呼伦贝尔市2019年8月20-21日暴雨天气诊断分析

文章对2019年8月20-21日东北冷涡引发的大范围暴雨天气成因进行诊断分析,结果表明:此次呼伦贝尔市大范围暴雨以稳定性降水为主、对流性降水为辅,表现为小时雨强不大,但持续时间长;暴雨区有较深厚的上升运动但强度较弱,强降雨区与强烈的上升运动区并不重合;降雨期间虽然有持续的低空急流向降雨区输送水汽和能量,但是850 h Pa比湿大部分时间维持在本地暴雨阈值10 g·kg-1以下;由于暖湿空气强、冷空气弱,所以对流有效位能小,对流强度弱;大兴安岭山脉迫使东南暖湿气流强迫抬升,对降雨起到促进作用。

Diagnostic Analysis of Heavy Rain in August 20-21, 2019, Hulunbeier City

This paper analyzes the case of the heavy rain caused by the northeast cold vortex from August 20 to 21,2019.The results show that the heavy rain in the Hulunbuir is mainly stable precipitation,supplemented by convective precipitation.The hourly rain is not strong,but it lasts for a long time.The rainstorm area has deeper ascending movement but weakerintersity,and the strong rainfall area does not coincide with the strong ascending movement area.Although there is a continuous low-level jet to transport water vapor and energy to rainfall,the 850 hPa specific humidity remains below the local rainstorm threshold of 10 g•kg-1 for most of the time.Because of the strong warm air and the weak cold air,the effective potential energy of convection is small,so the intensity of convection is weak.The Greater Khingan forces the warm,moist air in the southeast to lift up,which promotes rainfall.