河北省中南部一次大雾天气过程分析

对2003年11月河北省中南部大雾天气进行了分析，结果表明与稳定度有关的物理量场的变化不仅是强对流等灾害性天气的预报指标，对大雾天气也有一定的指示意义：雾是在稳定的大气层结下出现的天气现象，根据大气稳定层结的状况及变化，可以判断大雾天气的有无及其生消时间。另外，前期湿度条件的积累也是影响大雾生成的主要原因。

Analysis of Heavy Fog in Southern Hebei Province

An analysis of the heavy fog which appeared in southern Hebei Province from the mid-night of 28 to the noon of 29 November in 2003 is made.The results show that the physical elements relating to stability are the indexes not only of severe convection process,but also of heavy fog.Fog is a weather phenomenon which comes forth in steady atmosphere. From the stratification and change of the atmosphere, a heavy fog appearing or not,as well as the growing or vanishing time can be decided.In addition,the humidity's accumulation is a cause affecting the heavy fog making also.