2006-06-13贵州省望谟县大暴雨的诊断分析

Diagnostic Analysis of 2006-06-13 Torrential Rain in Wangmo,Guizhou

利用NCEP/NCAR再分析资料、观测资料、FY-2C的红外云图TBB资料以及多普勒雷达的实时监测资料,对2006年6月13日发生在贵州省望谟县的突发大暴雨天气进行了研究,综合分析了此次强降水天气过程的影响系统、中尺度对流云团的发生发展演变、雷达回波特征及物理量场特征。结果表明,望谟县的短时强降水是受河套冷空气快速南下影响而致使贵州中部的辐合线南压锋生诱发β中尺度云团的生成与强烈发展所引起的。强降水区域与低层辐合带直接相关;对流层低层有能量锋出现,锋前积聚较强的潜在湿有效位能,在斜压扰动下,激发了倾斜垂直涡度的发展,导致大气层结对流性不稳定强烈发展,使中尺度对流系统得以发展和维持;雷达回波图反映了典型的中尺度系统特征。

Based on the routine observational data as well as automatic weather stations data, FY-2C satellite cloud pictures, the NCEP/NCAR reanalysis data and Doppler radar data in Guizhou, a torrential rain on June 13,2006 in Wangmo, Guizhou Province is analyzed. The direct impact system of the torrential rain, the evolution of mesoscale convective cloud clusters, the characteristics of Doppler radar echoes and physical characters are researched. The diagnostic results show that the heavy rain in a short time in Wangmo was caused by the vigorous development of meso-β cloud clusters, induced by the frontogenesis on a convergence line in the southwest of Guizhou under the impact of the rapidly southward moving of the cold air from Hetao. The region of heavy rainfall was directly linked to the convergence zone, where an energy front existed in low levels. Moist available potential energy was accumulated ahead of the front. The baroclinic disturbance induced the development of vorticity, leading to the intensive development of convective unstability. Radar echoes revealed typical mesco-scale characteristics of the torrential rain.