A rapidly strengthening El Niño could reshape weather patterns across the United States in the coming months, increasing the likelihood of extreme rainfall, drought and record-breaking heat as the natural climate phenomenon combines with a warming planet.
A rapidly strengthening El Niño could reshape weather patterns across the United States in the coming months, increasing the likelihood of extreme rainfall, drought and record-breaking heat as the natural climate phenomenon combines with a warming planet.
But climate scientist Daniel Swain says the forecast should be viewed as a reason to prepare — not panic.
During an American Community Media national news briefing, Swain said temperatures in a key region of the eastern tropical Pacific Ocean were already at record levels for this time of year, while forecasting models showed El Niño continuing to strengthen into the fall.
While the phrase “Super El Niño” has become increasingly common, Swain said it is not an official scientific classification. Instead, it is generally used to describe a very strong El Niño.
This year’s forecast, however, is unusual even by those standards.
“I would suggest maybe we need a new category of extreme El Niño, because the forecast for this year is genuinely extreme,” Swain said.
El Niño is a naturally occurring climate pattern involving unusually warm water in the eastern and central tropical Pacific Ocean. That warming changes atmospheric circulation and can shift storm tracks, affecting weather thousands of miles away. Swain described the distant impacts as similar to ripples spreading after a pebble is dropped into a pond.
NOAA similarly defines El Niño as the warm phase of the El Niño-Southern Oscillation, or ENSO, in which above-average Pacific sea-surface temperatures interact with the atmosphere and influence weather patterns around the world.
This year’s event is especially significant because it is occurring against the backdrop of human-caused climate change.
Swain explained that El Niño temporarily releases stored heat from the tropical ocean into the atmosphere. When that natural warming is layered on top of long-term global warming, temperatures can climb even higher.
He said the combination is expected to bring a new round of record global temperatures over the next six to 12 months, accompanied by increased chances of extreme rainfall, drought and wildfire in different regions.
Swain did not provide a Houston-specific winter forecast during the briefing, and El Niño’s effects can vary considerably from one region to another.
However, the broader pattern has implications for the southern United States. NOAA notes that El Niño typically favors wetter winter conditions across the southern tier of the country.
Swain said the southeastern United States is likely to experience a very wet winter this year, potentially increasing flood risk while providing some relief to areas experiencing drought.
Farther west, he said the Lower Colorado River Basin could receive average to above-average precipitation. Even an exceptionally wet winter, however, would provide only temporary relief from the region’s long-term water challenges.
“Nothing that could plausibly happen in the next year could really reverse the broader trajectory,” Swain said, pointing to climate change, long-term aridification and demand for water that already exceeds supply.
For Texans, the broader takeaway is not that El Niño guarantees a particular storm or flood. Rather, an exceptionally strong event can tilt the odds toward certain weather patterns while leaving considerable uncertainty about exactly where individual extremes will occur.
One of Swain’s strongest preparedness messages involved flooding.
Communities built in flood-prone areas face growing risks as heavy downpours become more intense, he said. And for homeowners, the physical threat can be compounded by financial exposure.
Swain noted that many Americans living in high-risk flood areas do not have flood insurance and may not realize that standard property insurance typically does not include flood coverage.
For those able to obtain it, he said this could be a good year to examine whether flood insurance makes sense.
That message carries particular resonance in Greater Houston, where residents are familiar with the consequences of extreme rainfall and flooding.
The lesson is less about predicting the next storm than understanding personal risk before the water begins to rise.
El Niño’s effects are not limited to property and infrastructure.
Swain said both severe drought and flooding can increase the risk of waterborne illnesses, particularly in communities without consistent access to reliable treated water.
While public water systems reduce much of that risk in the United States, he identified rural communities and Tribal lands among places where disruptions can pose greater concerns.
Heat presents another challenge.
Warmer ocean temperatures can contribute to more humid conditions, reducing the body’s ability to cool itself through sweating. Swain said that can increase health risks during heat waves, particularly for people without air conditioning and when overnight temperatures remain warm.
El Niño is expected to reach peak strength sometime between October and December, with November near the center of Swain’s forecast window.
But the most significant impacts outside the tropics are expected to lag behind the event itself, potentially emerging from December through March or even later in some areas.
That delay provides something valuable: time.
Swain emphasized during the briefing that many potential consequences are neither completely unpredictable nor impossible to reduce through preparation.
And he cautioned journalists and the public against allowing dramatic headlines to turn a serious climate event into an inevitable catastrophe.
The developing El Niño is potentially historic, he said, and some places could experience significant consequences. But communities also have an opportunity to prepare before those impacts arrive.
“We can’t prevent El Niño, but we can prepare, hopefully successfully, to mitigate its impacts by putting measures into place to make those impacts less consequential,” Swain said.
For Texans accustomed to weather that can swing from drought to downpour, that may be the most useful forecast of all: pay attention now, understand the risks and use the advance warning to prepare.
