基于SWCWARR模式的一次重庆江北机场对流天气过程分析

基于常规观测与雷达观测资料,应用西南区域数值模式SWCWARR和重庆RUC模式,对2019年4月27~28日重庆江北国际机场出现的一次强对流天气过程进行对比分析。结果表明：本次天气过程是高空槽后冷空气与低层西南暖湿气流相遇后形成切变,受地面辐合锋面和前倾槽系统共同影响的一次对流过程。SWCWARR模式的预报效果更优,该模式准确预报出了27日18时以后江北机场南部新生的对流单体,对其航线运行提供了良好的参考依据。本次天气过程中,低层西南风与强天气系统的发生发展具有显著正相关性,对强天气过程起到了很好的指示作用,尤其是重庆地区四面环山的地形特征产生狭管效应,强迫偏南风抬升增强,促进了该地区强对流天气的发生发展。

Analysis of a Strong Convective Weather Hazard in Chongqing Jiangbei Airport Based on SWCWARR Model

Based on the conventional observation data and the radar data, the regional model of Southwest China (SWCWARR) and Chongqing Rapid Updata Cycle (RUC) model were used to comprehensively analyze a severe convective weather process that occurred at Chongqing Jiangbei International Airport from 27th to 28th April 2019. The results show that this convective process was impacted by the surface convergence front, forward trough and the vertical shear caused by the intersection of the southwest warm air and the cold air behind the upper trough. SWCWARR model showed obvious superiority. It is worth mentioning that the newly formed convective cells in the south of the airport were accurately predicted by SWCWARR model after 18UTC on 27th, which provided a useful reference for the operation of the southern route. Moreover, the diagnostic analysis of some physical quantities based on SWCWARR model showed that the low-level southwest wind had a high positive correlation with the occurrence and development of severe weather system. In particular, the narrow tube effect caused by the topography in Chongqing forced the southwest wind to lift and strengthen, which promoted the occurrence and development of severe convective weather in this area.