【目的】从天气学角度揭示北疆棉花严重障碍型冷害的致灾特点和成因,探讨其致灾机理,给出天气概念模型,为此类天气过程的预报提供参考和依据。【方法】以2001年7月28日~8月2日北疆棉花一次严重障碍型冷害天气过程为例,采用1°×1°NCEP再分析资料对其进行物理量的诊断分析。【结果】障碍型冷害天气过程的大气环流背景为100 hPa盛夏南亚高压及其北侧的副热带锋区上的低槽,南亚高压双体型致使副热带大槽位于中亚到新疆之间,造成新疆较大降水。500 hPa上,伊朗高压突然北挺,其高压脊顶向东北方向延伸,引导北方冷空气南下至中亚地区,形成深厚的冷性低值系统——中亚低涡,该低值系统深厚、稳定,其槽底伸到25°N,且低涡中心冷空气强度达-20.0℃,这在盛夏新疆较为罕见,从而造成持续性低温过程。高空西南急流对水汽输送起重要作用,它还可造成高空辐散,增强高空正涡度平流,从而使空气产生强烈的上升运动,为此次天气过程提供动力条件。【结论】南亚高压呈双体型分布,副热带大槽位于中亚至新疆之间,且大槽位置在40°N以南;500 hPa在中亚地区形成深厚冷性影响系统,冷空气中心强度在-20.0℃左右,新疆上空有较强的西南急流相配合,该天气形势在盛夏出现易造成新疆棉花严重障碍型冷害。 【Objective】 The objective of this study was to reveal the characteristics and causes of cold damage in severe cotton in north Xinjiang from a synoptic point of view, discuss the mechanism of its occurrence, provide a conceptual model of the weather, and provide a reference and basis for forecasting such weather processes. 【Method】 Taking the chilling injury course of a serious obstacle in northern Xinjiang as an example from July 28, 2001 to August 2, 2001, a 1 ° × 1 ° NCEP reanalysis data was used to diagnose and analyze the physical quantities. 【Result】 The atmospheric circulation background of the obstacle-type chilling weather process is the low trough of the 100 hPa midsummer SAH and its subtropical frontal zone on the north side. The south subtropical high trough caused the subtropical trough located between Central Asia and Xinjiang, Heavy precipitation. At 500 hPa, the Iranian high pressure abruptly went north and the high ridge extended northeastward, directing the northern cold air to the south of Central Asia and forming a deep cold low-value system, the Central Asia low vortex. The low-value system was deep and stable , With its groove bottom reaching 25 ° N and the cold air intensity at the center of the low vortex reaching -20.0 ° C, which is relatively rare in mid-summer Xinjiang, resulting in a continuous low-temperature process. The high-level southwest jet plays an important role in water vapor transport. It can also cause high-altitude divergence and enhance the positive vorticity advection at high altitude, resulting in a strong upward movement of air, providing dynamic conditions for this weather process. 【Conclusion】 The South Asian High is bisexual, subtropical big trough is located between Central Asia and Xinjiang, and the large trough is located south of 40 ° N. For 500 hPa, a deep and cold impact system is formed in Central Asia. The intensity of cold air center is between -20.0 ℃, there is a strong southwest jet over Xinjiang, the weather situation in midsummer easily lead to serious damage in Xinjiang cotton chilling injury.