GFS vs AIFS
NOAA GFS (American model) and ECMWF AIFS (ECMWF AI model) are independent forecasts built by different weather services. GFS: Frequent updates, long range, US convective detail when blended with HRRR. AIFS: Very competitive large-scale skill, notably tropical cyclone tracks; fast and consistent run-to-run. Neither is right every time: the useful signal is whether they agree. Compare them live below for any city.
| NOAA GFS | ECMWF AIFS | |
|---|---|---|
| Run by | NOAA / National Centers for Environmental Prediction | European Centre for Medium-Range Weather Forecasts |
| Origin | United States | Europe |
| Resolution | ~13 km (blended with HRRR 3 km over the US) | 0.25° (~28 km), 6-hourly steps |
| Model runs | 4 per day (00, 06, 12, 18 UTC) | 4 per day |
| Forecast range | up to 16 days | up to 15 days |
| Type | Physics-based NWP | Machine learning |
| Also called | American model, Global Forecast System | ECMWF AI model, Artificial Intelligence Forecasting System |
| Strengths | Frequent updates, long range, US convective detail when blended with HRRR. | Very competitive large-scale skill, notably tropical cyclone tracks; fast and consistent run-to-run. |
| Weaknesses | More run-to-run swings than ECMWF in the medium range; can over-deepen distant lows. | Tends to smooth extremes; rain intensity and local detail are less reliable than its pattern. Output is 6-hourly, without gusts. |
Key differences
- GFS resolution: ~13 km (blended with HRRR 3 km over the US); AIFS: 0.25° (~28 km), 6-hourly steps.
- GFS range: about 16 days; AIFS: about 15 days.
- GFS updates: 4 per day (00, 06, 12, 18 UTC); AIFS: 4 per day.
- GFS weak spots: More run-to-run swings than ECMWF in the medium range; can over-deepen distant lows. AIFS weak spots: Tends to smooth extremes; rain intensity and local detail are less reliable than its pattern. Output is 6-hourly, without gusts.
Questions
Is GFS or AIFS more accurate?
NOAA GFS (American model) and ECMWF AIFS (ECMWF AI model) are independent forecasts built by different weather services. GFS: Frequent updates, long range, US convective detail when blended with HRRR. AIFS: Very competitive large-scale skill, notably tropical cyclone tracks; fast and consistent run-to-run. 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 AIFS side by side?
On every MeteoStack city page: the stack shows GFS, AIFS 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