The transition into meteorological summer 2026 is being defined by a rapid warming of the tropical Pacific Ocean. Latest analysis reveals a significant subsurface Kelvin wave surfacing in the eastern Pacific, signalling the onset of what forecasters describe as a potentially record-strong Super El Niño event. The intensifying warm phase is reorganising global atmospheric circulation and shifting the planetary jet stream, with the first major impacts expected across North America and Europe as early as the first half of summer.
Forecasters from the U.S. National Oceanic and Atmospheric Administration's Climate Prediction Center are expected to declare El Niño underway imminently, while the United Nations World Meteorological Organization puts the likelihood of El Niño starting this summer at about 80%, rising to near or above 90% through November. Sea surface temperatures in the main El Niño monitoring region have already climbed to record levels for the date, warming nearly a full degree Fahrenheit in early June alone.
What is ENSO and a Super El Niño?
El Niño–Southern Oscillation, or ENSO, is a natural climate cycle in the tropical Pacific that alternates between warm El Niño phases, cool La Niña phases and neutral conditions every two to seven years. During El Niño, trade winds weaken and warm surface waters spread across the central and eastern Pacific, altering rainfall and pressure patterns worldwide through what scientists call an atmospheric bridge.
The upward and downward motion of air in the tropics — known as the Walker Cell — is especially sensitive to strong ENSO events. A warm ocean anomaly in the eastern and central tropical Pacific is accompanied by lower pressure over the Pacific and higher pressure over the western Pacific, sending ripples through the global weather system.
A Super El Niño is not an official NOAA category, but the term is widely used when sea surface temperature anomalies in the Niño 3.4 region exceed +2.0°C (+3.6°F) above the long-term average for several months. Only a handful of such events have occurred since 1950; the most recent peaked in 2015–2016, when ocean anomalies exceeded +3°C (+5.4°F) and left a vast warm signature across the equatorial Pacific.
Ocean analysis: the 2026 Kelvin wave
Ocean data for the past ten months show a weak La Niña through the fall and winter of 2025–26, followed by a sharp reversal. Warm anomalies are now building across the tropical Pacific, with the strongest readings in the eastern basin where abnormally warm subsurface waters are rising to the surface, already reaching about +2°C (+3.6°F) in that region.
Subsurface temperature anomalies in the top 300 metres (984 ft) of the tropical Pacific reveal a powerful warm core — a Kelvin wave — being pushed eastward by weaker trade winds and westerly wind bursts. At this stage of development, the 2026 event is on par with the last two Super El Niños of 1997–98 and 2015–16, and is currently warmer in the western tropical Pacific than either of those events at the same point, suggesting the warm supply from the west has not yet fully discharged.
Seasonal forecast models are tracking a strengthening trend with each successive update. The NCEP CFSv2, ECMWF extended range and the North American NMME ensemble all show a very strong El Niño developing, with peak Niño 3.4 values potentially approaching +3°C (+5.4°F) and local anomalies exceeding +4°C (+7.2°F) — rivalling the strongest events in the historical record.
First atmospheric signals
With El Niño intensifying rapidly, clear atmospheric fingerprints are already emerging. The July 2026 velocity-potential forecast shows a strong anomaly of rising air over the central and eastern tropical Pacific and sinking air over the Indian Ocean — a textbook El Niño Walker Cell configuration that confirms the warm ocean phase is coupling with the atmosphere this summer.
El Niño also alters the polar and Pacific jet streams. A stronger, eastward-extended Pacific jet typically brings increased moisture to the western and southern United States, while the polar jet can dip farther south over eastern Canada, influencing temperature and storm tracks across the continent.
United States and Canada summer outlook
Analysis of past developing Super El Niño summers shows a tendency for below-normal temperatures across the Midwest, the eastern and central United States, and eastern Canada, with warmer conditions prevailing in the west and south. Precipitation anomalies feature a corridor of increased rainfall over the western and southwestern United States extending eastward, while the far southern U.S., the Gulf Coast, the Northern Plains and southern Canada tend to be drier.
