摘要
使用2003—2005年4—8月发生在宜昌境内17次冰雹个例资料和相应的多普勒天气雷达(CINRAD/SA)产品资料,采用雷达产品特征分析和参量相关分析方法,对反射率产品、速度产品、回波顶高以及其他主要导出产品对冰雹预警的适用性进行了分析。结果表明:(1)反射率因子出现前侧V型槽口时,上升气流强烈,出现冰雹的可能性大。(2)降雹一般发生在正负风暴平均相对径向速度(SRM)对出现且其辐合最强时。(3)回波顶高达到9 km以上可作为冰雹发生的参考条件。(4)当垂直积分液态含水量(VIL)密度超过4 g.m-3,出现直径超过2 cm大冰雹的可能性极大。(5)冰雹指数(HI)对冰雹预警有一定指示意义;中气旋(M)出现可发布雷雨、冰雹、大风等强天气警报;龙卷涡旋特征(TVS)出现,可考虑发布冰雹和大风的强天气警报,但需参照反射率和速度产品进行具体定位。
Based on the 17 hail cases occurred in Yichang from April to August during 2003-2005, CINRAD/SA radar products＇ applicability on the early-warning was analyzed by means of the radar products features analysis and the parameter correlational analysis. The forth-flank notch in the reflectivity product indicated the strong updraft and the great probability of hail. Hails generally occurred when the average relative radial velocity couple of positive and negative storm （SRM） appeared and the convergence was the strongest. It＇s a reference qualification of hails occurring that the convection Echo Tops （ET） height is up to 9 km. Moreover, there is a great probability of big hail whose diameter might be over 2 cm when VIL density is 4 g·m^-3 and more. The Hail Index （HI） has a certain extent indication for hails＇ early-warning. Once the Mesocyclone （M） appears, a severe weather （including thunder storm, gale, and hail） alarm signal can be promulgated. When a Tornado Vortex Signal （TVS） appears, the gale and hail alarm could be promulgated. The reflectivity and velocity products can help to position the severe weather.
出处
《暴雨灾害》
2008年第3期268-272,共5页
Torrential Rain and Disasters
基金
湖北省科技攻关项目"长江中游短时天气预警报业务系统(MYNOS)"资助
