Full Breakdown
Potential Super El Niño Threatens 2026-27 Winter Weather
8/19/2026, 11:09:37 AM
Core Forecast: Record-Strength El Niño Expected
NOAA’s Climate Prediction Center (CPC) now gives a 95 % chance of a very strong El Niño for October–December, 90 % for November–January and 70 % for December–February. Its forecast places the median October–December sea-surface temperature anomaly at +2.66 °C (? +4.8 °F), with the middle 50 % ranging from +2.37 °C to +2.95 °C. For December–February the median is +2.23 °C (+4 °F), approaching the “Super El Niño” threshold of +2 °C for three consecutive months.
Background & Context
El Niño is a periodic warming of equatorial Pacific waters. Past “Super” events (1982-83, 1997-98, 2015-16, 1877-78) showed anomalies above +2 °C for multiple months. The 2026 event already shows +1.4 °C in the Niño-3.4 region and +2.9 °C in Niño-1+2, with subsurface warming up to +10 °C in localized pockets.
Data & Statistics
| Metric | Value | Source |
|---|---|---|
| Probability (Oct-Dec) | 95 % | NOAA CPC (August) |
| Probability (Nov-Jan) | 90 % | NOAA CPC (August) |
| Probability (Dec-Feb) | 70 % | NOAA CPC (August) |
| Median RONI (Oct-Dec) | +2.66 °C (+4.8 °F) | NOAA CPC (August) |
| Median RONI (Dec-Feb) | +2.23 °C (+4 °F) | NOAA CPC (August) |
| Niño-3.4 anomaly (July) | +1.4 °C (+2.5 °F) | NOAA CPC (July) |
| Niño-1+2 anomaly (July) | +2.9 °C (+5.2 °F) | NOAA CPC (July) |
| BoM Niño-3.4 (week ending Aug 9) | +2.20 °C (+4 °F) | BoM |
| JMA Niño-3 (July) | +2.5 °C (+4.5 °F) | JMA |
| Indian Ocean Dipole (week ending Aug 9) | +0.41 °C (+0.7 °F) | BoM |
| Southern Oscillation Index (July) | –29.1 | BoM |
Official Statements & Responses
- The Bureau of Meteorology noted the July upper-ocean heat anomaly as the highest since its 1979 record began.
- Japan’s Meteorological Agency linked its July Niño-3 anomaly to the 1997 event, the strongest July value in its record.
- The UK Met Office warned that El Niño can raise the chance of a windy, mild start to a UK winter and a colder end, but other modes such as the North Atlantic Oscillation will also play a role.
Expected Impacts on Europe and Other Regions
- The C3S August 10 update (autumn focus) shows wetter-than-average signals for southern and western Europe, with higher uncertainty for winter.
- Severe Weather Europe’s ECMWF interpretation suggests above-normal winter temperatures across large parts of Europe, lower snowfall in low-elevation areas and higher snowfall in northern, northeastern, and mountainous regions.
- The UK Met Office’s outlook highlights a possible mild, windy early winter followed by a colder later phase, contingent on the North Atlantic Oscillation and jet-stream positioning.
Conflicting Reports & Gaps
- Agencies use different indices (NOAA’s RONI, BoM’s Niño-3.4, JMA’s Niño-3) that are not directly comparable.
- While CPC emphasizes a high chance of a “very strong” event, ensemble spread shows less extreme outcomes remain possible.
- The influence of concurrent Indian Ocean warming and a nascent Indian Ocean Dipole on North American teleconnections is still uncertain.
What’s Next
- CPC’s next U.S. seasonal outlook: August 20.
- ENSO Diagnostic Discussion from NOAA/CPC: August 13, 2026.
- Ongoing monitoring by the Bureau of Meteorology, Japan Meteorological Agency, and the European Centre for Medium-Range Weather Forecasts will refine the forecast in the coming months.
