Weather models
Weather forecast models, explained
Every forecast you read comes from a numerical weather prediction (NWP) model — a physics simulation of the atmosphere run on a supercomputer. No single model is right all the time, which is why comparing them is useful. Here are the models you can overlay in Meteo·Models, and what each is good for.
Global vs regional models
Global models cover the whole planet and run out one to two weeks, so they trade resolution for reach. Regional models such as AROME (Météo-France, ~1.3 km) cover a limited area a couple of days out at much higher resolution, which lets them resolve thunderstorms, fog and terrain effects that global models smooth over. Meteo·Models focuses on the global models below, where multi-model comparison is most valuable.
The global models you can overlay
| Model | Run by | Coverage | Resolution | Updates (UTC) | Good for |
|---|---|---|---|---|---|
| ECMWF IFS | ECMWF (Europe) | Global | ~9 km (0.25° open data) | 00 / 12 UTC | The reference global model; most accurate in the medium range. |
| ECMWF AIFS | ECMWF (Europe) | Global | 0.25° | 00 / 12 UTC | ECMWF’s machine-learning model — fast, and competitive with the physics-based IFS. |
| GFS | NOAA / NCEP (USA) | Global | ~13 km (0.11° / 0.25°) | 00 / 06 / 12 / 18 UTC | Runs four times a day — the freshest global data; free and open. |
| NOAA AIGFS | NOAA (USA) | Global | 0.25° | 00 / 06 / 12 / 18 UTC | NOAA’s AI-based global forecast, run alongside the GFS. |
| ICON | DWD (Germany) | Global | ~13 km | 00 / 06 / 12 / 18 UTC | Icosahedral, non-hydrostatic grid; strong over complex terrain. |
| ARPEGE | Météo-France | Global (stretched) | ~5 km over Europe | 00 / 06 / 12 / 18 UTC | Higher resolution over Europe, coarser elsewhere. |
| UKMO Global | UK Met Office | Global | ~10 km | 00 / 12 UTC | The Unified Model; consistently among the top global performers. |
| GEM | CMC (Canada) | Global | ~15 km | 00 / 12 UTC | Environment Canada’s Global Environmental Multiscale model. |
| JMA GSM | JMA (Japan) | Global | ~13–20 km | 00 / 06 / 12 / 18 UTC | Japan’s Global Spectral Model; strong over the western Pacific. |
| CMA GRAPES | CMA (China) | Global | ~0.25° | 00 / 12 UTC | China Meteorological Administration’s global model. |
Because each model has different physics, resolution and data assimilation, they disagree — especially for precipitation and for anything beyond about five days. That disagreement is exactly what the certainty mask visualises. See how the consensus is computed on the methodology page. Read the methodology →