副高边缘两次大暴雨天气过程物理量特征分析

利用常规气象资料、NCEP 1°×1°再分析资料对2012年7月1~4日副高边缘四川省达州市连续两次大暴雨天气过程的物理量进行了重点分析。分析结果表明K指数和假相当位温垂直梯度变化与暴雨对应关系较好,850hPa比湿能很好的反映低层大气水汽含量情况,可以为暴雨预报的一个重要参考指标;副高边缘偏南气流提供了较好的水汽条件;垂直螺旋度与暴雨中心位置和强度有较好的对应关系;副高边缘西南气流使得垂直涡度增大,系统斜压性加强,有利于暴雨产生。 

The Physical Quantity Discussion of Two Rainstorm Weather on the Edge of Subtropical High

By using the routine meteorological data,NECP 1°×1° reanalysis data,we carries on the key analysis of the physical quantity of two coninues rainstorm weather process on the edge of subtropical high on July 1st to 4th,2012 in Dazhou.The results show that the storm have a good corresponding relationship with the K index and the change of potential pseudo-equivalent temperature vertical gradient,850hPa specific humidity can well reflect the lower atmospheric water vapor content,which can be an important reference index for the heavy rain.The edge of subtropical High southerly airflow provides good vapor conditions.The vertical helicity and rainstorm center has good corresponding relationship.The edge of subtropical high.The southwest airflow of the edge of subtropical high increase the vertical vorticity,and strengthen the system baroclinity,which is good to produce the rainstorm.