Warm Rain Analysis from Remote Sensing Data in the Metropolitan Area of Barcelona for 2015–2022

Abstract

The Metropolitan Area of Barcelona is one of the most densely populated European regions. The hydrological conditions are very extreme, as are those of the Mediterranean Basin, with long drought periods. The management of water systems is one of the priorities, implying the understanding of the whole life cycle of water. One of the worst-known steps in this cycle corresponds to the rainfall events occurring between warm and cold periods, with quasi-tropical precipitation but with little or no lightning activity. This manuscript relies on the analysis of this type of precipitation for 2015–2022 for characterization and modelling to provide the signatures that can help diagnose these events in real time. The comparison of cold convective and warm rain events thorough radar, lightning and numerical weather prediction data has allowed us to find the main differences between both types. Warm rain events are predominant in the region, with more than 70% cases exceeding 10 mm of daily precipitation. The maritime influence is crucial in most of the warm rain episodes.