Investigation on potential and limitations of ERA5 Reanalysis downscaled on Italy by a convection-permitting model

Abstract This study presents a comprehensive assessment of dynamical downscaling ERA5 Reanalysis recently performed over Italy through the COSMO-CLM model at convection-permitting scale (0.02°) period 1989–2020. Results are analysed against several independent observational datasets and reanalysis products. The capability to realistically represent climatology for 2 m temperature precipitation is whole peninsula subdomains. Hourly patterns, orography effects, urban climate dynamics also investigated, highlighting weaknesses strengths model. In particular, gains in performances achieved mountainous areas where characteristics correctly represented, as hourly characteristics. Losses occur coastal flat Italian peninsula, performance does not seem be satisfactory, opposed complex orographic areas. adopted parameterisation demonstrated simulate heat detection two cities: Rome Milan. Finally, subset extreme indicators evaluated, finding: ( i ) region-dependent response, ii notable iii discrepancies South, Central Insular Climate detect events detailed scale, becoming an important tool turning data into information.