云南冰雹灾害的多普勒雷达特征统计及预警指标

Doppler Radar Statistical Characteristics and Early Warning Index of Yunnan Hail Disaster

利用云南省2006-2007年多普勒雷达产品及冰雹灾情资料,选取冰雹直径大于5 mm的22次灾害性冰雹天气过程进行分型统计。结果表明:云南春季南支槽影响型雹灾回波水平尺度大,回波核高度高,易出现典型钩状回波、弓形回波、"V"型缺口、弱回波区、悬垂结构等典型的超级单体特征;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾水平尺度、回波形状和垂直伸展高度均不如前者典型,但易出现三体散射现象。春季南支槽影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于6 km、30 d Bz水平尺度大于30 km、WER大于4 km、出现典型超级单体特征、速度场出现风场辐合、气旋性辐合、逆风区等、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于100%、出现中尺度气旋;夏季中纬度西风槽影响型和减弱的西行台风影响型雹灾的联合预警指标有回波强度大于50 d Bz、回波核高于4 km、30 d Bz水平尺度大于20 km、速度场出现风场辐合、气旋性辐合、逆风区等、出现三体散射现象、VIL出现明显跃增(最好大于30 kg/m2)、冰雹概率大于80%、出现中尺度气旋。

Using Doppler radar products and hail disaster data of Yunnan Province during 2006-2007 and se-lecting 22 hailing process with hail diameters greater than or equal to 5mm,the hail weathers are classified statisti-cally analyzed.Results show that,The Southern Branch trough type hails in spring has echo large horizontal scales and high kernel,as well as typical hook echo and bow echo and V notch and weak echo region and overhanging structure,on the other hand,the mid latitude westerly trough type and westward typhoon type hails in summer easy to produce three body scattering.In spring there are a few Joint early-warning index such as echo strength more than 50dBz,kernel higher than 6km,30dBz -horizontal scale greater than 30km,WER greater than 4km,typical supercell characteristics,wind field convergence,the cyclonic convergence,adverse wind area,VIL jump,hail probability greater than 100% and meso-scale cyclone;In summer there are still a few Joint early-warning index such as echo strength more than 50dBz,kernel higher than 4km,30dBz-horizontal scale greater than 20km,wind field convergence,the cyclonic convergence,adverse wind area,three body scattering,VIL jump,hail probability greater than 80% and meso-scale cyclone.