High-Resolution Spatiotemporal Distribution Characteristics and Environmental Conditions of Severe Convective Wind Events in China from 2016 to 2022

Abstract

The high-resolution spatiotemporal distributions and environmental conditions of severe convective wind (SCW) events in China from 2016 to 2022 are examined. SCW events predominantly occur from April to September, with a June peak over North China–Northeast China (NC–NEC) and a relatively uniform distribution from May to August over South of the Yangtze River (SYR). SCW frequency increases markedly by 1200 BJT, with the majority occurring during the afternoon to early evening. A comprehensive analysis of key thermodynamic and kinematic parameters reveals pronounced seasonal and regional contrasts in SCW environments. In spring, SCW activity concentrates over SYR, where favorable synoptic forcing coincides with abundant low-level moisture, large surface-based convective available potential energy (SBCAPE), and pronounced vertical wind shear. By contrast, springtime events over NC–NEC occur in a deep, dry mixed boundary layer environment characterized by lower SBCAPE but steeper 0–3 km and 850–500 hPa lapse rates (LR03, LR85). In summer, synoptic forcing weakens, yet SCW activity peaks over NC–NEC, where sufficient buoyancy, relatively strong shear, and moderate LR85 support organized convection. Conversely, summer events over SYR develop beneath or along the periphery of the western Pacific subtropical high in a high-SBCAPE, weak-shear environment, indicating that buoyancy-related thermodynamic support is more prominent than wind shear support. Enhanced vertical wind shear, especially deep-layer shear, emerges as the primary discriminator between significant and ordinary SCW events in spring and over NC–NEC in summer. These results demonstrate that the environmental support for SCW events varies substantially by season and region, highlighting the need for regionally informed severe convective wind prediction.