2013年雷州半岛一次罕见冬季暴雨过程的分析

Analysis of a Rare Winter Rainstorm over Leizhou Peninsula in 2013

基于常规观测资料、卫星云图、多普勒雷达以及数值预报资料,分析了2013年12月14—16日雷州半岛冬季暴雨个例的环流背景和物理量场特征。结果表明:500 h Pa南支槽和副热带高压长期存在于雷州半岛两侧,低层低涡及暖式切变线稳定,为暴雨发生提供有利的环境条件;西南暖湿气流与高空槽引导的冷空气汇集,为暴雨区输送水汽和能量,暴雨初期水汽通量>15 g·cm-1·h Pa-1·s-1;暖平流与正涡度平流共同作用,加强了暴雨的发展。

Using the conventional observation data, satellite cloud imagery, the detection data of a Doppler radar and numerical forecast products, we discussed the circulation background along with the phys- ical characteristics of the rainstorm that occurred over Leizhou Peninsula during 14 -16 December, 2013. A southern through in the westerlies and the subtropical high on both sides of the Leizhou Peninsula maintained steadily at 500 hPa, and a vortex and a warm shear line existed in the lower atmosphere. These configura- tions became a good circulation system helpful for the occurrence of the heavy rain. Southwest warm moist air met with dry cold air brought by the upper troughs, which provided sufficient vapor and energy. At the be- ginning of the heavy rain, a moisture flux at 850 hPa reached 〉15 g·cm-1·h Pa-1·s-1 Warm advection, combined with positive vorticity advection, was favorable for the emergence and development of the rainstorm in this region.