ECMWF Model Upgrade Improves Extended-Range Weather Forecasts

- A wide-ranging upgrade of ECMWF's Integrated Forecasting System (IFS), implemented on 5 June 2018, brings better global weather forecasts, with particularly consistent gains in the extended range. A key plank of the upgrade is enhanced dynamic coupling between the ocean, sea ice and the atmosphere. The upgrade:      (Logo: https://mma.prnewswire.com/media/701698/ECMWF.jpg ) Up to now, dynamic ocean, sea ice and atmosphere coupling has only been applied in medium-range ensemble forecasts (18 km horizontal resolution), extended-range forecasts and seasonal forecasts. The upgrade extends this coupling to ECMWF's medium-range high-resolution forecasts (9 km horizontal resolution). In addition, the upgrade enhances coupling in the tropics for both high-resolution and ensemble forecasts. As a result, the IFS is now more consistent and seamless across different timescales and spatial resolutions. Other changes include: The changes are based on research by scientists at the Centre, often in collaboration with other scientists in ECMWF's Member States and beyond. Accounting for the drift of radiosondes has notably been made possible by a new data format providing full position information that is being rolled out across the world. Director of Forecasts Florian Pappenberger said: "The new model version brings pronounced improvements in upper-air predictions in the tropics, especially for wind and temperature. It is exciting to see the consistent gains in extended-range forecasts and the overall improvement in 2-metre temperature both in high-resolution and ensemble forecasts, particularly for Europe. In addition, near-coastal precipitation in warm-rain dominated situations is significantly improved, addressing a long-standing issue with our model." Director of Research Andy Brown said: "This is a substantial upgrade which marks a milestone towards our Strategy to 2025. The Strategy calls for a more seamless forecasting system by making our different forecasts more coherent. The enhanced coupling across all time ranges brings us one step closer to seamlessness. In addition to the important immediate benefits the upgrade delivers, it prepares the ground for further sustained progress." Notes for editors  The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by 34 states, established in 1975. ECMWF's core mission is to produce numerical weather forecasts, carry out scientific and technical research to improve forecast skill, and to maintain an archive of meteorological data. For more details, please see: https://www.ecmwf.int/en/about/media-centre/news/2018/ifs-upgrade-improves-extended-range-weather-forecasts    For more information, please contact: ECMWF Press Office, +44-118-949-9000, [email protected]