对流风暴内中气旋特征与强烈天气

The Characteristics of the Mesocyclone and Severe Weather Associated with Convective Storms

利用江苏盐城CINRADISA新一代天气雷达2005—2008年的资料分析盐城及周边地区对流风暴内中气旋和各种强对流天气的关系。对SA雷达中气旋探测算法识别的中气旋特征进行统计分析,发现带有中气旋的高顶高底的对流风暴易产生大冰雹;低底和带有较小直径的中气旋的对流风暴有利于龙卷的产生;后侧入流急流进入风暴有时会导致中气旋切变剧增、中气旋的底和顶降低而产生雷雨大风;低底和含有较低旋转速度的前侧中气旋容易导致短时暴雨。含有中气旋的对流风暴通常产生在对流有效位能较高和垂直风切变较大的环境条件下。

Based on 4-year observation data （2005--2008） acquired by Doppler weather radar located at Yancheng, the relationship between mesocyclones and the severe convective weather is analyzed. The re- sults show. （a） There is a high probability of large hail occurring on the right flank of the storms with high top and bottom of mesocyclones; （b） A storm with lower bottom and smaller diameter of mesocyclone is favorable for tornado; （c） Rear-inflow jet can intensify the wind shear of mesocyclone, make the mesocyclone descending, thus produce downdraft and strong wind; （d） The mesocyclones located on the front flank of storm with lower bottom and weaker wind shear usually cause heavy rain. Convective storm con- taining mesocyclone usually occurs in the environment with high CAPE and strong vertical wind shear.