洛阳地区一次冰雹天气过程诊断分析

Diagnostic Analysis of a Hail Weather Process in Luoyang

利用常规气象观测资料、 NCEP1°×1°再分析资料, 对2016年4月27日发生在洛阳地区的一次冰雹天气进行分析.结果表明： 此次过程是在槽后西北气流背景下发生的, 槽后冷空气的入侵是冰雹发生的触发机制; 强对流天气水汽层结浅薄, 但其上升运动一般较为剧烈, 能在短时间内把水汽向上输送, 形成对流; 强对流天气出现在假相当位温和CAPE最大的区域与近地面冷平流最大区域重合的地带; 低层辐合高层辐散的形势配置有利于垂直上升运动加强, 强对流天气出现在垂直上升运动最强的区域.

Based on the conventional meteorological data and the NCEP 1°×1°reanalysis data, a hail weather process occurred in Luoyang area on 27 April 2016 was analyzed. The results showed that the process occurred in the back- ground of northwest airflow- and the invasion of cold air behind the trough was the trigger mechanism for the hail oc- currence. In strong convective weather the water vapor layer was shallow-, but the ascending motion was generally se- vere, and could transport water vapor upwards in a short time to form convective weather. The strong convective weather occurred in areas where the pseudo-equivalent potential temperature, the CAPE and the cold advection in the near ground were the largest. The low-level convergence and upper-level divergence were conducive to the en- hancement of vertical ascending motion, and the strong convective weather occurred in the areas with the strongest vertical ascending motion.