EUMETNET SRNWP-EPS EFI/SOT Software: From Research to Operations in AEMET-γSREPS

Abstract

The EUMETNET Short Range Numerical Weather Prediction - Ensemble Prediction System (SRNWP-EPS) EFI/SOT software is a result from the EUMETNET SRNWP-EPS 2019 to 2023 project. It computes the Extreme Forecast Index (EFI) and Shift of Tails index (SOT) for the different EUMETNET Member States Limited Area Modelling - Ensemble Prediction Systems (LAM-EPS). The software, implemented in Python 3, has been developed from scratch within a multiprocessor Linux environment: the European Centre for Medium-Range Weather Forecasts (ECMWF) ATOS High Performance Computer Facility (HPCF). The software has been developed testing on EFI and SOT indices for a wide variety of meteorological variables such as accumulated precipitation (AccPcp), accumulated snow (AccSnw), 2 m maximum and minimum temperature (T2mMax and T2mMin) and 10 m maximum wind gust (G10m). In order to overcome the computational limitations derived from LAM-EPSs in terms of constructing a large and robust EPS-climatology through an expensive re-forecast with the last LAM-EPS version, the software follows methods from Météo-France that consists of temporal and spatial relaxation techniques that include neighboring data in space and time to enrich the small available dataset used to construct the EPS-climatology. Additionally, the software introduces a land-sea mask that aims at applying physically-based restrictions to the grid points included by the spatial relaxation methods. Specific extreme weather events have been selected to showcase the software with some EUMETNET Member States LAM-EPSs. Moreover, an already operational implementation of the EUMETNET SRNWP-EPS EFI/SOT software is showcased in AEMET-γSREPS, the LAM-EPS developed and operationally run at AEMET, the Spanish Meteorological Agency. The software provides products similar to the ones from the European Centre for Medium-Range Weather Forecasts Ensemble (ECMWF ENS), and are currently available for AEMET forecasting offices.