连云港市一次强对流暴雨天气分析

Analysis on a Severe Convective Rainstorm Weather in Lianyungang

[目的]分析连云港市一次强对流暴雨天气的成因和数值预报检验。[方法]利用常规和非常规气象资料,从天气背景、稳定度及触发机制等方面对2015年8月7日连云港市的一次强对流暴雨天气过程进行系统分析,并对比分析各家数值预报结果。[结果]此次强对流暴雨发生在副高西伸北抬、高空槽东移的大尺度背景下,暴雨发生前大气层结不稳定、边界层辐合是触发不稳定能量释放的主要因素;多普勒雷达观测表明,回波强度在50 d Bz左右,与边界层辐合线位置对应较好;对比分析各家数值预报结果表明,数值预报对不稳定性降水预报效果较差。[结论]该研究为此类强对流暴雨天气的预报提供科学依据。

[Objective] The research aimed to analyze the cause and numerical forecast test of a strong convection rainstorm weather in Lianyungang.[Method]The severe convective rainstorm process occurred on August 7of 2015 in Lianyungang City was analyzed by using conventional and non- conventional meteorological data from weather background,stability and the trigger mechanism,and the various numerical prediction results were analyzed contrastively.[Result]The strong convective rainstorm occurred in the west and north stretch of the SUBH and upper trough eastward under the background of the large scale,the atmospheric stratification being extremely unstable before rainstorm and the boundary layer convergence were the main factor triggering instability energy release. Doppler radar observation indicated that the intensity of precipitation echo was above 55 d Bz,the boundary layer convergence line corresponds to the position of strong echo better. Comparative analysis of various numerical prediction results show that the forecast effect of the numerical prediction was poorer for instability precipitation.[Conclusion]The study provides the scientific basis for the strong convection rainstorm weather forecast.