Monitoring atmospheric composition & climate
Near-real-time Production

The prototype once-daily system run in the preparatory GEMS project will be evolved in MACC so it produces global analyses and forecasts twice-daily within a few hours of observation time. The cut-off times for observational data receipt and the production schedule in general will be chosen to optimise real-time product quality for users, taking into account the reliability with which schedules can be maintained. A conservative schedule is adopted initially, and the schedule will be refined in the light of user requirements, the demands for timely boundary conditions for MACC’s regional forecast production and the practical constraints of the latency in observational data receipt and of available computing capacity.

The system will be updated periodically. Updates will be tied as far as practically possible to updates of ECMWF’s operational weather forecasting system, to ensure that both meteorological and technical components of the MACC production system remain up-to-date. The changes introduced with each new version of the ECMWF system are summarised at

This will in future include the changes originating from MACC as well as from ECMWF’s core weather forecasting developments. Any additional changes that are not associated with a formal change in version of the forecasting system, such as initiation or cessation of use of a particular stream of observational data, or bug-fixes affecting product quality, will be logged on the Near-real-time Updates page.

Trial product datasets from any parallel runs carried out in preparation for an upgrade of the production system will be made available to the extent that is practical and appropriate, following the practice adopted for ECMWF’s operational weather-forecasting production streams.