Abstract:By using sounding and ground in situ observation data, GPS/MET and FY-2E satellite data, NCEP/NCAR reanalysis data(1°×1°), two severe rainfall events, which occurred on the edge of subtropical high belt in south Shandong, are analyzed. The results show that two heavy rainfall processes were both caused by weak westerly trough on the edge of the subtropical high at 500 hPa, as the subtropical high belt strengthened and moved westward inducing southwesterly jets between 850-700 hPa. Both heavy rainfalls occurred in the front of the southwesterly low level jets, and near the warm shear lines. As the low level southwesterly jets intensified and invaded northward, heavy rainfalls began, and while the jets weakened, the rainfalls eased. The torrential rain region has good consistency with the high value regions of CAPE, water vapor flux, convergence of water vapor and low level warm advection. The southwesterly low level jet and atmospheric precipitable water retrieved from GPS/MET are indicative for short-time heavy rainfall forecast. The minimum TBB of convective cloud clusters were -78- -62 ℃,corresponding hourly maximum rainfalls 40-90 mm. During the heavy rainfall process, a mesoscale vortex occurred below 850 hPa with weak low pressure but significant cyclonic circulation. The most intense rainfall was generated at the center of warm advection in the southeast of the vortex at 925 hPa. During the first heavy rainfall process, the mesoscale vortex moved less, while stronger rainfall was induced by stronger upward movement in the southeast of the vortex. During the second strong rainfall process, the low level cold air invaded from northwest into the vortex resulted in a cyclone, which moved northeastward. Large precipitation was produced in the warm zone in front of the cold front.