The IFS is a global model that runs every twelve hours. Its output runs out to ten days in one-day intervals. The operational model runs both in a deterministic forecast mode and as a 51-member ensemble. The deterministic mode has twice the horizontal resolution of the ensemble, and one and a half times the vertical resolution (137 layers in the deterministic compared to 62 in the ensemble); both modes' vertical layers follow terrain at low levels. The IFS, like the GFS, uses spectral representation rather than a grid-based system.
Information from the IFS is proprietary and copyrighted, though the ECMWF has made a limited amount of the model's most important calculations available to the public; this public data is, by declaration of the ECMWF, in the public domain. In the United States, the IFS is generally used as a comparison against the American GFS model in the forecast period between four and ten days.