内蒙古通辽地区冰雹天气的雷达回波判别指标

Discriminant Index of Radar Echo for Forecast of Hail Weather in Tongliao Area of Inner Mongolia

通过对内蒙古通辽市新一代天气雷达建站以来至2013年发生在通辽地区的冰雹天气过程,以及各种雷达回波产品在冰雹发生前一段时间内的表现特征以及探空资料进行分析可知:雷达反射率因子产品的钩状回波、"V"型缺口和三体散射(即长钉状回波)、弓形回波、"人"字形回波(LEWP)和菱形回波等特征,径向速度图上明显的辐合场或辐合带、"中气旋""逆风区"等特征,以及回波顶高,VAD风廓线产品,垂直积分液态含水量,中气旋产品,强度和速度的剖面图等都有指示意义的表征,并且通过以上特征总结出相应的量化指标,作为未来是否会有冰雹出现的判断依据,应用到实际的短时临近预报工作中,以期提高冰雹的预报预警能力。

In the present study, we analyzed the hail weather process occurred in Tongliao region of Inner Mongolia from the establishment of the new weather radar station to the year of 2013 and assessed the features of radar echo products obtained a period before the occurrence of hail as well as the radiosonde data. We found that the following features of the radar echo products all had an indicative significance for the forecast of hail weather： the hook echo of radar reflectivity factor, V-notch, three scattering （spike-shaped echo）, bow-shaped echo, herringbone echo （LEWP）, diamond echo; the convergence field or convergence zone, mesocyclone, and adverse wind area in radial velocity map; echo top height, VAD wind profile products, vertically integrated liquid water content, mesocyclone products, profile of intensity and velocity. Based on the above features, we summarized the corresponding indicators which could be used as a judgment basis for the forecast of hail weather in the practical work of short-term forecast and nowcasting to improve the forecasting and warning capability for the hail weather in Tongliao region.