ECMWF vs JMA
ECMWF IFS (European model) and JMA GSM (Japanese 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. JMA: Typhoon tracks and East Asian monsoon patterns; MSM detail over Japan. Neither is right every time: the useful signal is whether they agree. Compare them live below for any city.
| ECMWF IFS | JMA GSM | |
|---|---|---|
| Run by | European Centre for Medium-Range Weather Forecasts | Japan Meteorological Agency |
| Origin | Europe | Japan |
| Resolution | 9 km (IFS HRES) | ~55 km open data global; 5 km MSM over Japan |
| Model runs | 4 per day (00, 06, 12, 18 UTC) | 4 per day |
| Forecast range | up to 15 days | up to 11 days |
| Type | Physics-based NWP | Physics-based NWP |
| Also called | European model, Euro, IFS, ECMWF HRES | Japanese model, GSM, MSM |
| Strengths | Large-scale pattern and storm track 3–10 days out, pressure systems, medium-range temperature. | Typhoon tracks and East Asian monsoon patterns; MSM detail over Japan. |
| Weaknesses | A 9 km grid still smooths narrow valleys and coastlines; convective showers are parameterised, not resolved. | Coarse open-data grid misses local effects; no wind-gust output. |
Key differences
- ECMWF resolution: 9 km (IFS HRES); JMA: ~55 km open data global; 5 km MSM over Japan.
- ECMWF range: about 15 days; JMA: about 11 days.
- ECMWF updates: 4 per day (00, 06, 12, 18 UTC); JMA: 4 per day.
- ECMWF weak spots: A 9 km grid still smooths narrow valleys and coastlines; convective showers are parameterised, not resolved. JMA weak spots: Coarse open-data grid misses local effects; no wind-gust output.
Questions
Is ECMWF or JMA more accurate?
ECMWF IFS (European model) and JMA GSM (Japanese 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. JMA: Typhoon tracks and East Asian monsoon patterns; MSM detail over Japan. 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 JMA side by side?
On every MeteoStack city page: the stack shows ECMWF, JMA 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