IFS upgrade brings many improvements and unifies medium-range resolutions
La mise à jour de l'IFS apporte de nombreuses améliorations et unifie les résolutions de moyenne échéance
Lang, Simon ; Schepers, Dinand ; Rodwell, Mark
An upgrade of ECMWF's Integrated Forecasting System (IFS) was implemented on 27 June 2023. One highlight is a horizontal resolution increase of the medium-range ensemble (ENS) to TCo1279 (9 km), which brings it to the same resolution as the high-resolution forecast (HRES). In addition to upper-air score improvements, the new ENS especially improves the skill of surface variables, such as 2 m temperature and 10 m winds, and tropical cyclones. The number of ensemble members for the extended-range ensemble forecast has increased from 51 to 101 members, and it is now run daily instead of twice weekly. These configuration changes result in substantial improvements in skill and utility for users. IFS Cycle 48r1 also benefits from a multitude of improvements to the data assimilation system as well as the forecast model, including for example higher inner-loop resolution in the data assimilation system, the assimilation of surface-sensitive microwave imager channels over land and cold ocean surfaces, and a multi-layer snow scheme in the forecast model.</p>
Accès à la notice sur le site du portail documentaire de Météo-France