A comparative study of observational and reanalysis data for extreme precipitation events in the Spanish Mediterranean

Extreme precipitation events in the coastal regions of the Spanish Mediterranean represent a significant meteorological risk due to their potential to cause flooding and other socio-economic impacts (Mateos et al., 2023). These extreme events are commonly associated with the autumn months, when atmospheric instability increases following the summer season, and Mediterranean Sea temperatures remain relatively high (Nieto-Ferreira, 2021). The interaction between the warm, moist air from the sea and the descending cold air aloft favours the formation of intense convective systems, leading to episodes of extreme rainfall (Mastrantonas et al., 2020). From a climatological perspective, the capacity of climate reanalysis data tends to underestimate extreme precipitation values. 

Therefore, the main motivation of this work is to perform a comparative study between the hourly observational data from AEMET and different high-resolution reanalyses: CERRA (Schimanke et al., 2021), CERRA-Land (Verrelle et al., 2022), EOBS (Cornes et al., 2018), ERA5-Land (Muñoz-Sabater et al., 2024) and ERA5 (Hersbach et al., 2023). This study focus on the Mediterranean basin regions of Spain, covering the period from 1995 to 2022 during the autumn months. 

The aim of this work is to assess the reliability of these reanalysis data in representing the most extreme precipitation events and to determine whether current reanalysis data can adequately capture the intensity, frequency, and spatial distribution of these events, which is crucial for improving predictions and management strategies for severe weather phenomena.