Abstract: The differences of their characters and their influence on Weihai area in the aspect of circulation pattern,dynamic physical field diagnosis and thermal field diagnosis were mainly analyzed and compared. The results showed that the main factors affecting the intensity difference of the two typhoons were the intensity of the subtropical anticyclone and the interaction of westerly trough and subtropical system,water vapor flux condition and relative humidity condition transported to Weihai area,configuration of vorticity and divergence in typhoon environmental field,the increasing vertical velocity along with the landing of typhoon,invasion of the dry and cold air into the interior of typhoon in middle and high latitudes areas and so on. Among them,the larger vertical speed was the most greatly associated with the intensity of storms in Weihai area.

Key words: typhoon, storm, analysis and comparison, Weihai