连云港市冬季降水天气过程对比分析

Analysis and forecast of precipitation type in winter at Lianyungang

对连云港市近5 a冬季45个不同形态降水样本统计分析基础之上,利用常规天气图、物理量场以及新一代天气雷达资料,对发生在2007年冬季的三次不同形态(纯雨、雨夹雪、纯雪)降水天气过程进行了对比分析,归纳了冬季降水在物理量场及多普勒天气雷达图上的基本特征,总结了对降水形态预报具有指示意义的关键因子,同时探讨了连云港市冬季降水形态的预报着眼点,结果表明:降水区上空温度700 hPa是否低于-3℃、850 hPa是否低于0℃和地面温度是否小于3℃,以及雷达回波强度图上是否出现零度层亮带等,都可作为判断降水形态的重要指标。

Based on statistical analysis of forty five different precipitation types in recent five winters at Lianyungang, three different precipitation types （ rain, sleet, snow） in winter of 2007 are compared by synoptic map, physical parameters and Doppler radar data. Then basic precipitation features in physical parameters and Doppler radar echoes and the key factors for precipitation type forecasting are concluded, meanwhile, a viewpoint of forecasting precipitation type in winter in Lianyungang is discussed. The result shows that there are two key factors of precipitation type forecast. The first factor is whether temperature at 700 hPa, 850 hPa and on the ground is less than - 3 ℃, 0 ℃ and 3℃. The second factor is whether appearing the bright band on Doppler radar echoes.