ECMWF vs ARPEGE
ECMWF IFS (European model) and Météo-France ARPEGE / AROME (French model) are independent forecasts built by different weather services. ECMWF: Large-scale pattern and storm track 3–10 days out, pressure systems, medium-range temperature. ARPEGE: Convective rain, Mediterranean "épisodes cévenols", wind in complex terrain. Neither is right every time: the useful signal is whether they agree. Compare them live below for any city.
| ECMWF IFS | Météo-France ARPEGE / AROME | |
|---|---|---|
| Run by | European Centre for Medium-Range Weather Forecasts | Météo-France |
| Origin | Europe | France |
| Resolution | 9 km (IFS HRES) | ~25 km world, 10 km Europe, 1.3 km AROME over France |
| Model runs | 4 per day (00, 06, 12, 18 UTC) | 4 per day |
| Forecast range | up to 15 days | up to 4 days |
| Type | Physics-based NWP | Physics-based NWP |
| Also called | European model, Euro, IFS, ECMWF HRES | French model, ARPEGE, AROME |
| Strengths | Large-scale pattern and storm track 3–10 days out, pressure systems, medium-range temperature. | Convective rain, Mediterranean "épisodes cévenols", wind in complex terrain. |
| Weaknesses | A 9 km grid still smooths narrow valleys and coastlines; convective showers are parameterised, not resolved. | Short range (about 4 days); global ARPEGE is less skilful than ECMWF. |
Key differences
- ECMWF resolution: 9 km (IFS HRES); ARPEGE: ~25 km world, 10 km Europe, 1.3 km AROME over France.
- ECMWF range: about 15 days; ARPEGE: about 4 days.
- ECMWF updates: 4 per day (00, 06, 12, 18 UTC); ARPEGE: 4 per day.
- ECMWF weak spots: A 9 km grid still smooths narrow valleys and coastlines; convective showers are parameterised, not resolved. ARPEGE weak spots: Short range (about 4 days); global ARPEGE is less skilful than ECMWF.
Questions
Is ECMWF or ARPEGE more accurate?
ECMWF IFS (European model) and Météo-France ARPEGE / AROME (French model) are independent forecasts built by different weather services. ECMWF: Large-scale pattern and storm track 3–10 days out, pressure systems, medium-range temperature. ARPEGE: Convective rain, Mediterranean "épisodes cévenols", wind in complex terrain. Neither is right every time: the useful signal is whether they agree. Compare them live below for any city.
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 ARPEGE side by side?
On every MeteoStack city page: the stack shows ECMWF, ARPEGE 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