2012年4月2日华东灾害性飑线大风成因分析

Causes Analysis of Severe Squall Line Wind in East China on April 2,2012

2012年4月2-3日华东地区出现8～11级灾害性大风，此次大风影响时间长，持续强度大，造成了严重的人员伤亡和经济损失。为探讨大风天气成因，运用传统的天气学方法和多普勒雷达等资料，对此次飑线大风过程产生的天气背景及中尺度发展演变特征进行了分析。结果表明，此次大风是由中尺度系统飑线和冷空气共同影响造成的。前期是在江淮气旋天气背景下，近地面激发出中尺度飑线系统，飑线经历了形成、发展、减弱三个阶段，在每个阶段，雷达强度图上的回波形状、强度、回波顶高，以及速度图上的逆风区、速度模糊等特征都与实况有很好的对应关系；在发展成熟阶段出现了冷湿雷暴高压和冷池，加剧了大风的发展和维持。后期大风主要是受冷空气影响产生。在实际业务工作中，传统的天气学分析方法和以多普勒雷达为代表的先进探测手段相结合，是监测和预警此类强对流天气的主要手段，能够在一定程度上弥补数值预报模式的不足。

During April 2 to 3, 2012, a 8-11 level disastrous wind which caused serious economic losses and disasters with long duration and high strength occurred in East China. By using traditional syn- optic analysis method based on Doppler weather radar data, the weather background and mesoscale evolu- tion characteristics of the squall line were analyzed. The results showed that the wind was caused jointly by both the mesoscale squall line and the cold air. In the formation stage, mesoseale squall line system formed on the surface against weather background of Jiang-huai cyclone. The radar echo shape, intensi- ty, echo top features in radar intensity charts and adverse wind area, radial velocity ambiguity features in velocity charts had a good correspondence with present situation in the stage of formation, development and weakening during squall line process. In the mature stage, cold and wet thunderstorm high pressure and cool pools exacerbated the development and maintenance of strong winds. In the final stage, the wind maintained by cold air. In service work, traditional synoptic analysis method combining with advanced detection means as Doppler radar was the main method for monitoring and warning strong convection weather, and can compensate some lack of numerical prediction models.