ISTANBUL

The World Meteorological Organization (WMO) has warned that the currently active weak La Nina condition may transition into ENSO-neutral conditions and potentially develop into an El Nino later this year — a shift that could bring changes to global surface temperatures.

The recent weak La Nina weather event may soon transition to El Nino-Southern Oscillation (ENSO) neutral conditions, potentially developing into a warming El Nino later in the year, according to an announcement on the WMO website.

Occurring within the broader context of human-caused climate change, weather events like El Nino and La Nina compound global warming trends, strengthen extreme weather events, and severely alter seasonal precipitation and temperature patterns worldwide.

Forecasts indicate the probability of ENSO-neutral conditions occurring between March and May stands at 60%, rising to 70% for the April-June period. The likelihood of a La Nina persisting during this timeframe is low at approximately 30%, while El Nino is around 10%.

For the May-July period, neutral conditions carry a 60% probability, but the likelihood of El Nino forming climbs steadily to around 40%. Forecasts issued at this time of year are generally less reliable due to the ENSO spring barrier, a seasonal blind spot that historically affects prediction accuracy.

El Nino's Role in global temperatures, record-breaking heat

WMO Secretary-General Celeste Saulo stated in the announcement that the organization will closely monitor conditions in the coming months.

She noted that the 2023-2024 El Nino ranked among the five strongest on record and contributed to the record global temperatures seen in 2024.

"Seasonal forecasts for El Nino and La Nina help us avert millions of dollars in economic losses and are essential planning tools for climate-sensitive sectors like agriculture, health, energy and water management," Saulo said, adding that they also support humanitarian operations and disaster risk management.

Speaking to Anadolu, Murat Turkes, board member of the Center for Climate Change and Policies Application and Research at Istanbul’s Bogazici University, explained that both phenomena originate from shifts in sea surface temperatures in the Equatorial Central-Eastern Pacific, which in turn drive changes in pressure systems, ocean currents, and wind patterns.

Recalling the intense heat driven by the strong El Nino in 2023-2024, Turkes noted that 2024—fueled by El Nino's contribution—became both the hottest year in instrumental climate records and the first year the critical 1.5-degree global warming threshold was breached.

He pointed out that sea surface temperature anomalies currently show conditions running approximately 0.5 to 1–1.5°C below normal in the Equatorial Central-Eastern Pacific and parts of the Indian Ocean.

"When we look at the observations, there are relatively cooler-than-normal conditions right now in the Equatorial Central-Eastern Pacific and some parts of the Indian Ocean. This shows a weak La Nina phase is currently being experienced, rather than an El Nino signal," he said.

Neutral conditions dominant, El Nino possible

Turkes described the current state as near-neutral and said that while a transition to El Nino from July onward carries roughly a 40% probability, neutral conditions are projected to prevail through August.

He noted that El Nino-Southern Oscillation is a combined ocean-atmosphere event that occurs every 2 to 5, or in some periods 2 to 7, years — sometimes manifesting as a single or multi-year El Nino, sometimes as La Nina, and sometimes as neutral conditions — each with different regional and global climate impacts.

Should a strong El Nino develop after July — a scenario carrying roughly a 40% probability — Turkes said the additional impact on global surface temperatures could reach 0.1 to 0.2°C at the regional level, and up to 0.2 to 0.3°C globally if the event sustains through August, though he cautioned that any such projection remains highly uncertain.

*Writing by Zeynep Ozturhan in Ankara