High resolution regional re-analysis ensemble for Austria

In recent decades reanalysis products have emerged as a pivotal resource for numerical model evaluations, significantly enhancing our understanding of Earth’s system. They have also been employed in various projects aimed at climate monitoring and assessment of climate change impacts. In this study, we present first results from ongoing work aimed at creating a first of its kind high resolution reanalysis ensemble for Austria. ECMWF's ERA5 ensemble is downscale to a 2.5 km resolution by employing three-dimensional variational assimilation (3DVAR) system available in AROME. Upon completion, this dataset will provide spatially, temporally, and physically consistent 3D and 2D atmospheric fields spanning from 2012 to 2022. The presented analysis focused on representation of three distinct extreme precipitation events simulated in a one and a half year long simulation (01-01-2021 to 30-06-2022). The reanalysis ensemble is compared with operational weather models and a high resolution (1 km x 1 km) gridded observational reanalysis. Based on statistical scores, all variations are ranked. In general, the results are on par with our operational models, however, some ensemble members exhibit slightly better performance compared to our operational models, which highlights the advantages of employing an ensemble system.