Abstract: A thunderstorm disasters appeared in Shijiazhuang region from 15:00 to 18:00 on August 27, 2009. The mesoscale synoptic systems of this process such as gust front, squall line and mesocyclone and so on were detected by a Doppler radar at Xinle county of Shijiazhuang region. The characteristics of physical parameter field of this process and Doppler radar product were analyzed. The results show that unstable stratification of temperature inversion in the low level and vertical wind shear in the middle and low levels provide favorable conditions for strong convective development. Gust front has feedback action on the development of convective storm intensity. When gust front is moving away from the convective storm, the convective storm weakens or even dies out; when both are gradually close to each other, the convective storm strengthens or even develops into a supercell convective storm. Multiple single convective storm belt arrangement constitutes a squall line system, which brings wind speed spurt, wind zag, pressure upwelling and temperature falling. The supercell convective storm has the typical features of echoes with a “hook” shape, a “herringbone” shape, a “bow” shape, and deep lasting mesocyclone. The ground destructive wind is mainly brought by supercell convective storms.

Key words: Thunderstorm wind, Physical parameter field, Gust front, Squall line, Mesocyclone, Convective storm