山西中南部一次暴雪过程诊断分析

Diagnostic Analysis of a Blizzard Process in South Central Shanxi

为了进一步分析山西中南部暴雪过程的形成原因,笔者利用常规和非常规气象观测与监测资料,针对2014年2月4—6日山西中南部暴雪天气过程,从高空、地面天气形势、中低层流型配置、雷达回波及物理量场的空间垂直剖面进行综合分析。结果显示：该次暴雪过程以500 h Pa西风槽、南支槽相继影响、地面倒槽前部东南气流的控制为背景。500 h Pa西风槽,700 h Pa西南急流与横切,850 h Pa东南急流为该次暴雪的中尺度有利配置。回波强度在15~30 d Bz,属连续均匀的稳定性降雪回波。物理量场的相对湿度在200 h Pa以下为大于80%的湿空气柱、对流层为一致的上升运动、高层辐散与低层辐合构成了有利于强降雪的环境条件。

In order to analyze the forming reasons of blizzard process in south central Shanxi Province,usingconventional and unconventional weather observation and monitoring data,the author analyzed a blizzardprocess during 4-6 February 2014 from aspects of sky and ground weather situation,mesoscale flow typeconfiguration,the vertical profiles of radar echo and physical field.Results showed that the blizzard processwas at 500 hPa westerly trough,influenced by the south trough,and controlled by the southeast airflow in frontof the ground inverted trough.500 hPa westerly trough,the 700 h Pa southwest jet and crosscutting,and 850 hPa southeast jet was the mesoscale favorable configuration for blizzard.Echo intensity was in 15-30 d Bz,belonged to the stability of continuous uniform snow echo.Physical quantity of wet air column under 200 hPa and 80% relative humidity,troposphere of consistent upward movement,high-level divergence and low-levelconvergence constituted the environmental conditions in favor of heavy snow.