El Niño phenomenon developed in the tropical regions of the Pacific Ocean for the first time in seven years

Weather of Arabia - (World Meteorological Organization (WMO)) - El Niño conditions developed in the tropical regions of the Pacific Ocean for the first time in seven years, paving the way for a possible rise in global temperatures and turbulent weather and climate patterns.

A new update from the World Meteorological Organization (WMO) predicts that there is a 90 percent chance that El Niño will continue through the second half of 2023. It is expected to be of at least moderate strength. The WMO update brings together forecasts and expert advice from around the world.

“The emergence of El Niño will greatly increase the likelihood of breaking temperature records and bringing more extreme heat to many parts of the world and the oceans,” said Professor Petteri Taalas, Secretary-General of the World Meteorological Organization (WMO).

“The WMO El Niño declaration is a signal to governments around the world to mobilize preparations in order to reduce impacts on our health, ecosystems and economies,” he said. "Early warnings and proactive action of extreme weather events associated with this major weather event is vital to saving lives and livelihoods," he added.

El Niño events occur on average every two to seven years, and episodes usually last nine to 12 months. It is a naturally occurring climate pattern associated with warming ocean surface temperatures in the central and eastern tropical regions of the Pacific Ocean. Rather, it is occurring in the context of human-induced climate change.

In anticipation of El Niño, a WMO report in May predicted that there was a 98 per cent chance that at least one of the next five years, and the five-year period as a whole, would be the warmest on record, breaking the record set in 2016 when El Niño was exceptionally strong.

The WMO report issued in May, led by the UK Met Office in collaboration with partners around the world, said there was a 66 per cent chance that the annual mean global near-surface temperature between 2023 and 2027 are provisionally 1.5°C above pre-industrial levels for at least one year.

Professor Chris Hewitt, Director of WMO Climate Services, said: “This does not mean that in the next five years we will exceed the 1.5°C level specified in the Paris Agreement because this agreement indicates long-term warming over many years. However, the This is yet another wake-up call, or early warning, that we are not yet on the right track to limit warming within the targets set in Paris in 2015 that aim to significantly reduce the effects of climate change."

According to WMO's State of the Global Climate reports, 2016 is the warmest year on record due to the "double whammy" of a very strong El Niño and anthropogenic warming of greenhouse gases. The impact on global temperatures is usually seen in the year following its development, and is therefore likely to be more pronounced in 2024.

The global average temperature in 2022 was about 1.15°C higher than the 1900-1850 average due to the triple cooling La Niña phenomenon.

Typical effects of El Niño

El Niño is usually associated with increased precipitation in parts of southern regions of South America, the southern United States, the Horn of Africa, and central Asia.

Correspondingly, El Niño would also cause severe droughts over Australia, Indonesia, parts of southern Asia, Central America, and northern regions of South America.

During the boreal summer, warm El Niño waters can feed hurricanes in the central/eastern Pacific Ocean, while they can hinder hurricane formation in the Atlantic Basin.

El Niño generally has the opposite effect of the more recent La Niña, which ended earlier in 2023.

Current situation and prospects

Since February 2023, the mean monthly SST anomalies in the central eastern tropical Pacific Ocean have increased significantly, going from about half a degree Celsius below average (-0.44 in February 2023) to about half a degree Celsius above average ( +0.47 in May 2023). In the week centered on June 14, 2023, the warm sea surface temperature anomaly continued to increase, reaching a value of +0.9°C.

Collective evidence from ocean and atmospheric observations strongly indicates the presence of El Niño conditions in the Pacific Ocean. However, some mystery remains due to the weak ocean-atmosphere coupling, which is crucial to the exacerbation and persistence of El Niño. It is expected to take about another month or so to see coupling fully established in the tropical Pacific.

Seasonal update of global climate

El Niño and La Niña phenomena are the main drivers - though not the only ones - of Earth's climate system. In addition to the long-standing ENSO, WMO now issues regular Seasonal Global Climate Updates (GSCU), which include the impacts of all other major climate drivers such as the North Atlantic Oscillation, Arctic Oscillation, and Polar Bilateral Indian Ocean.

The latest update for July, August and September 2023 states that “because warmer-than-average sea surface temperatures are generally predicted over oceanic regions, they contribute to the widespread prediction of higher-than-normal temperatures over land regions.” Without exception, a positive temperature anomaly is expected over all land areas in the northern and southern hemisphere.

Precipitation forecasts for the next three months are similar to some of the standard precipitation effects of El Niño.

The WMO El Niño, Southern Frequency (ENSO) and WMO Global Monsoon Climate Updates are based on forecasts from the WMO Global Long-Range Forecasting Centers and are made available to support governments, the United Nations, decision-makers and stakeholders in climate-sensitive sectors in mobilizing Preparations and protection of lives and livelihoods.

NMHSs will closely monitor the evolution of El Niño conditions and associated effects on national and local temperature and precipitation. WMO will provide updated forecasts over the coming months as needed.

Probabilistic forecasts of surface air temperature and precipitation for the July-September 2023 season. The baseline period is 1993-2009.