Feature of Doppler radar data about a squall line strong wind in north of Shanxi Province

By using the basic reflectivity factor,the composite reflectivity factor,the speed profile map,the vertical liquid water content,the echo tops and the vad wind profile of Doppler radar products for Datong area of the north of Shanxi Province,and combined with circulation situation and automatic weather station data,this paper analyzes a squall line process happened in Datong area on June16,2010.The results show that the squall line process occurred at high,middle and lower layers cold vortex circulation situation;Atmospheric pressure,temperature and wind velocity alter sharply when squall go through.In studying the stations with maximize wind speed ≥16.8 m·s-1,it is discovered that the time occurring maximum velocity in two stations is in accord with that of outflow boundary effect,the time of,maximum velocity value in four stations correspond to sink effect time of powerful echo;The cold air carried by cold eddy makes the air flowing into the tail of squall to be continuously added,but the warm moisture flow in front side continuously produce a new single body,and that is the main reason of maintenance and development of squall line.