2013年3月20日湖南和广东雷暴大风过程的特征分析
|
摘要
利用常规探空资料、多普勒天气雷达资料和风廓线雷达资料对2013年3月19日夜里到20日凌晨发生在湖南中南部和广东北部的一次区域性雷暴大风天气进行了分析,发现本次强对流天气过程的天气尺度背景是北支高压脊的崩溃和南支槽的建立,槽前出现较强的低空急流和切变线并在湖南中南部和广东北部形成了上干冷下暖湿的温湿配置结构下发生并强烈发展的;地面自动站观测显示北风侵入到前期露点温度较高的贵州黄平地区并形成风向辐合触发了对流,之后对流单体东移进入前期地面辐合线和露点锋相配合,同时500 hPa极为干冷的湖南中部偏南地区不断发展加强成对流带;雷达观测显示19日夜里在湖南西部不断出现对流单体并在其东移南下过程中最终形成飑线结构,该飑线中存在多个超级单体;通过多普勒天气雷达的中气旋产品与雷暴大风出现时间对应比较发现:大多数由中气旋引发的雷暴大风,在雷暴大风出现前2~3个体扫,其中气旋底高不断下降至2 km左右或以下,且在雷暴大风出现前1~2个体扫,中气旋的最强切变高度显著下降至中气旋底高位置附近;通过风廓线雷达数据与雷暴大风出现时间对应比较发现:底层大气折射率结构常数(C_n~2)大幅度的跃升通常在雷暴大风出现前10~15 min左右出现,其对雷暴大风的出现可能具有一定的指示意义。
Based on the conventional sounding observation data,Doppler radar data and wind-profiling radar data,a thunderstorm gale process that occurred in Hunan and Guangdong from the night of 19 to the morning of 20 March 2013 is analyzed.The results show that the background of this strong convective weather process is the collapse of the northern branch ridge and the establishment of the southern branch trough.Strong low-level jet and the shear line appear before the trough,which causes the dry and cold air above the level of the warm and humid air and makes the convection develop strongly.The automatic observation shows that the convective cell is triggered when the north wind enters into Huangping Guizhou(where the dew point temperature is higher than the surrounding areas) and forms wind convergence.After that,the convective cells moves into the south region of Hunan where there is a convergence line matching a dew point front and strengthens to a severe convective zone while it is extremely cold and dry at500 hPa.Over the night of the 19 th many convective cells emerge in the western Hunan,forming a squal line at last.There are many supercells in the squal line.By comparing the mesocyclone product of the radar with the time of the thunderstorm gale,it is found that the bottom of the mesocyclones continues droping to below 2 km about 2-3 volume scans before the appearance of the most thunderstorm winds resulting from the mesocyclone,and the strongest shear height drops to the bottom height of mesocyclone about1-2 volume scans before the appearance of the thunderstorm gale.In addition,after comparing the wind profiler radar data with the time of thunderstorm gale,we also get conclusion that a substantial jump of the bottom refraction index structure constant(C_n~2)always appears about 10-15 min before the time of thunderstorm wind,which is probably indicative to the appearance of wind.
Based on the conventional sounding observation data,Doppler radar data and wind-profiling radar data,a thunderstorm gale process that occurred in Hunan and Guangdong from the night of 19 to the morning of 20 March 2013 is analyzed.The results show that the background of this strong convective weather process is the collapse of the northern branch ridge and the establishment of the southern branch trough.Strong low-level jet and the shear line appear before the trough,which causes the dry and cold air above the level of the warm and humid air and makes the convection develop strongly.The automatic observation shows that the convective cell is triggered when the north wind enters into Huangping Guizhou(where the dew point temperature is higher than the surrounding areas) and forms wind convergence.After that,the convective cells moves into the south region of Hunan where there is a convergence line matching a dew point front and strengthens to a severe convective zone while it is extremely cold and dry at500 hPa.Over the night of the 19 th many convective cells emerge in the western Hunan,forming a squal line at last.There are many supercells in the squal line.By comparing the mesocyclone product of the radar with the time of the thunderstorm gale,it is found that the bottom of the mesocyclones continues droping to below 2 km about 2-3 volume scans before the appearance of the most thunderstorm winds resulting from the mesocyclone,and the strongest shear height drops to the bottom height of mesocyclone about1-2 volume scans before the appearance of the thunderstorm gale.In addition,after comparing the wind profiler radar data with the time of thunderstorm gale,we also get conclusion that a substantial jump of the bottom refraction index structure constant(C_n~2)always appears about 10-15 min before the time of thunderstorm wind,which is probably indicative to the appearance of wind.
