due to the excess heat and moisture in the atmosphere.

Therefore, the “Early Warnings for All” initiative remains the UN’s top priority, added Ms. Barrett, who leads the WMO delegation at the United Nations Climate Change Conference in Bonn.