Analysis of Two Hailstorm Processes Accompanied with Weak Precipitation in the North of Shandong

摘要

Based on conventional observation data, wind profile radar data and data obtained by a microwave radiometer, the formation mechanisms of two hailstorm processes accompanied with weak precipitation in the north of Shandong Province on June 8 and July 1 in 2014 were analyzed. The results showed that energy accumulated before the occurrence of two hailstorm processes. That is, the height of 0 and -2 0 ^ layer dropped rapidly in the period of hailing, and the height of 0 ^ layer was around 2.2 km. Echo clusters producing hail still belonged to meso-y scale-meso-p scale, and the intensity of reflectivity factor exceeded 50 dBz； echo top was at 12 -1 4 km, and vertically integrated liquid water content was over 30 kg/m2 ； in the two processes, water accumulation zones were distributed at 0.6 - 2.0 km. In addition, the water vapor conditions of low-level environmental fields were poor, which resulted in small rainfall in the two processes. However, there were significant differences between the two processes in terms of influencing systems, motion path of hail, changes of ground meteorological elements and disasters. The influencing systems of the "608" process were the cold vortex, transverse trough and cold front. Convective clouds moved from the northwest to the southeast, and ground temperature dropped, while dew point and ground pressure rose； wind direction changed suddenly with the movement of cold front, and there was no disaster. The influencing systems of the 1170111 process were the upper trough, shear line and convergence line. Convective clouds moved from the south to the north. When convective clouds moved to the station, ground temperature dropped, and there was no obvious change in dew point； ground pressure declined sharply, and wind speed was small, but wind direction was changeable, so that the local direct economic loss was up to about 0.2 billion yuan.