An early European forecast is for a potential strong El Nino for the planet later this year. Photo / 123RF
The planet may experience a strong or even a super El Nino later this year, one that could rival the strongest ones in history, according to new climate data released by the European Centre for Medium-Range Weather Forecasts (ECMWF).
A typical El Nino affects regional-to-global weather patterns, as a warming patch of water in the equatorial Pacific Ocean influences what regions could experience droughts, floods and extreme heat.
During these relatively rare super El Nino events, happening once every 10 to 15 years on average, the effects may be stronger, more persistent and more widespread.
That’s because sea temperatures in that key region of the Pacific Ocean warm more than 2C above average, leading to a profound atmospheric response.
Those impacts can include the frequency and location of heatwaves, the locations of flooding downpours and drought could focus, where hurricanes may hit, and declining sea ice concentrations.
For example, the western United States could face a hotter than average summer, some tropical countries could face worse drought and extreme heat, while more tropical cyclones could develop in the Pacific, with fewer in the Atlantic.
There’s also a growing chance that this year’s El Nino, especially if it’s a strong one, would push global temperatures to record levels, particularly in 2027.
It’s a possibility that has the attention of climate scientists, though there are a range of views on how strong it may become.
“Whew,” wrote climate scientist Daniel Swain last week in a post on X. “All signs are increasingly pointing to a significant, if not strong to very strong, El Nino event.”
This year’s El Nino is looking increasingly likely to have wide-reaching impacts across the planet.
It’s still in its developmental stages and it’s too early to confidently say just how strong it may become, but its tendencies have been similar to major events in the past - boosted by record-breaking westerly wind bursts in the Pacific, which blow warm water eastward.
No two El Nino events are exactly alike, but here are some of the possibilities.
Harsh winds in the middle and upper atmosphere during formidable El Nino events can create conditions that are less conducive to hurricane formation.
“Overall, this would be about as unfavourable an Atlantic look as you could get for the peak of hurricane season,” wrote meteorologist Andy Hazelton, who has been tracking this potential El Nino’s impact on the upcoming Atlantic hurricane season, which starts on June 1.
Even if there are fewer storms, El Nino doesn’t tell you where hurricanes may go. It only takes one landfall - as demonstrated by Hurricane Andrew in Florida in 1992 - for it to be a memorable season.
The strongest El Nino events almost always cause a record warm year. That’s because heat comes out of the ocean during El Nino, overspreads the tropics in the Pacific, then gets redistributed across the planet.
“The El Nino cometh,” wrote climate scientist Zeke Hausfather.
“This would push up our estimate for 2026 global temperatures (though it’s still unlikely to surpass 2024 as the warmest year) and make 2027 very likely to be the warmest year on record,” he said, citing that air temperature increases lag behind El Nino’s development.
Strong El Nino periods often appear as an upward stairstep in long-term plots of global temperatures.
“Due to the increasing concentration of greenhouse gases, the climate system cannot effectively exhaust the heat released in a major El Nino event before the next El Nino comes along and pushes the baseline upward again,” US Defence Department meteorologist Eric Webb said.
Therefore, a super El Nino in 2026-27 would disperse more heat than other very strong events in 1982-83, 1997-98 and 2015-16.
El Nino can have wide-reaching influences on global weather patterns - where the same sources of building heat can have varying consequences across the planet.
A marine heat wave building near the West Coast - partly linked to El Nino’s development - could influence a hotter-than-average summer across the western US, further increasing the wildfire risk amid ongoing droughts.
Meanwhile, Hawaii could encounter more tropical storms and hurricanes this year, fuelled by a patch of warm water extending across the subtropical and tropical eastern Pacific - because of an El Nino-linked phenomenon called the Pacific Meridional Mode.
Starting in the middle of the year, there will be potential for more typhoons in the western Pacific, including across the Philippines, China and Japan.
India’s monsoon, which runs from June to September, could also be affected, with less rain than normal across the subcontinent.
Drought could also build across Australia and Indonesia, parts of eastern Africa and the Caribbean islands, while downpours soak Peru, Ecuador and Hawaii.
During the 2015-16 super El Nino, droughts hit Ethiopia, Somalia, Haiti, Central America, Papua New Guinea and Vietnam particularly hard.
Tropical countries across South America, Africa and the Middle East as well as India and Australia will likely swelter under extreme heat and/or humidity, coinciding with a rise in tropical sea temperatures and/or drought in some areas.
Late in the year, a stronger southern branch of the jet stream could influence heavy downpours and the potential for flooding, including across some southern US states dealing with drought, such as Florida. That stronger southern jet stream can also increase the chance for flooding wintertime downpours in California.
El Nino can also have a moderating effect on winter temperatures, as the northern branch of the jet stream is nudged farther north and frigid air less frequently ventures southward into the US.
Although a forecast update will come out later this week, the National Oceanic and Atmospheric Administration is currently favouring El Nino development.
Michelle L’Heureux, the lead forecaster for Noaa’s updates on the El Nino-Southern Oscillation, said her team uses a multi-model approach because it provides more reliable predictions.
“If we look across a lot of different models, the realm of possibilities ranges from a weak La Nina to a strong El Nino,” she said.
Noaa’s key seasonal climate forecasting system, called the North American Multi-Model Ensemble, trended towards a stronger El Nino forming this year - in line with ECMWF - in an update released at the weekend.
While L’Heureux considered the new outlook from ECMWF to be an interesting data point, she added that these predictions are also being made in spring, under the influence of the spring prediction barrier, a time of less accurate El Nino predictions.
She also said there is ample historical precedent for models predicting big El Nino events in the spring that don’t come to fruition because westerly wind bursts pause or cease, with 2014 being an example.
“I realise there is interest in these El Nino forecasts because we often see El Nino form in advance of their main impacts, which allows everyone to assess risk and mitigate possible influences,” L’Heureux said.
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