2011年7月2—3日山东大范围暴雨过程的诊断分析

为了进一步探讨山东短时暴雨发生发展的中尺度物理机制,分析强对流来临之前的中尺度信息,提高山东地区暴雨预报的准确率,利用常规观测资料,FY-2E卫星TBB资料和NCEP/NCAR 1°×1°的6 h再分析资料,对2011年7月2—3日山东大范围暴雨过程进行天气动力学诊断。结果表明,此次山东大范围暴雨是由高空冷涡、地面气旋、副热带高压等系统共同影响产生;副热带高压的稳定少动,低层切变线的出现,充沛而又深厚的水汽等条件的合理配置,造就了这次大范围暴雨;暴雨出现在850 hPa上MPV1正负值过渡带、MPV2弱负值区附近,是对流不稳定与斜压不稳定相结合的地区;研究中尺度对流云团范围和强度的不断变化对判断暴雨的发生发展有重要的指导作用。

Diagnosis Analysis of the Heavy Rain in Shandong Province, July 2-3, 2011

In order to further explore the mesoscale physical mechanism of short time rainstorm in Shandong, ande analyze the mesoscale information before strong convection comes, improve the accuracy of regional rainstorm forecast in Shandong. Using the conventional observed data, the FY-2E satellite TBB data and NCEP/NCAR 1 °×1° for 6 h reanaJysis data on 2011 July 2-3 Shandong rainstorm process had been diagnosed in synoptic and dynamic. The results showed that： the Shandong heavy rainstorm was caused by high altitude, cold ground cyclone and subtropical high pressure system; the maintaining subtropical high pressure, the appearance of the low level shear line in lower troposphere layer, the incursion of the cold air in middle and higher troposphere layer, strong instability energy as well as the abundant and deep water vapor and other weather conditions effective and reasonable, caused the heavy rainstorm; positive vertical helicity center had a good relationship with the change of the southwest vortex＇ s movement and intensity. Heavy rainstorm happened near the transition zone of MPV1 and weak negative zone on 850 hPa, and it combined the convective instability and baroclinic instability; there was an important guidance to research the MCC changing scope and intensity.