ECMWF vs GFS
ECMWF is usually more accurate than GFS, especially from day 3 to day 10: in independent verification of 500 hPa height scores the European model has led the American model for most of the last two decades. GFS updates four times a day and is free at higher resolution, so it is excellent for spotting trends, but when the two disagree beyond a few days, ECMWF is right more often. The best approach is to look at both, plus other models, and trust the forecast more when they agree.
| ECMWF IFS | NOAA GFS | |
|---|---|---|
| Run by | European Centre for Medium-Range Weather Forecasts | NOAA / National Centers for Environmental Prediction |
| Origin | Europe | United States |
| Resolution | 9 km (IFS HRES) | ~13 km (blended with HRRR 3 km over the US) |
| Model runs | 4 per day (00, 06, 12, 18 UTC) | 4 per day (00, 06, 12, 18 UTC) |
| Forecast range | up to 15 days | up to 16 days |
| Type | Physics-based NWP | Physics-based NWP |
| Also called | European model, Euro, IFS, ECMWF HRES | American model, Global Forecast System |
| Strengths | Large-scale pattern and storm track 3–10 days out, pressure systems, medium-range temperature. | Frequent updates, long range, US convective detail when blended with HRRR. |
| Weaknesses | A 9 km grid still smooths narrow valleys and coastlines; convective showers are parameterised, not resolved. | More run-to-run swings than ECMWF in the medium range; can over-deepen distant lows. |
Key differences
- Accuracy: ECMWF IFS leads in global verification scores; NOAA upgrades (GFS v16, v17) narrowed but did not close the gap.
- Resolution: ECMWF IFS HRES runs on a 9 km grid, GFS at about 13 km.
- Range: GFS goes to 16 days, ECMWF open data to 15 days. Beyond about 10 days neither is reliable on details.
- Typical biases: GFS can be too fast or too deep with distant lows and often flips between runs; ECMWF can be slightly too smooth with convective rain.
- Hurricanes: both are top-tier for tracks; for intensity, specialised models (HAFS, HWRF) are better than either.
Questions
Is ECMWF or GFS more accurate?
ECMWF is usually more accurate than GFS, especially from day 3 to day 10: in independent verification of 500 hPa height scores the European model has led the American model for most of the last two decades. GFS updates four times a day and is free at higher resolution, so it is excellent for spotting trends, but when the two disagree beyond a few days, ECMWF is right more often. The best approach is to look at both, plus other models, and trust the forecast more when they agree.
Which is the European model and which is the American model?
The "European model" is ECMWF (IFS, and its AI sibling AIFS). The "American model" is NOAA's GFS. The German model is ICON, the Canadian model GEM, the UK model UKMO and the French models ARPEGE/AROME.
Where can I see ECMWF and GFS side by side?
On every MeteoStack city page: the stack shows ECMWF, GFS and up to ten other models hour by hour, with their median consensus, spread and rain odds. It is free and works for any place on Earth.
More comparisons
ECMWF vs GFS · ECMWF vs ICON · GFS vs ICON · ECMWF vs AIFS · ECMWF vs UKMO · GFS vs GEM · ECMWF vs GEM · ICON vs ARPEGE · GFS vs AIFS · UKMO vs GFS · ECMWF vs JMA · ICON vs UKMO · ECMWF vs ARPEGE · GFS vs JMA