2018年1月25—28日岳阳低温阴雨雪过程成因分析

Analysis of the Cryogenic Freezing Rain and Snow Weather Process in Yueyang Betw een J anuary 25^(th) and 28^(th)

利用常规观测资料和NCEP再分析客观物理量场、多普勒雷达产品资料,就2018年1月25—28日岳阳市低温阴雨雪天气过程的形成原因进行了分析,指出当地连续性低温阴雨雪天气发生的环流形势特征及演变,总结了应用数值预报产品的经验以供借鉴。结果表明:在500 hPa和700 hPa环流形势稳定的情况下,降雪地区的位置与850 hPa^925 hPa的辐合区位置相对应;活跃的水汽输送,较强的辐合可以使雨雪天气得以维持;低层冷空气对冬季降水相态具有关键性作用。

Based on the conventional observation data and the NCEP reanalysis data as well as the Doppler radar data, the forming reasons of cryogenic freezing rain and snow weather process in Yueyang between January 25th and 28th were analyzed. The circulation situation characters and evolution which was caused by succession cryogenic freezing rain and snow weather in this district were pointed out, and the experience of using data broadcasting were also concluded, which get some referential experience. The results showed that under the stable condition of 500 hPa and 700 hPa circulation situation,the location of snowing was corresponding to convergence zone between the 850 hPa and 925 hPa $ and the active vapor transportation and the stronger convergence could keep the raining and snowing continues; and the lower cold air could be the critical effect to the precipitation phrase in winter.