黑龙江省α中尺度短时暴雨天气特征及成因分析

Analysis of the characteristics and causes of the α mesoscale short-term rainstorm weather in Heilongjiang

本文通过分析2017年8月6-7日高空、地面、自动站雨量等观测资料及NCEP FNL 1°×1°逐6 h再分析资料发现,本次短时暴雨天气过程是由于台风阻挡,低层低值系统移动缓慢,维持时间长且强度较强,配合低层暖脊及高空弱冷槽的不稳定层结条件和来自日本海洋面上的偏南水汽输送,在低压中心附近生成的α中尺度对流云团所产生的强对流天气,造成了黑龙江省南部短时间内暴雨级别的强降水。

Based on the observational data such as upper air, ground and automatic station rainfall data and NCEP FNL 1 ° ×1 ° reanalysis data for 6 hours from August 6-7, 2017, it is found that the short-term storm weather process is due to that the low pressure weather system moves slowly and sustains strong intensity for a long time because of typhoon blocking, combined with unstable stratification conditions of low warm ridges and weak cold upper air trough, and southward water vapor transport from the sea surface of Japan. The strong convective weather caused by α mesoscale convective cloud near the low pressure center resulted in heavy rainfall in the South of Heilongjiang in a short period of time.