The structure of mesoscale convective systems in central Russia

Described is the organization of 216 summertime mesoscale convective systems (MCSs) in Moscow region. Initially, the horizontal radioecho fields corresponding to the stage of MCS reflectivity maximum were divided into 92 lines with the length of more than 200 km and 124 nonlinear MCSs. Subsequently, three types of lines were separated: lines with solid segments of reflectivity of more than 40 dBZ of ∼100 km long, discontinuous convection bands representing the combinations of linear and node-like amorphous thunderstorms, and convex or concave bow-shaped systems frequently forming the families of spirals or occlusions. The nonlinear MCSs contain circular radar cells (similar to open mesoscale cells) or small bow segments of ∼30 km; however, the most intensive storms have a propagation axis connecting the major MCSs. Finally, an objective classification of MCSs is proposed based on the quantiles of climatological distributions of various parameters describing the intensity, morphology, and kinematics of MCSs.