乌鲁木齐天山国际机场一次春季强降水天气分析

Analysis of a Spring Heavy Precipitation Event at Urumqi Tianshan International Airport

摘要: 本文利用NCEP 1˚ × 1˚逐6小时再分析资料和雷达资料，对2025年5月2~3日乌鲁木齐天山国际机场春季强降雨天气特征及成因进行分析，结果表明：(1) 乌拉尔槽底前部偏西气流、低层西北急流、叠加地面强锋区共同作用，在沿天山一带产生强烈的垂直上升运动和地形强迫抬升作用，为强降水提供良好的动力条件。(2) 中低层中亚–北疆沿天山一带有稳定的水汽输送带，伊犁河谷、天山山区有水汽辐合中心，且水汽达到饱和，为两场降水提供充足的水汽条件。(3) 本场上空上层有辐散中心，中低层配合有辐合中心，使得本场上空维持有深厚的上升运动，提供了良好的动力条件。(4) K指数、SI指数具有较强的对流潜势，以及混合性降水回波，造成伊犁河谷、天山山区局地出现短时强降水和大风天气。

Abstract: This study analyzes the characteristics and causes of a spring heavy rainfall event that occurred at Urumqi Tianshan International Airport from May 2 to 3, 2025, using NCEP 1˚ × 1˚ 6-hourly reanalysis data and radar data. The results show that: (1) The combined effects of the westerly airflow in front of the Ural trough bottom, the low-level northwest jet stream, and the surface strong frontal zone generated intense vertical ascending motion and topographically forced uplift along the Tianshan Mountains, providing favorable dynamic conditions for heavy precipitation. (2) There was a stable water vapor transport belt in the middle and low levels over the area from Central Asia to northern Xinjiang along the Tianshan Mountains, with water vapor convergence centers in the Ili River Valley and the Tianshan Mountainous Area; the water vapor in these regions reached saturation, supplying sufficient moisture for the two rainfall episodes. (3) A divergence center existed in the upper layer above the airport, while a convergence center was present in the middle and low layers. This configuration maintained deep ascending motion over the airport, offering favorable dynamic conditions. (4) The K-index and SI index indicated strong convective potential, and the mixed precipitation echo led to the occurrence of short-term heavy rainfall and gale weather in local areas of the Ili River Valley and the Tianshan Mountainous Area.