宿州市一次强对流天气的特征分析及预报检验

Characteristic Analysis and Forecast Verification of a Severe Convective Weather in Suzhou City

利用常规高空和地面观测资料、区域自动站资料、多普勒天气雷达以及数值模式预报产品,从弥补短期预报的不足、提前服务以减轻其造成的灾害损失的角度出发,对宿州2021年6月30日一次强对流天气过程的天气背景、环境条件及触发机制进行系统分析。结果表明:此次过程500hPa形势是蒙古冷涡、东北冷涡的形势下配合高空浅槽东移,700hpa和850hpa切变线位于宿州北侧。强对流天气发生前大气层结极不稳定,上干冷下暖湿的垂直空间分布有利于对流不稳定层结的建立。多普勒雷达观测表明,此过程回波最强强度为66dBz,19∶14出现的阵风锋、22∶11出现的弓形回波和低层径向速度大值区与出现大风的区域有很好的对应。ECMWF、NECP等全球模式对大尺度稳定降水落区预报表现较好,但对其中对流天气组织化描述不足。GRAPES_3KM、华东区域等中尺度模式稳定性不如全球模式,但对对流尺度天气预报有优势。

Using conventional high-altitude and ground observation data,regional automatic station data,Doppler weather radar and numerical model forecast products.From the aspects of making up for the short-term forecast and providing services in advance to reduce the disaster losses caused by it,a systematic analysis of the weather back⁃ground,environmental conditions and triggering mechanism of a severe convective weather process in Suzhou on June 30,2021.The result shows:The 500hPa situation in this process is the Mongolian cold vortex and the northeast cold vortex,with the high-altitude shallow trough moving east,and the 700hpa and 850hpa shear lines are located on the north side of Suzhou.Combined with the analysis of environmental conditions,it is found that the atmospheric stratification is extremely unstable before the occurrence of strong convective weather,and the vertical spatial dis⁃tribution of upper dry and cold lower warm and wet is conducive to the establishment of convective unstable stratifi⁃cation.Doppler radar observations show that the strongest echo intensity in this process is 66dBz,the gust front at 19∶14,the bow echo at 22∶11,the low-level radial velocity large value area and the strong wind area are very good.correspond.Comparative analysis of the results of multiple numerical forecasts shows that global models such as EC⁃MWF and NECP perform well in large-scale stable precipitation areas,but the organized description of convective weather is insufficient.Mesoscale models such as GRAPES_3KM and East China are not as stable as global models,but they have advantages for convective-scale weather forecasting.