The characteristics of mesoscale convective system rainfall over Europe

Abstract

Mesoscale Convective Systems (MCS) are common over Europe and can produce severe weather, including extreme precipitation, which can lead to flash floods.The few studies analyzing the climatological characteristics of MCS over Europe are either based on only few years of data or focus on limited sub-areas.Using the recent Integrated Multi-satellitE Retrievals for Global Precipitation Measurement (IMERG) satellite precipitation climatology, we identify and track MCS for 16 years over Europe.We devise a spatial filter and track cells according to the overlap of filtered rain patches between consecutive time steps.By fitting an ellipse to these patches, we determine their overall shape and orientation.To distinguish convective rain patches we condition on lightning data, thus reducing potential identification errors.We analyze this new European MCS climatology to characterize MCS rainfall properties:MCS overall occur most frequently over the Mediterranean and Atlantic during fall and winter, whereas during summer, they concentrate over the continent.Typically, more than half of seasonal precipitation can be attributed to MCS, andtheir contribution to extreme precipitation is even greater, often exceeding 70\%.MCS over the continent display a clear diurnal cycle peaking during the afternoon, and some continental areas even show a second, nocturnal peak.The MCS diurnal cycle for coastal and oceanic regions is more variable.Selecting sub-areas, we find that the spatio-temporal distribution of MCS precipitation throughout the year can be well explained by the spatio-temporal distribution of specific environmental variables, namely (sea) surface temperature, fronts occurrence and convective instability.

Thunderstorm detection from GPM IMERG rainfall: Climatology of dynamical and thermodynamical processes over India

“…For example, Tyagi et al (2012) used cloud top temperature from very high‐resolution radiometer of Kalpana‐1 satellite at a spatial resolution of 8 km in 1‐h intervals to study the premonsoon thunderstorm occurrences in 2009. Previous studies have also used feature‐tracking algorithms to study mesoscale convective systems across the globe (e.g., Da Silva & Haerter, 2023; Feng et al, 2021; Huang et al, 2018). Huang et al (2018) used brightness temperatures and an area threshold of 5000 km 2 to classify the mesoscale convective systems.…”

“…They used a threshold area of 4 × 10 4 km 2 and a precipitation threshold of 2 mm·h −1 in the detection process. Da Silva and Haerter (2023) have used IMERG precipitation and lightning information from the European Cooperation for Lightning Detection network to detect and track mesoscale convective systems across Europe. However, all these studies have considered uniform threshold criteria for the detection of mesoscale convective systems across the study region, ignoring the spatial variability of rainfall associated with these systems.…”

“…This study is aimed to prepare a long‐term thunderstorm database for the premonsoon season in India using high‐resolution satellite rainfall, in addition to lighting data from FY‐4A geostationary data. In contrast to the Lagrangian approach followed by the previous studies (Da Silva & Haerter, 2023; Feng et al, 2021; Huang et al, 2018), this study attempts to detect premonsoon thunderstorms over India using a Eulerian approach. The derived thunderstorm database enables the study of spatial and temporal variations of thunderstorms.…”