Abstract:By using the (1°×1°) reanalysis data of NCEP and the data of upper air sounding and surface observations, the thermal and dynamical features of a heavy dust storm occurring on 24 April 2010 in the Hexi Corridor are analyzed. The calculated results show that before the dust storm occurs, the sensible heat flux reaching the maximum value increased the atmospheric instability. The gale and dust storm are in accordance with the great value area of the momentum flux, and the momentum flux plays an important role in the transporting upwards dust. Nearby the strong frontal zone, the geostrophic balance is destructed, the dust storm mainly appears in the area of great allobaric gradient and the allobaric wind is the principal constituent of the surface gale. This heavy dust storm is a process of strong frontogenesis and the latter causes the frontal secondary circulation strengthening. The greater the negative (absolute) value of horizontal helicity is, the greater the surface wind speed will be. The gale and dust storm mainly appear between the right front of the horizontal helicity negative value center and zero contour. The upper level jet traversing geopotential height surface along isentropic surface slides down to 2000 gpm and forms the westerly low level jet. The low level jet plays a crucial role in the producing process of the dust storm.