GFS vs JMA
NOAA GFS (American model) and JMA GSM (Japanese model) are independent forecasts built by different weather services. GFS: Frequent updates, long range, US convective detail when blended with HRRR. 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.
| NOAA GFS | JMA GSM | |
|---|---|---|
| Run by | NOAA / National Centers for Environmental Prediction | Japan Meteorological Agency |
| Origin | United States | Japan |
| Resolution | ~13 km (blended with HRRR 3 km over the US) | ~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 16 days | up to 11 days |
| Type | Physics-based NWP | Physics-based NWP |
| Also called | American model, Global Forecast System | Japanese model, GSM, MSM |
| Strengths | Frequent updates, long range, US convective detail when blended with HRRR. | Typhoon tracks and East Asian monsoon patterns; MSM detail over Japan. |
| Weaknesses | More run-to-run swings than ECMWF in the medium range; can over-deepen distant lows. | Coarse open-data grid misses local effects; no wind-gust output. |
Key differences
- GFS resolution: ~13 km (blended with HRRR 3 km over the US); JMA: ~55 km open data global; 5 km MSM over Japan.
- GFS range: about 16 days; JMA: about 11 days.
- GFS updates: 4 per day (00, 06, 12, 18 UTC); JMA: 4 per day.
- GFS weak spots: More run-to-run swings than ECMWF in the medium range; can over-deepen distant lows. JMA weak spots: Coarse open-data grid misses local effects; no wind-gust output.
Questions
Is GFS or JMA more accurate?
NOAA GFS (American model) and JMA GSM (Japanese model) are independent forecasts built by different weather services. GFS: Frequent updates, long range, US convective detail when blended with HRRR. 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 GFS and JMA side by side?
On every MeteoStack city page: the stack shows GFS, 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