摘要
从天气背景入手,结合多普勒雷达资料,分析2015年5月6日天气形势。结果发现:(1)此次过程主要为东北冷涡型,低层切变配合上干下湿不稳定层结,导致从西北地区来的对流云团到晋豫两省境内上空不断加强发展,最终形成飑线型风暴。(2)大气层结的不稳定性在K指数、CAPE值、SI指数、强的垂直风切变、近地面逆温层等方面均表现明显,0℃和-20℃层高度也有利于冰雹的产生。同时冷暖平流的垂直结构使得大气层结变得更不稳定。(3)>60 d Bz强回波中心先后以弓状回波—飑线—横倒着的"人"字型回波—飑线的形式演变,"人"字型的顶端位置对流发展最为旺盛。(4)此次过程为飑线型的风暴群。沿着雷达方向上有非常明显的"V"型缺口和三体散射,三体散射前后持续约2 h,回波特征为低层弱回波区上空的强回波悬垂。(5)回波顶高持续在11 km以上且范围大。此次过程是多个超级单体风暴组成的风暴群,强度大、面积广、持续时间长,在历史上实属罕见。
From the weather background, and taking into consideration the Doppler radar data, the authors analyzed the weather situation on May 6, 2015. The results showed that：（1） the process was mainly thenortheast cold vortex type, with a lower shear dry wet unstable stratification, which caused the convectiveclouds from the northwest to develop over Shanxi and Henan Province and ultimately formed the squall linestorm;（2） atmospheric stratification instability in the index K, CAPE value, index（SI）, strong vertical windshear, near surface inversion layer exhibited significantly, 0℃ and-20℃ layer height were also beneficial tohail formation, at the same time, the vertical structure of the cold and warm advection made the atmospheremore unstable;（3） 60 d Bz strong echo center successively evolved from bow echo-squall to line-cross to the＂people＂-shaped echo-squall line, the convection development in the top position of＂people＂was the mostexuberant;（4） the process was a storm group with squall line, along the radar direction there was a very obvious＂V＂type gap and three body scattering, which sustained about 2 hours, the echo characteristic was the strongecho hang in low layer weak echo area;（5） the echo top height was 11 km and had a wide range, the processwas a number of storm group composed of super monomer storms, which had big intensity, wide area, long duration, and it was rare in history.
出处
《中国农学通报》
2016年第23期122-127,共6页
Chinese Agricultural Science Bulletin
关键词
冰雹
强对流天气
不稳定层结
雷达
hail
strong convective weather
unstable stratification
radar
