The German Climate Forecast System: GCFS

• Published in: Journal of Advances in Modeling Earth Systems
• Main Authors: Kristina Fröhlich, Mikhail Dobrynin, Katharina Isensee, Claudia Gessner, Andreas Paxian, Holger Pohlmann, Helmuth Haak, Sebastian Brune, Barbara Früh, Johanna Baehr
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2021
• Subjects: development; Earth‐system; forecasts; model; seasonal; Physical geography; GB3-5030; Oceanography; GC1-1581; North Atlantic; North Atlantic oscillation
• Online Access: https://doi.org/10.1029/2020MS002101; https://doaj.org/article/88b3f03ac644498faa312fb44b561204

Abstract Seasonal prediction is one important element in a seamless prediction chain between weather forecasts and climate projections. After several years of development in collaboration with Universität Hamburg and Max Planck Institute for Meteorology, the Deutscher Wetterdienst performs operational seasonal forecasts since 2016 with the German Climate Forecast System, now in Version 2 (GCFS2.0). Here, the configuration of the previous system GCFS1.0 and the current GCFS2.0 are described and the performance of the two systems is compared over the common hindcast period of 1990–2014. In GCFS2.0, the forecast skill is improved compared to GCFS1.0 during boreal winter, especially for the Northern Hemisphere where the Pearson correlation has increased for the North Atlantic Oscillation index. Overall, a similar performance of GCFS2.0 in comparison to GCFS1.0 is assessed during the boreal summer. Future developments for climate forecasts need a stronger focus on the performance of interannual variability in a model system.