利用欧洲中期预报中心(ECMWF)ERA Interim全球再分析资料(0.75°×0.75°)对2013年6月7日发生在浙江省中北部的暴雨过程进行了相关诊断分析。结果表明:这次暴雨是在高空短波小槽东移加深,底层西南涡东移发展的形势下发生的,同时浙江中北部暴雨区位于高低空急流耦合带;暴雨发生前700 hPa以下蕴含有大量的不稳定能量,随着西南涡的靠近而触发不稳定能量释放;对大气变量物理分解的环境场分析发现此次区域性暴雨过程具有一定的背景环境支持,同时在瞬变扰动场的异常下而诱发了暴雨,暴雨落区位于850 hPa扰动暖切辐合线上。
The torrential rainfall in the middle and northern parts of Zhejiang Province on 7 June 2013 was diagnosed based on the latest ECMWF ERA-Interim global reanalysis data with 0.75°×0.75° resolution.The results show that the torrential rain was caused by two developing eastward-moving systems-an upper-level shortwave trough and a low-level southwest vortex,and the torrential rainfall area over the middle and northern of Zhejiang are located in the coupling area of the upper-level and low-level jet streams.A large amount of instability energy was stored below 700 hPa before the occurrence of rainstorm,which was triggered by the southwest vortex close to the torrential rainfall area.The analysis of environmental fields by means of physical decomposition of atmospheric variables shows that background ambient was in favor of this regional rainstorm,causing the instantaneous anomaly field to trigger the torrential rainfall at last.The torrential rainfall is obviously located in the anomalous warm convergence shear line at 850 hPa.