Global High-Resolution Models Vs. Limited-Area Models: Verification Of Hres-Ifs And Wrf-Arw Forecasts Over Catalonia

Over recent decades, numerical weather prediction (NWP) has undergone big improvements thanks, in part, to the increase in the computational power available to run forecast models. This has led global weather models to currently run with grid-cell sizes similar to those used in most of the traditionally used limited-area models (LAMs). One example of this is the ECMWF high-resolution deterministic model, the HRES-IFS, which currently runs operationally with a horizontal grid resolution of 9 km. Under these premises, some questions can be raised: does it make sense to continue running LAMs for operational weather forecasting? Is it enough to use the output of a global model at 9 km for regional or even local forecasts? In this preliminary study, the outputs of some simulations performed with the WRF model over Catalonia for January and July 2018 are compared with the HRES-IFS operational forecast for the same dates.