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Models and monthly initializations
Seasonal forecast comparison
Compare seasonal forecasts from ECMWF, the UK Met Office, Météo-France, DWD and CMCC. Synchronized maps use a common valid period and colour scale to support comparison across models and monthly initializations.
Comparison methods
- Across models
- Compare up to four seasonal models initialized in the same month, with all panels aligned to one valid period.
- Across initializations
- Compare successive monthly runs from one model to assess changes in the forecast for a common target period.
- Variables
- 2 m temperature, precipitation, mean sea-level pressure and sea-surface temperature.
- Forecast products
- Ensemble-mean anomalies, tercile summaries, median exceedance, lower, middle and upper tercile probabilities, and lowest and highest quintile probabilities.
- Valid periods
- Monthly means at six lead times and four overlapping three-month windows per initialization, subject to availability across the selected runs.
Selected comparisons
- ECMWF, UK Met Office, Météo-France and DWD: January 2027 temperature over Europe
Four ensemble-mean anomalies from the October 2026 runs on one colour scale.
- ECMWF September 2026 vs October 2026 run for January 2027
The same target month from two successive initializations.
- Sea-surface temperature, global view, four models for February 2027
Compare projected sea-surface temperature anomalies across ocean basins.
The maps use operational seasonal forecast data from the Copernicus Climate Change Service (C3S). Anomalies are referenced to each system’s own 1993–2016 hindcast climatology. Probabilities are calculated from forecast ensemble members and matching hindcasts.
Fields are displayed on a 1° grid. Selecting a location reports the source-grid value in each panel. The forecast guide explains the reference periods, probability categories and interpretation of each product.