2021年5月3日贵州省中东部一次强对流天气过程综合分析

Comprehensive Analysis of a Convective Weather in the Central and Eastern of Guizhou on May 3, 2021

摘要: 本文利用常规观测资料，ERA5再分析资料，欧洲中心预报资料等，分别从环流背景、大气环境物理量、动力场结构、可预报性等对2021年5月3日贵州省一次强对流天气过程进行综合分析。结果表明：① 此次天气过程是在高空冷槽的背景下，配合低层的切变线以及南风急流，在中尺度辐合线的触发下发生的强对流天气过程。② 高层冷平流配合低层暖脊以及地面热低压发展，使得贵州地区具有“上干冷，下暖湿”的不稳定层结。③ 对流发生前贵州中东部具有较强的不稳定能量、垂直风切变和适宜的0℃层高度。④ 冰雹发生区域有明显的正涡度柱以及低层辐合高层辐散，上升运动较强。⑤ 参考模式预报可以对此次对流的发生以及移向移速等进行较准确地预报，但可能会对部分地区的降水量级以及强对流天气的强度等预报存在误判。

Abstract: In this paper, a severe convective weather process in Guizhou Province on May 3, 2021 was comprehensively analyzed from the atmospheric circulation, environmental physical field values, dynamic structure and predictability of model, according to meteorological observation data, ERA5 reanalysis hourly data and ECMWF numerical forecasting products. The results show that: ① This weather process was a strong convective weather process triggered by the mesoscale convergence line under the background of upper-air cold trough, coupled with low-level shear line and southerly jet. ② With the development of high-level cold advection, low-level warm ridge and warm low on surface, Guizhou has an unstable stratification of the dry and cold in the high, warm and wet in the low. ③ Before convection, there were strong unstable energy, vertical wind shear and suitable 0˚C layer height in central and eastern Guizhou. ④ There were obvious positive vorticity columniations, structure of convergence-divergence from lower levels of troposphere to upper level in the hail occurrence area, with strong ascending motion. ⑤ According to ECMWF numerical forecasting products could accurately predict the occurrence, direction and velocity of the convection, but it might lead to misjudgment in intensity of precipitation and severe convective weather in some areas.