引文
戴建华,陶岚,丁扬,等.2012.一次罕见飑前强降雹超级单体风暴特征分析.气象学报,70(4):609-627.
何平.2006.相控阵风廓线雷达.北京:气象出版社,43-45,49.
罗建英,廖胜石,梁岱云,等.2006.2005年3月22日华南飑线的综合分析.气象,32(10):70-75.
马中元,苏俐敏,谌芸,等.2014.一次强飑线及飑前中小尺度系统特征分析.气象,40(8):916-929.
潘玉洁,赵坤,潘益农,等.2012.用双多普勒雷达分析华南一次飑线系统的中尺度结构特征.气象学报,70(4):736-751.
邵玲玲,黄宁立,邬锐。等.2006.一次强飑线天气过程分析和龙卷强度级别判定.气象科学,26(6):627-632.
王秀明,俞小鼎,周小刚,等.2012.“6.3”区域致灾雷暴大风形成及维持原因分析.高原气象,31(2):504-514.
吴芳芳,俞小鼎,张志刚,等.2012.对流风暴内中气旋特征与强烈天气.气象,38(11):1330-1338.
伍志方,庞古乾,贺汉青,等.2014.2012年4月广东左移和飑线内超级单体的环境条件和结构对比分析.气象,40(6):655-667.
姚建群,戴建华,姚祖庆.2005.一次强飑线的成因及维持和加强机制分析.应用气象学报,16(6):746-754.
姚叶青,俞小鼎,张义军,等.2008.一次典型飑线过程多普勒天气雷达资料分析.高原气象,27(2):373-381.
于庚康,吴海英,曾明剑,等.2013.江苏地区两次强飑线天气过程的特征分析.大气科学学报,36(1):47-59.
俞小鼎.2012.强对流天气临近预报.北京:中国气象局气象干部培训学院,5-6.
俞小鼎,姚秀萍,熊廷南,等.2006.多普勒天气雷达原理与业务应用.北京:气象出版社,122-123,169.
Johns R H,Doswell C A III.1992.Severe local storms forecasting.Wea Forecasting,7:588-612.
何平.2006.相控阵风廓线雷达.北京:气象出版社,43-45,49.
罗建英,廖胜石,梁岱云,等.2006.2005年3月22日华南飑线的综合分析.气象,32(10):70-75.
马中元,苏俐敏,谌芸,等.2014.一次强飑线及飑前中小尺度系统特征分析.气象,40(8):916-929.
潘玉洁,赵坤,潘益农,等.2012.用双多普勒雷达分析华南一次飑线系统的中尺度结构特征.气象学报,70(4):736-751.
邵玲玲,黄宁立,邬锐。等.2006.一次强飑线天气过程分析和龙卷强度级别判定.气象科学,26(6):627-632.
王秀明,俞小鼎,周小刚,等.2012.“6.3”区域致灾雷暴大风形成及维持原因分析.高原气象,31(2):504-514.
吴芳芳,俞小鼎,张志刚,等.2012.对流风暴内中气旋特征与强烈天气.气象,38(11):1330-1338.
伍志方,庞古乾,贺汉青,等.2014.2012年4月广东左移和飑线内超级单体的环境条件和结构对比分析.气象,40(6):655-667.
姚建群,戴建华,姚祖庆.2005.一次强飑线的成因及维持和加强机制分析.应用气象学报,16(6):746-754.
姚叶青,俞小鼎,张义军,等.2008.一次典型飑线过程多普勒天气雷达资料分析.高原气象,27(2):373-381.
于庚康,吴海英,曾明剑,等.2013.江苏地区两次强飑线天气过程的特征分析.大气科学学报,36(1):47-59.
俞小鼎.2012.强对流天气临近预报.北京:中国气象局气象干部培训学院,5-6.
俞小鼎,姚秀萍,熊廷南,等.2006.多普勒天气雷达原理与业务应用.北京:气象出版社,122-123,169.
Johns R H,Doswell C A III.1992.Severe local storms forecasting.Wea Forecasting,7:588-612.
目录