河北省中南部一次MCC造成的暴雨过程分析

Analysis of a Rainstorm Process Caused by MCC in Mid-south of Hebei Province

应用GMS红外辐射亮温(TBB)资料、NCEP 1°×1°再分析资料及探空和自动站等资料,对2008年6月27日傍晚到夜间影响河北省中南部的一次MCC(中尺度对流复合体)天气过程进行了诊断分析。结果表明:MCC形成到成熟阶段在其西侧TBB梯度最大的地方均造成了雷暴、强降水、大风等强对流天气。高空低涡、高空槽和地面切变线是此次MCC的主要影响系统,对流层中低层高温高湿的环境为MCC的生成和发展提供了有力的热力条件,低空急流为暴雨的产生供应了充沛的水汽。850 hPa上湿正压位涡项负值区(MPV1<0)与湿斜压位涡项正值区(MPV2>0)的叠加很好地指示了暴雨的落区。

Based on the GMS Infrared radiation TBB,NCEP 1°x 1° reanalysis data,T-lnP and rainfall data of surface automatic stations,a MCC weather process occurred in mid-south of Hebei province on June 27,2008 was diagnosed.Results showed that from the forming stage to the mature period of the MCC,severe convective weather such as thunderstorms,heavy precipitation,gales appeared in west of the MCC where the TBB grads was biggest.The main weather systems caused the MCC were upper vortex,the trough in the upper layer and the ground wind shear.The environmental conditions of high temperature and humidity in the lower troposphere provided a favorable thermodynamic condition for the forming and developing of MCC.The low level jet of 850 hPa provided abandant vapor for the heavy rain,which occurred in the overlapping zone of negative MPV1 and positive MPV2.