Meteocat flags possible early El Niño effects as NOAA declares super event

Pacific warming crosses the official threshold

The Climate Prediction Center at NOAA announced on Thursday, 12 November, that El Niño had reached the level needed for designation. Pacific waters have stayed at least 0.5 degrees Celsius above average for three consecutive months, and the pattern has been active since late spring. The agency expects the event to keep strengthening, with a strong-to-very strong episode likely between January and March 2027. Reporting on the announcement says this year's event may be among the strongest ever, with ocean heat partly fed by human-caused climate change. The last time the phenomenon was this strong was 1877, a year when a global famine killed more than 50 million people.

NOAA's own wording on the strengthening was plain:

“El Niño continues to strengthen, with a strong-to-very strong El Niño likely through January-March 2027.”

Two early signals reach Catalonia

Meteocat has identified two atmospheric signals that could be early links between El Niño and the Iberian Peninsula. The first is a possible weakening of the polar vortex, which the service considers relevant because changes could travel down into lower layers and shift North Atlantic circulation and the North Atlantic Oscillation. The second is an atmospheric river carrying tropical moisture into the region in the week of 9 November, associated with the storm Charles. Vicent Altava, a Meteocat research technician, said the signals match two physical mechanisms through which a strong episode can influence the North Atlantic, but he cautioned about causation.

“However, it cannot yet be established that they are a direct consequence of the phenomenon.”

Moisture corridor and storm pattern

Maps of the flow show a humid corridor stretching from Cuba toward Portugal, which carried the storm to the Atlantic coast of the Peninsula. Toni Barrera, a climate change technician at Meteocat, said the subtropical jet has been strengthened by the active super El Niño as of 13 November. Southwesterly winds usually favour the western part of Catalonia and the south side of the Pyrenees, and a repeat of this circulation over the coming months could bring more rain than forecast. Barrera stressed that this outlook is long-range and uncertain, and that it matches the seasonal forecast.

Rain, cold air and temperatures in Catalonia

Sarai Sarroca, Meteocat's director, said storm Charles was an example of El Niño effects reaching the region. By the time it approached Catalonia, the rain had weakened, falling mostly on the south side of the Pyrenees and the pre-Pyrenees, while wind and rough seas were also recorded. Looking ahead, Meteocat expects abundant rain on the south face of the Pyrenees and a lower chance of short cold-air incursions, against a backdrop of temperatures above normal through the rest of 2026 and in 2027. Before the episode strengthened, Meteocat had ruled out effects in the region, but recent observations show the phenomenon reaching areas where it normally does not.

Across the Atlantic, Ben Knoll, a meteorologist, said on social media on Thursday, 12 November, that this El Niño winter could bring 19 strong East Coast storms, against a normal of nine according to ECMWF.

El Niño winter forecast (ECMWF)19

Normal (ECMWF)9

El Niño winter forecast (ECMWF)

19

Normal (ECMWF)

9

Data from the article text

In the southern United States, the pattern has already brought flooding, and further impacts are expected through spring.

Open questions on scale and duration

Meteocat says no attribution studies yet exist for El Niño's effects in Catalonia, even though the episode is very intense in its central Pacific zone. The service cannot say whether the effects will bring heavy rain, drought or only minor changes. Model estimates put the anomaly between 3.4 and 4 degrees Celsius above average, while Barrera said sea-surface anomalies in the central and eastern Pacific currently exceed 3 degrees. Forecasts show warming continuing until December and January 2027, before easing toward April and May.