采用常规观测资料、NCEP逐6 h1º伊1º再分析资料、FY-2D云图资料，对2014年8月16—19日伊犁河谷持续降水过程进行天气动力学分析。结果表明：持续降水发生在100 hPa南亚高压呈典型的双体型、500 hPa伊朗副高—中亚低值系统—贝加尔湖阻滞脊稳定维持的环流背景下，中亚低槽前的偏南气流将阿拉伯海、孟加拉湾的水汽通过接力输送机制输送到伊犁河谷。200 hPa强盛的西南急流，低层辐合、高层辐散抽吸的散度场，上升运动区与正涡度区叠加的动力结构利于持续降水的形成。降水明显时段，800 hPa以下受负湿位涡控制，有条件性对称不稳定。强降水时段的云顶亮温TBB最低值在-48℃左右。持续降水导致伊宁市8月降水量（45.8 mm）突破1952年以来的同期历史极值。%A persistent precipitation process in Yili in August 2014 is diagnosed based on conventional observation data, NCEP daily reanalysis data, and FY-2D satellite data. The results show that the circulation background and weather condition of the persistent precipitation is the stable maintaining of double centers distribution of South Asia high pressure at 100 hPa, Iran subtropical high pressure, low pressure system over Central Asia, and blocking ridge over Lake Baikal at 500 hPa with a continuous supply of vapors from the Arabian sea and the bay of Bengal by the south airflow in front of Central Asia low trough.The dynamical structure, 200 hPa strong southwest jet, convergence (divergence) on low (high)-level in divergence field, the overlay of ascending motion and positive vorticity regions, is conducive to the formation of the persistent precipitation. During the heavy precipitation period, it is conditional symmetric instability with negative moist potential vorticity under 800 hPa and the minimum value of Black Body Temperature (TBB)on cloud top is about -48 ℃. Persistent rainfall was the most important component of the total precipitation in August 2014 in Yining (45.8 mm) which broke the record of total precipitation in August since 1952.
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