2017年7月豫北一次雷雨大风过程成因分析

Analysis of Thunderstorm Causes in the July 2017

通过对2017年7月9日夜里发生在豫北地区的雷雨大风强对流过程进行综合分析可知： 高空东移冷槽和低层暖脊叠加造成较强的大气层结不稳定, 有利于雷雨大风强对流天气的出现; 同时, 强对流天气发生前, 0～6km垂直风切变达到中等偏强程度, 有利于对流系统的形成和维持; 边界层辐合线和雷暴外流边界是主要触发机制.

The strong convection process of thunderstorm and strong wind occurred in the north of Henan Province in July 9, 2017 night was analyzed comprehensively. The results showed that the superposition of the cold trough and the low layer of warm ridge caused the strong atmospheric instability, which was beneficial to the occurrence of heavy wind and strong convective weather,. At the same time, the vertical wind shear of the 0 - 6km reached the moderate intensity before the severe convective weather occurs, which was conducive to the formation and maintenance of the convective system. The boundary layer convergence line and the thunderstorm outflow- boundary was the main triggering mechanisms; there was a deep middle radial convergence zone at the high altitude of 3 - 8km, and the existence and stability of the counter wind zone indicate the occurrence of short time strong precipitation.