Example of extra observations assimilated in a single data assimilation cycle as a result of changes in ECMWF’s Integrated Forecasting System planned for June.
ECMWF upgrades its forecasting system on a regular basis, and one such upgrade is currently planned for June 2019. These upgrades enable the Centre to integrate the latest scientific advances into its Integrated Forecasting System (IFS).
Ahead of the implementation of IFS Cycle 46r1 planned for June, Director of Research Andy Brown will explain the changes and how they will improve forecasts in a webinar on 26 February and again on 7 March.
The upgrade brings major improvements in data assimilation – the combination of Earth system observations with model information to define the initial conditions for forecasts – as well as in modelling and the range of observations used.
Together the changes result in substantially better forecasts across the range of predicted values, including near-surface weather variables such as wind and temperature.
Highlights include the introduction of continuous data assimilation, which enables the use of more observations, and of a 50-member Ensemble of Data Assimilations (EDA). The increase in EDA members from 25 to 50 improves both ECMWF’s high-resolution initial conditions and the perturbations to the initial conditions for the 50-member ensemble forecast.
Join the webinars
Both webinars have now taken place and a recording is available. The presentation slides are also available separately: 
46r1_overview_AndyBrown.pdf.
A list of what is different in IFS Cycle 46r1 is provided on the implementation page for forecast users, where regular updates on this upgrade will be posted over the next few months.