2004—2009年大连地区短时暴雨分析预报

Analysis and forecast of short time heavy rain from 2004 to 2009 in Dalian region

为提高短时暴雨预警能力,利用2004—2009年3—10月大连降水资料和天气雷达回波资料,对此期间45次暴雨过程气候特征和活动规律等进行分析。结果表明:有32次过程出现短时暴雨,其中7—8月出现27次,占全部短时暴雨的84.4%。造成这些短时暴雨的雷达回波,主要是源于大连西南、南和东南部沿海的介于强对流性与稳定性之间的混合性降水回波,占70.0%或以上。将短时暴雨降水资料扩大到乡镇级自动站与雷达回波分析,结果发现:造成大连地区短时暴雨的直接原因是突发于混合性云团中的中-β尺度回波。通过归纳定义"混合性中-β尺度回波"模型,并结合其他探测信息和技术手段,可以提高短时暴雨预警能力。

Based on the precipitation data and radar echo data from March to October during 2004-2009,45 heavy rain events were analyzed in order to improve the warning ability to heavy rain.The results indicated that there are 32 short time heavy rain events.Among them,27 events occur in July and August that accounts for 84.4% of the whole.The mixed precipitation echoes between sever convection and stability along the coast of southwestern,southern and southeastern Dalian are the main reasons causing the short time heavy rain and account for more than 70%.A further study is conducted by using town-level precipitation data from automatic weather station（AWS） and radar echo data.It finds that the direct cause of short time heavy rain in Dalian is the instantaneously generated mixed meso-β echoes.Thus,the mixed meso-β echoes model is set up.This model could improve early warning ability of short time heavy rain with other methods.