三门峡“07．13”短时强降水形成机制及预报难点分析

利用单站气象要素逐小时资料、NCEP 1°×1°再分析资料以及MICAPS常规资料,从过程实况、大尺度环流背景、物理量等方面,对2012年7月13日20:00~14日00:00发生在三门峡市区及附近的短时局地强降水过程的形成机制及预报难点进行了详细分析。结果表明,这次短时强降水是在有利的大尺度环流背景下产生的,整个过程冷空气活动均非常活跃;三门峡站气象要素演变对降水开始具有较好的指示意义;过程的水汽条件及动力条件在降水开始前6 h左右仍然不利于产生降水,直到降水开始前2 h左右才逐渐转化为有利条件。过程预报中存在气象参考资料时空分辨率不足以及水汽条件与当地暴雨预报指标不一致两大难点,业务中需要在不断完善当地暴雨预报指标的基础上,着重从短时临近角度进行分析预报。

Analysis on Formation Mechanism and Forecast Difficulty of the Short-time Strong Rainfall Occurred in Sanmenxia on 13 July

Based on the single station meteorological hourly data, NCEP 1°×1°reanalysis data and MICAPS data, from aspects of process, large scale circulation backgroud, physical quantity, the formation mechanism and forecasting difficulties of the short-time strong precipitation process was analyzed in detail, which occurred in Sanmenxia City and the nearby local from 20:00 13 July to 00:00 14 July, 2012.The results showed that the short-time strong rainfall generated in the favorable large scale circulation background, the cold air activities during the whole process were very active;the Sanmenxia meteorological elements evolution had a good indication to precipitation;water vapor conditions and dy-namic conditions won’t still conducive to produce precipitation on 6 hours before precipitation in the precipitation process, until 2 hours before the rainfall it gradually gradually transformed into favorable conditions.Two difficulties of forecasting were low time and space resolution of the meteorological reference information and diffence of water vapor conditions and local rainstorm forecast indicators,analysis and forecast were con-ducted mainly from the angle of nowcasting, based on continuous improvement of the local rainstorm forecast index.