The ECMWF IFS weather model

At a glance

What ECMWF IFS is

The IFS is the Integrated Forecasting System, the model at the heart of ECMWF. In everyday talk it is simply the Euro, and when a forecaster says the Euro and the GFS disagree about a storm, they mean the IFS and NOAA’s Global Forecast System.

For years, ECMWF ran a separate high-resolution forecast called HRES. With cycle 50r1, which became operational on May 12, 2026, ECMWF stopped running HRES and the ensemble control separately, because the previous cycle had already made them identical, so one control forecast remains. Older articles and charts still say HRES, and in current open data the deterministic forecast carries the label "oper". Cycle 50r1 also switched to fully coupled ocean and atmosphere forecasts, with a new ocean and sea-ice configuration, and changed the convection scheme.

The resolution of about 9 kilometers is finer than the GFS’s 13 kilometers, and the IFS is a physics-based model, in contrast to ECMWF’s machine-learning AIFS. ECMWF publishes an open data set of IFS and AIFS output on a 0.25 degree grid under a CC-BY-4.0 license, which is what 4070 shows.

Where it does well

• It is one of the two global models most forecasters check first, and a standard second opinion whenever the GFS shows something unusual.
• A finer grid than the GFS, so it can draw fronts and storm structure in more detail.
• It is a physics-based model with a long record, so forecasters know how it behaves.
• Open data for 4070’s views includes the fields forecasters check most: precipitation, temperature, wind, 850 and 500 mb, CAPE, cloud cover, precipitable water and precipitation type.

Where it falls short

• It runs the main forecast twice a day in 4070, at 00Z and 12Z, so it updates less often than the GFS.
• The open data set carries a subset of fields, at 0.25 degree. Some maps that exist for the GFS do not exist here.
• The deterministic forecast in open data runs 10 days, shorter than the GFS’s 16.
• A single IFS run is one run. Compare it with the previous run and with the ensemble.

What it is typically used for

• The large-scale pattern and storm tracks three to ten days out.
• A tiebreaker or comparison when the GFS looks unusual.
• Checking precipitation type and snowfall guidance, with the usual snow ratio caution.
• Comparing runs: has the Euro been steady or shifting from run to run?

How to see ECMWF IFS in 4070

The ECMWF model is in Model Explorer under Global Models, with 00Z and 12Z runs. It is part of 4070 Pro, which starts with a seven-day free trial.

• Fields include a classic precipitation, MSLP and temperature view, precipitation, 2 meter temperature, 10 meter wind, 850 hPa temperature, 500 mb heights and wind, 500 hPa vorticity, 250 hPa wind, dew point, wind gust, CAPE, cloud cover, precipitable water, precipitation type and snowfall guidance drawn by WDS.
• Regions include North America, the United States, Europe and the Northern and Southern Hemispheres.
• Compare Models puts the ECMWF beside the GFS or another compatible model at the same valid time. Each panel names its own run, so the runs can differ while the moment does not.
• Plumes include the three most recent ECMWF runs at a U.S. point.

How it fits with the other models

The GFS is the other global model forecasters check first. The IFS has a finer grid, the GFS runs more often and goes out 16 days. The ECMWF EPS is the ensemble built from the same system, and the AIFS is ECMWF’s machine-learning model. Read two or three together. Our guide to model accuracy explains why no one model leads in every season and every region.

Specifications change when agencies upgrade their models. The Sources below link to the producing agency. Official National Weather Service forecasts, watches and warnings remain the authority for what is expected where you live.