Winter 2026/2027 First Forecast: Super El Niño Drives a Major Weather Divide

In this first in-depth Winter 2026/2027 forecast, I break down the latest ocean data, historical Super El Niño winter patterns, the latest temperature and snowfall predictions, early Polar Vortex weakening signals, and the month-to-month evolution across the United States, Canada, and Europe.

Super El Niño 2026: Ocean Heat Builds Ahead of Winter We are continuing to track the development of a Super El Niño event that is already a major global weather driver. This Super El Niño is on a strong trajectory, with the forecasts continuing to keep it well within a Super to Extreme event threshold. Below you can see the atmospheric changes that an El Niño brings, changing the overall global circulation. The upward and downward atmospheric motion and circulation in the tropical regions is called a Walker Cell, and is especially sensitive to strong ENSO events (El Niño or La Niña). Image by ESA. To keep it simple, El Niño lowers atmospheric pressure in the central and eastern tropical Pacific while building high pressure over the west parts. This shift launches atmospheric wave trains across both hemispheres, directly reshaping global jet streams, precipitation, and seasonal weather patterns. El Niño events occur every few years, but Super events are rare, occurring once per decade or less, usually with strong atmospheric impacts. I base my El Niño analysis on NOAA-CRW data. In the latest data below, you can see substantial warm anomalies continuing, with values exceeding 6°C (11°F) above normal over a large area. This is a really strong anomaly at this phase of development, already reaching into Super El Niño territory. This growth is also confirmed by the latest analysis graph below for the main ENSO region from OISST. We can see a rapid, continuous anomaly increase, with El Niño on a rapid growth trajectory. There is a slight break currently, but this is normal and expected, with forecasts still showing several months of growth ahead. To be classified as a Super El Niño event, sustained seasonal values must exceed +2 degrees, which we have already exceeded. So we just need to sustain this on a seasonal scale, which should not be hard to do, given the powerful core of this event and the latest forecasts. Below you can see the real core (heart) of this Super El Niño event: a significant subsurface temperature anomaly in the top 250m (800ft) of the tropical Pacific. This is a so-called downwelling Kelvin Wave, with peak anomalies over 9 degrees (16°F) above normal, being the engine and core of this event. In the west, a rising cold anomaly (blue) is visible below 50 meters (164ft), and no, it does not mean an early end for El Niño. It actually marks the classic tilting of the Pacific thermocline, signaling an extreme event. Strong westerly wind bursts displace warm upper-ocean waters eastward into the Kelvin Wave, pulling colder, deeper water up in the west as the Super El Niño strengthens. Below is a video I produced from subsurface ocean data. It shows the development of a Kelvin Wave over the past 90 days, with visible eastward movement and rapid growth. You can also see how it expands, giving rise to a Super El Niño in the eastern parts. Ocean surface anomalies are just the visible surface signature of this large subsurface warm-core anomaly that slowly surfaces. It provides a continuous supply of energy to keep the El Niño strong and healthy well into the Winter season, which the latest forecasts also indicate. Super El Niño Forecast: Models Push Toward Record Strength Most seasonal forecast systems simulate the ocean along with the atmosphere. Since seasonal models cannot properly predict individual wind bursts and Kelvin waves until they start occurring, each monthly update must adjust to new data. As a result, the models have steadily raised the peak strength of this Super El Niño with each new forecast run. This has created a very strong visual forecast trend, with each new forecast showing a stronger peak El Niño anomaly. Below is a comparison I produced using the most recent ECMWF forecasts, released since early February. You can clearly see that each new run shows a stronger event, with the last three runs pushing it into record-strong territory, above the strongest Super El Niño events. In the image below, we can also see the NCEP CFSv2 model forecast, which shows the fully released Kelvin Wave at peak. The El Niño is forecast to reach extreme levels, surpassing the Super El Niño threshold (+2 degrees), and also exceeding the +3 anomaly. Both forecast systems agree on a historic El Niño development and influence on Winter 2026/2027. To give you an idea of how this looks in nature, you can see the ECMWF forecast below for the November-December period. It reveals a significant Super El Niño event. If the projected basin-wide ENSO strength verifies, the 2026 event would rank among the strongest on record, if not the strongest. El Niño events always peak later in the year, with the latest forecasts trending toward a max anomaly around November-December, as seen above. This is primed for atmospheric Winter impacts for 2026/2027. We can look at the past Super El Niño Winters to get an idea of what winter weather impacts we can expect from such a powerful event. Past Super El Niño Winters: Pressure, Temperature and Snowfall Patterns As we get to Winter El Niño impacts, the strength of the event really starts to matter. The schematic below (by Raganato et al.) shows how strong tropical forcing creates a planetary wave train in upper levels as winter begins. Strong ocean anomalies and the massive energy of a Super El Niño create an atmospheric domino effect that spreads across the entire Northern Hemisphere during the cold-weather season. This pressure wave train acts like a giant atmospheric highway, creating a repeating chain of high and low-pressure systems around the globe. The result is a deep low-pressure trough over the North Pacific, forcing a strong ridge over Canada and driving another low-pressure zone over the southern U.S. and into the Atlantic. While a moderate event produces a mild wave pattern, a Super El Niño usually triggers a far more aggressive shift in the jet stream. The transition from a Moderate to an Extreme El Niño leads to a deeper Pacific trough and a stronger Canadian ridge, forming an atmospheric highway across the United States. The image is from a recent study (linked below). It’s hard to find anything in the past data to compare to the 2026 event and Winter impacts. But we can still look at the last 4 Super El Niño events and how the average Winter looked in those seasons. I produced graphics showing pressure, temperature, and snowfall patterns for Winters in these Super El Niño events. The pressure analysis is the most telling, as it shows the average positioning of the pressure systems across these four events. We can see a strong atmospheric wave train forced by the Super El Niño events. The main feature is the deep, intense low-pressure anomaly over the North Pacific, reflecting an expanded Aleutian Low. Such a deep low forces a massive high-pressure ridge over Canada, the northern U.S., and the Great Lakes, forcing the jet stream to split. This keeps the coldest air deflected away from the northern parts with an active storm track across the southern United States. Downstream, this favors lower pressure over the North Atlantic and a milder westerly flow across most of mainland Europe. The temperature analysis below visually tells this story, showing the average winter (December–February) temperature anomalies across past Super El Niño events.

But the active subtropical jet stream keeps temperatures cooler across the southern United States, due to persistent cloud cover and precipitation. Over Europe, the dominant westerly flow drives above-average temperatures across most of the continent. Pressure, temperature, and moisture changes also shape the snowfall pattern. Below is a composite I produced from ERA5 data, showing average winter snowfall anomalies in the past 4 Super El Niño events.