The ECMWF Public Datasets Service is being decommissioned and access to most datasets closed on 1 June 2023. In a final step later this year, access to the remaining multi-model datasets S2S and TIGGE will be migrated to a different system. For more information and possible alternatives, please consult the dedicated page on Decommissioning of ECMWF Public Datasets service.
In the Public Datasets web interface some items are not "checkable".
This means that it means that the data is not available. The availability of an attribute is changing dynamically when you change the selections of another attribute (eg "steps") due to the application dynamic features.