云南昆明机场一次强降水天气过程诊断分析

Diagnostic Analysis of a Heavy Precipitation Weather Process at Kunming Airport, Yunnan

摘要: 利用NCEP FNL再分析资料、雷达基本反射率资料对2017年7月1~3日发生在云南昆明的一次强对流天气引起的强降水天气过程进行诊断分析，结果表明，本次昆明机场出现的强降水过程具有突发性强、持续时间长以及破坏力大的特征，500 hPa上为槽后西北气流引导冷空气南下，而在700 hPa上在云南省北部地区由于西南涡的影响有一浅槽，且自湖南省南部至云南省北部之间有一切变线，并逐渐影响昆明地区，为强对流天气提供了较好的动力条件。高层干冷、中低层暖湿的配置加大了气层的不稳定性，加之地面上锋面过境，为此次昆明地区强对流天气提供了有利的环流形势。强降水开始前降水区中低层大气具有较好的水汽条件，处于水汽通量散度大值区，有显著的水汽辐合，在垂直方向上大气湍流运动较强，也为此次强对流天气提供了较好的条件。

Abstract: Using NCEP FNL reanalysis data and radar basic reflectivity data, a heavy precipitation weather process caused by a strong convective weather in Kunming, Yunnan Province from July 1 to 3, 2017 was diagnosed and analyzed. The results show that the heavy precipitation process at Kunming Airport has the characteristics of strong suddenness, long duration and great destructive power. At 500 hPa, the northwest airflow behind the trough leads the cold air to move southward, while at 700 hPa, there is a shallow trough in the northern part of Yunnan Province due to the influence of the southwest vortex, and there is a shear line from the southern part of Hunan Province to the northern part of Yunnan Province, which gradually affects Kunming area. It provides good dynamic conditions for strong convective weather. The configuration of high-level dry and cold, middle and low-level warm and humid increases the instability of the atmosphere, and the frontal transit on the ground provides a favorable circulation situation for the strong convective weather in Kunming. Before the beginning of the heavy precipitation, the middle and lower atmosphere in the precipitation area had good water vapor conditions. It was in the large value area of water vapor flux divergence, with significant water vapor convergence, and strong atmospheric turbulence in the vertical direction, which also provided good conditions for the strong convective weather.