Forecast models
GRIB download times
GRIB files from global models typically start to appear between about three and eight hours after run time, and the full set of forecast hours takes longer. The table below shows each model.
A GRIB file is the compact format in which forecast centres publish model output and which sailing apps read: each record holds one weather parameter at one time on a grid. See GRIB files for what is inside and how big the files are.
Global models
| Model | Category | Run cycles (UTC) | First data after run time | Complete after run time |
|---|---|---|---|---|
| ICONDWD | Global | four times a day: 00Z, 06Z, 12Z and 18Z | 2 h 40 min | 3 h 28 min |
| ARPEGEMétéo-France | Global | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 3 h 10 min | ≈ 3 h 50 min |
| GFSNOAA / NCEP | Global | four times a day: 00Z, 06Z, 12Z and 18Z | 3 h 32 min | 5 h 14 min |
| GDPSECCC | Global | twice a day: 00Z and 12Z | 3 h 48 min | 5 h 08 min |
| CMA-GFSChina Meteorological Administration | Global | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 5 h 44 min | ≈ 5 h 44 min |
| ECMWF AIFSECMWF | AI / machine learning | four times a day: 00Z, 06Z, 12Z and 18Z | 5 h 45 min | 7 h 34 min |
| UKMO GlobalMet Office | Global | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 7 h 11 min | ≈ 7 h 11 min |
| ECMWF IFSECMWF | Global | four times a day: 00Z, 06Z, 12Z and 18Z | 7 h 34 min | 7 h 34 min |
| JMA GSMJMA | Global | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 9 h 31 min | ≈ 9 h 31 min |
Regional models
| Model | Category | Run cycles (UTC) | First data after run time | Complete after run time |
|---|---|---|---|---|
| ICON-D2DWD | Regional / high-res | eight times a day: 00Z, 03Z, 06Z, 09Z, 12Z, 15Z, 18Z and 21Z | 44 min | 1 h 21 min |
| HRRRNOAA / NCEP | Regional / high-res | Every hour | 50 min | 1 h 18 min |
| HARMONIE DINI (DMI)DMI | Regional / high-res | eight times a day: 00Z, 03Z, 06Z, 09Z, 12Z, 15Z, 18Z and 21Z | 1 h 34 min | 2 h 58 min |
| NAMNOAA / NCEP | Regional / high-res | four times a day: 00Z, 06Z, 12Z and 18Z | 1 h 38 min | 2 h 42 min |
| HARMONIE MEPS (Nordic)MET Norway, SMHI, FMI & partners | Regional / high-res | eight times a day: 00Z, 03Z, 06Z, 09Z, 12Z, 15Z, 18Z and 21Z | 1 h 40 min | 2 h 26 min |
| ICON-2IItaliaMeteo / Aeronautica Militare | Regional / high-res | twice a day: 00Z and 12Z | ≈ 2 h 02 min | ≈ 2 h 02 min |
| AROMEMétéo-France | Regional / high-res | 5 times a day: 00Z, 03Z, 06Z, 12Z and 18Z | ≈ 2 h 05 min | ≈ 2 h 45 min |
| HRDPSECCC | Regional / high-res | four times a day: 00Z, 06Z, 12Z and 18Z | 2 h 40 min | 3 h 21 min |
| ICON-EUDWD | Regional / high-res | eight times a day: 00Z, 03Z, 06Z, 09Z, 12Z, 15Z, 18Z and 21Z | 2 h 42 min | 2 h 50 min |
| JMA MSM / LFMJMA | Regional / high-res | eight times a day: 00Z, 03Z, 06Z, 09Z, 12Z, 15Z, 18Z and 21Z | ≈ 3 h 30 min | ≈ 3 h 30 min |
| ARPEGE EuropeMétéo-France | Regional / high-res | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 3 h 37 min | ≈ 3 h 37 min |
| RDPSECCC | Regional / high-res | four times a day: 00Z, 06Z, 12Z and 18Z | ≈ 3 h 57 min | ≈ 3 h 57 min |
Wave models
| Model | Category | Run cycles (UTC) | First data after run time | Complete after run time |
|---|---|---|---|---|
| GFS-WaveNOAA / NCEP | Waves | four times a day: 00Z, 06Z, 12Z and 18Z | 3 h 31 min | 5 h 11 min |
| DWD GWAM / EWAM / CWAMDWD | Waves | twice a day: 00Z and 12Z | ≈ 4 h 11 min | ≈ 4 h 11 min |
| ECMWF WAMECMWF | Waves | four times a day: 00Z, 06Z, 12Z and 18Z | 7 h 34 min | 7 h 34 min |
| MFWAMMétéo-France | Waves | twice a day: 00Z and 12Z | ≈ 12 h 04 min | ≈ 12 h 04 min |
Times are typical and can vary from run to run. Early forecast hours usually appear before the later ones. Figures marked ≈ are estimates.
How to avoid downloading an old run
Check the run time in the file or in your GRIB viewer before you rely on it: a download shortly after run time may still give the previous run. With a free account, Ilma can alert you when a run is published and give you a calendar feed of the expected run times. You can also see the next runs for every model on the timeline or in the model list. For waiting times in general, read When does a new run arrive?