Abstract:
Based on the routine data, NCEP data, satellite images, radar data, and the dens
ified observations, a dynamical diagnosis of the convect
ion torrential rain in south of cold front on 28 May 2008 in the northern part o
f Jingxi Province is ma
de. The results show that (1) the convection torrential rain south of cold front
was due to the several main reasons, such as, all nearly vertical troughs
at various levels, precipitous front surfaces, forwardedtilting trou
gh structure, extremely
strong lower warm and wet air flows ahead of the cold front, greatly increased
unstabl
e energy of the convection formed by warm, wet below and dry, cold above convect
ions, and the lowlevel southwest jet stream strengthening when the cold front
moving closely and cyclone wave moving east. All of these factors resulted in t
he unstable energy release from the convection. (2) This torrential rain showed
the characteristics on obvious meso and small scales that had four mesoβ scale convection systems moving to the
east along the ground cold front. The gr
ound mesoscale cy
clone, the mesoscale convergence line, the strong echo area, the head wind zon
e, and the 850hPa mesoscale convergence line, all demonstrated the presence of
the mesoscale perturbation. Furthermore, mesoscale perturbation was well corre
lated to the convective rain cluster.