乌鲁木齐机场一次间歇型大到暴雪天气特征分析

Characteristics Analysis of an Intermittent Heavy Snowstorm at Urumqi Airport

本文利用乌鲁木齐机场常规观测资料、微波辐射计资料及美国环境预报中心(NCEP)的1˚ ×1˚再分析资料对2019年12月22~24日一次间歇性大到暴雪天气过程进行研究分析,结果表明:1) 此次降雪过程,为西西伯利亚低槽引导高纬度冷平流南下,自西向东影响新疆地区。2) 两次降雪过程,水汽都是以接力的方式输送,巴尔喀什湖为降雪的主要水汽输送源。3) 水汽通量散度辐合区和垂直速度上升区配合较好的时段对降雪开始时间有一定的预报提前量。水汽通量散度辐合区较弱,且没有垂直上述运动配合,可以判断为降雪的间歇期。4) 微波辐射计相对湿度和绝对湿度廓线大值区主要位于3000米以下,湿度明显增大和减小的时间与降雪时段吻合较好。此次降雪有10小时的间歇期,间歇期的预报可为机场正常运行提供决策支持。

This paper used the routine observation data of Urumqi airport, the microwave radiometer data and 1˚ ×1˚ reanalysis data of the National Center for Environmental Prediction (NCEP) studied and analyzed an intermittent heavy snowstorm weather process on December 22~24, 2019. The results showed that: 1) the snow process led the high latitude cold advection southward for the low trough of West Siberia, and affected Xinjiang from west to East. 2) During the two snowfall processes, water vapor was transported by relay, and Balkash lake was the main water vapor transport source of the snowfall. 3) Advance forecast for the start of snow when the water vapor flux divergence convergence area and the vertical velocity rise area cooperate well. The convergence area of water vapor flux divergence was weak, and no vertical movement coordination, so it can be judged as the intermittent period of snow. 4) The maximum area of the relative humidity and absolute humidity profile of the microwave radiometer is mainly below 3000 meters, and the time when the humidity increases and decreases obviously coincides with the snowfall period. The snowfall had 10-hour intermission. The forecast of the intermission can provide decision support for the operation of the airport.