We are pleased to announce the release of OpenIFS 48r1.  This version is based on IFS Cycle 48r1, which has been the ECMWF operational model since June 27th 2023 (see Model upgrade increases skill and unifies medium-range resolutions).

OpenIFS 48r1 is a significant scientific and technical upgrade from the previous OpenIFS 43r3v2 model release. This upgrade includes, for example, a moist physics upgrade, incorporation of multi-layer snow scheme, inclusion of operational CAMS chemistry and many more updates to the model physics parametrizations. Technical upgrades include a new build system (move from FCM to ecbuild/cmake), major restructure of the code, single and/or double precision builds as default, inclusion of the single column model (SCM) and ifs-test. For more details about the details of the release, specifically the differences between OpenIFS 43r3v2 and 48r1, please see the Release notes for OpenIFS 48r1.

As with previous OpenIFS releases, anyone wishing to use OpenIFS must have a OpenIFS license (see the list of Licensed Institutes).

Existing users of OpenIFS 43r3, who are at a licensed institute, should now have access to 48r1.  Please see the OpenIFS 48r1 User Guide for details about how to obtain OpenIFS 48r1, then build, test and run an experiment. If you are unable to access this user guide or the links within, please contact us at  openifs-support@ecmwf.int and we will investigate.

Finally, to run bespoke simulations with user requested initial data please follow details on OpenIFS Data Hub , which describes how to obtain initial data and simulation namelists from the OpenIFS datahub.

Please note!
OpenIFS 48r1 will not produce the same results as the previous releases based on 43r3v2.

Please report any queries or problems with this release to either the public OpenIFS User Forums (preferred) or privately to openifs-support@ecmwf.int.

All the best,

Adrian and Marcus
(OpenIFS team)