乌鲁木齐机场一次长时间雷雨天气特征及成因分析
Analysis of the Characteristics and Causes of a Long-Term Thunderstorm at Urumqi Airport

利用NCEP逐6小时的1？ × 1？再分析资料、新疆区域加密自动气象站逐十分钟观测、常规高空及地面观测资料、多普勒天气雷达探测资料，对2023年5月22日乌鲁木齐机场长时间雷雨天气过程特征及环境场诊断分析。结果表明：1) 此次雷暴天气过程发生在西伯利亚低涡南压、宽广槽底不断分裂的短波槽东移的大尺度环流背景下，呈现持续时间长、尺度小且移动速度快等特点。2) 机场多普勒雷达回波演变反映出多个对流单体在移动中合并有利于整个回波云团快速发展，在高空引导气流的作用下，影响本场及终端区。3) 本场中低层水汽辐合条件较好，长时间维持的水汽辐合区有利于水汽汇聚，为雷暴天气的发生提供了良好的水汽条件。4) 地面辐射增温配合高层弱冷空气入侵，形成“上干下湿”的垂直结构，配合较大的对流有效位能，加速对流的触发。“高层干冷、低层暖湿”的垂直配置，会加强雷暴单体的发生发展。5) 雷暴发生前，高层辐散、低层辐合的高低空配置，使垂直上升运动加强，上游地面辐合线的发展东移是本场雷雨天气的触发机制之一。
This article diagnoses the characteristics and environmental field of the long-term thunderstorm weather process in Urumqi Airport on May 22, 2023, by using NCEP every 6 hours of 1？ × 1？ reanalysis data, Xinjiang regional encrypted automatic weather station 10-minute observation, conventional high-altitude and ground observation data, Doppler weather radar detection data. The results show that: 1) This thunderstorm weather process occurred under the large-scale circulation background of Siberian vortex presses southward and short-wave trough at the bottom of the wide trough moves eastward, which is characterized by long time, small scale and fast moving speed. 2) The echo evolution of airport Doppler radar reflects that the merging of multiple convective cells in the middle is beneficial for the rapid influence of the whole echo cloud cluster. Under the guidance of high-altitude airflow, echo affects the local and terminal areas. 3) The water vapor convergence zone in the middle and lower layers of this field, which is maintained for a long time, is beneficial to water vapor convergence and provides a good water vapor condition for thunderstorm weather. 4) The vertical structure of “dry at the top and wet at the bottom” formed by the surface radiation warming combined with the invasion of weak cold air at the upper level and the large convective effective potential can accelerate the triggering of convection. The vertical configuration of “dry and cold in the upper floors, warm and humid in the lower floors” will strengthen the occurrence of thunderstorm cells. 5) Before the thunderstorm, the upper level divergence and the lower level convergence made the vertical ascending motion strengthen, and the eastward development of the upstream ground convergence line was one of the triggering mechanisms of this thunderstorm weather in this field.