贵州铜仁3.30大范围降雹天气过程分析

Analysis of the Widespread Hail Weather Event in Tongren, Guizhou on March 30

摘要: 本次过程利用常规气象观测、铜仁市多普勒雷达、探空观测和NCEP再分析资料，研究分析了2021年3月30日下午发生在贵州省铜仁市多个县的一次大范围冰雹强对流天气过程，探寻铜仁市冰雹强对流天气的预报指标，借此提高对此类灾害性天气的监测和预警能力。结果表明：1) 本次强对流天气属于典型的贵州热低压辐合线型，主要影响系统为500 hPa高空槽，700 hPa、850 hPa切变线，低空急流和地面热低压；2) 大气垂直上升运动强，地面辐合线的触发，水汽输送集中在低层，低层强水汽辐合使降雹区的中低层水汽条件充沛，有利于强对流的产生；3) 探空资料的对流有效位能(CAPE)、K指数、沙氏指数(SI)等指示意义较好，不稳定能量的聚集，适宜的0℃层、−20℃层高度与较强垂直风切变对冰雹的形成有利；4) 降雹区垂直累积液态水含量(VIL)集中在40~55 kg∙m⁻²之间，50 dBz以上的强回波顶高在8 km以上，降雹区最小VIL为27.4 m∙s⁻¹。

Abstract: Utilizing conventional meteorological observations, Doppler radar, radiosonde observations, and NCEP reanalysis data, a comprehensive analysis was conducted of a widespread hailstorm and severe convective weather event that occurred in multiple counties of Tongren City, Guizhou Province on the afternoon of March 30, 2021. The study sought to identify predictive indicators for severe convective weather involving hail in Tongren City, aiming to enhance the monitoring and early warning capabilities for such disastrous weather events. The results indicate: 1) This severe convective weather event was characteristic of a typical Guizhou hot low pressure convergence line type, primarily influenced by a 500 hPa upper-level trough, shear lines at 700 hPa and 850 hPa, a low-level jet and surface thermal low pressure; 2) There was strong vertical atmospheric ascent, with triggering by surface convergence lines, and moisture transport concentrated in the lower atmosphere. Strong low-level moisture convergence in the hailfall area created abundant moisture conditions in the mid and lower levels, conducive to the generation of severe convection; 3) Radiosonde data indicators such as Convective Available Potential Energy (CAPE), K-index, and Showalter Index (SI) were found to be significant, and the accumulation of unstable energy, suitable 0˚C level and −20˚C level heights, together with strong vertical wind shear, were favorable for hail formation; 4) In the hailfall areas, the vertical integrated liquid (VIL) was concentrated between 40~55 kg∙m⁻², with the strong echo top height of echoes above 50 dBz being over 8 km, and the lowest VIL recorded was 27.4 m∙s⁻¹.