The latest Copernicus multi-model summer 2026 forecast mirrors this rainfall pattern. Temperature forecasts show broadly above-normal summer readings, but the underlying flow pattern — a more northerly stream over eastern Canada and the eastern United States with a strengthening Pacific jet in the west and south — aligns with historical Super El Niño summers. ECMWF extended-range forecasts for June 2026 show a clearer picture, with cooler-than-normal conditions expanding from the northwest into the northern and eastern U.S.
Increased rainfall in the Colorado Basin and southern Plains could offer partial relief to drought-affected areas in the West, though forecasters caution it will not be enough to erase long-term water deficits. Houston and the broader Gulf region may see variable moisture as the shifted jet stream redistributes rainfall.
Hail and tornado frequency shifts
When El Niño alters jet stream and pressure patterns, it directly affects thunderstorm development during the summer months. Historical analysis of developing Super El Niño summers shows a notable increase in hail reports across the west-central and Northern Plains, the Intermountain West, the Southwest and Florida, while much of the Northeast and Gulf Coast sees decreased hail activity.
States with potential for increased hail events include Colorado, Wyoming, Nebraska, Kansas, Oklahoma, northern Texas, Florida, Georgia, South Carolina and North Carolina. States that may see decreased hail include Pennsylvania, New York, New Jersey, Maryland, Virginia, Louisiana, Mississippi, Alabama and Arkansas. Denver and the central Rockies sit within the zone of elevated hail risk.
Tornado activity also shifts. Florida and parts of the west-central Plains show a visible increase in tornadic reports, while a broad area of the Midwest, Ohio Valley and southern United States experiences suppression. The active storm corridors tighten, with tornadic potential becoming more localised rather than widespread across traditional Tornado Alley regions. Florida shows the most significant tornado anomaly, with increases also indicated for Colorado, western Kansas, western Nebraska, the Oklahoma and Texas Panhandles and New Mexico.
Europe summer outlook
During past developing Super El Niño summers, central and northern Europe tended toward above-normal temperatures, while western and southeastern areas were more variable. Precipitation analysis shows increased rainfall across the southern half of the continent and southern UK, with drier conditions over northern Europe associated with a high-pressure anomaly to the north and low pressure over the southwest.
The Copernicus summer 2026 ensemble shows a similar core of warmer anomalies over central Europe, with increased rainfall over southern areas consistent with historical patterns. Forecasts also indicate drought risk across central, north-central and east-central Europe as the drier signal shifts southward compared with past events.
Storm-energy analysis using CAPE — the potential energy available for thunderstorms — shows increased instability across the southern half of Europe during Super El Niño summers, with elevated wind shear over southern regions creating a supportive environment for organised storms. Western and north-central areas see below-normal shear, which can limit severe storm potential despite higher energy.
London and the UK may see variable summer temperatures under this pattern, while Paris and central Europe face elevated storm potential alongside drought risk in surrounding areas.
Broader global impacts
Beyond North America and Europe, El Niño releases heat stored in the Pacific into the atmosphere, temporarily pushing global air temperatures higher on top of long-term climate warming. Experts warn that 2026 and 2027 could challenge recent temperature records. The Atlantic hurricane season is typically quieter during El Niño years because increased wind shear disrupts storm organisation in the Caribbean and tropical Atlantic; AccuWeather now leans toward about 11 named storms rather than a busier season. However, forecasters stress that coastal communities should not be complacent — homegrown storms near the coastline leave little time for preparation.
Conversely, tropical cyclone activity tends to increase in the eastern and central Pacific, affecting Mexico, Central America and parts of the western Americas. El Niño also disrupts monsoon rainfall in parts of South and Southeast Asia, affects maize, rice and wheat yields in major producing regions, and reduces nutrient upwelling that supports fisheries from Peru and Ecuador to California and Mexico. The impacts are unevenly distributed, with the strongest effects often felt in tropical and developing regions.
Track summer weather on SatMeteo
As a potentially historic Super El Niño reshapes jet stream patterns and storm corridors across North America and Europe, staying ahead of shifting conditions matters. Check hourly and extended forecasts for your area on SatMeteo, use the live temperature map to monitor heat building across continents in real time, and follow outlooks for Miami and the southeastern United States where early storm signals are already emerging.
