2013年初夏河南一次区域性暴雨天气过程的分析

利用常规资料和NCEP再分析资料,对2013年5月25—26日河南省区域性暴雨过程的环流形势、水汽条件和垂直螺旋度进行了分析,结果发现:西南涡沿切变线移出是暴雨形成的诱因,中低层低涡与涡前持续的低空急流为暴雨的产生提供有利的大尺度天气背景条件.700 hPa水汽通量变化对强降水落区有一定的指示作用,暴雨区一般位于水汽通量大值中心附近和前端等值线梯度密集带内;水汽通量辐合增强增厚降水增强.强降水多位于垂直螺旋度正大值中心附近和长轴两侧.

A Regional Rainstorm Weather Process in the Early Summer of 2013 in Henan

Using the conventio nal data and NCEP reanalysis data,we analyzed the circulation situation,water vapour condition,vertical helicity of a regional rainstorm process in Henan on 25-26,May 2013. The results showed that the southwest vortex moved along the shear line is the major cause of this rainstorm. The low vortex in the middle and low level and the low-level jet provided favorable conditions of large-scale weather background for the rainstorm formation. The change of vapor flux at 700 hPa has some indication at the heavy storm location. The storm area is near the maximal value of vapour flux and in the front of the isolines density gradient band. The heavy rain is located near the center of the positive high value of vertical helicity and two sides of the long axis.