Analysis on an Unusual Snowstorm Event Caused by Explosive Cyclone

A snowstorm event caused by explosive cyclone happened in Liaoning Province in March 3-5,2007.The cyclone caused heavy snow,strong winds and low visibility,which had large influences on the traffic,particularly on aviation.The authors analyze the process from the large-scale circulation,mobile path and intensity of the cyclone,moisture conditions,cold and warm air,etc.The results show that strong baroclinic wave is the main reason for the development of the explosive cyclone,and that high potential vorticity in the stratosphere promote the development,too.High-?and low-level jets,divergence field,vertical movement constitute a strong secondary circulation.The snowstorm in Shenyang is closely related to the movement of cyclones path,water vapor transport and the degree of vertical movement.