Synthetic Analysis on a Squall line in Northwest Hubei on June 1,2008

Based on 1°×1° 6 h re-analysis data from NCEP,conventional observation data and Doppler radar data,a squall line over Shiyan city of northwestern Hubei from afternoon to evening on 1st June 2008 is analyzed by using the synoptic and dynamic diagnostic method.The results show that the main influence systems of the squall line are the cold trough at the upper level,the shear line in the low-level and the cold front on the ground,and the triggering mechanism of the severe convection event is the meso-scale convergence line on the ground.At the same time,instability energy of the air column is strengthened as the incursion of dry and cold air of upper level,which is an important role in the development of severe convective weather.Characteristics of squall line are showed better by Doppler radar data in particular,and the severe convective area had a better corresponding relation with the storm center on squall line.