Strength and Challenges of global model MPAS with regional mesh refinement for mid-latitude storm forecasting: a case study

Abstract. With the rising share of renewable energy sources like wind in mix, high-impact weather events mid-latitude storms increasingly affect production, grid stability and safety reliable forecasting becomes very relevant for e.g. transmission system operators to allow actions reduce imbalances. Traditionally, meteorological forecasts are provided by limited-area prediction models (LAMs), which can use high enough model resolution represent range atmospheric scales motions associated with such storm structures. While generally satisfactory, deterioration insufficient deepening large-scale structures observed when they introduced near lateral boundaries LAM due inadequate spatial temporal interpolation. Global regional mesh refinement capabilities Model Prediction Across Scales (MPAS) have potential provide an alternative, while avoiding sharp jumps boundaries. In this study, MPAS' simulating key evaluation metrics intensity, location duration investigated based on a case study assessed comparison buoy measurements, forecast products from Climate Forecast System (CFSv2) simulations Weather Research Forecasting (WRF) LAM. Quasi-uniform variable-resolution MPAS configurations different physics settings designed analyze impact performance. shows good performance predicting intensity local minimum sea level pressure, time pressure (storm duration) was estimated too late (too long) measurements part early west-wards shift center MPAS. The showed combination additional south-westwards deviations field south-west that bias at some locations. highlights need more detailed analysis applied refinements particular applications emphasizes importance methods data assimilation techniques prevent drifts.