Based on the radar data in Hanzhong from June to August during 2013-2017 and the convective zone on constant altitude plan position indicator by using discrimination method, the characteristics of convective activities were analyzed during the warm season in and around Hanzhong areas. The results show that the high frequency areas of convective activities were mainly located in the Daba mountains, the southeastern foothills of the Qinling mountains and the transitional zone of the eastern QinlingDaba mountains around Hanzhong city, the highest convective frequencies and the widest areas were in the Daba mountains, followed by the southeastern foot of the Qinling mountains and the transitional zone of the Qinling and Daba mountains, and convective frequency was least in the western part of the Hanzhong basin. The convective activity was most in July and least in June, and convective frequency and convective areas showed obvious diurnal variation. The locations of convective high frequencies areas were highly correlated with mountainous terrain features. The high convection frequencies areas in the Daba mountains nearly coincided with terrain heights, while the high value areas in the southeastern foothills of the Qinling mountains were located on mountain slopes. The convection extension height was mostly below 7 km, with the highest proportion at a height of 4 to 5 km. Based on the reanalysis data, it was found that the convective instability energy maintained a high value center in the eastern part of the Sichuan basin in July and August, which was very close to the Daba mountains in the north of it, and it may be one of the contributing factors to the persistence of the local high convective region.

 Weather radar is an atmospheric remote sensing detection equipment used to detect weather phenomena and meteorological elements in the atmosphere. The study of radar climatology can help us understand the temporal and spatial distribution and evolution characteristics of convective storms and convective precipitation, as well as the occurrence frequency and storm properties of strong weather. The new progresses were reviewed as follows: (1) The research progress of radar climatology of convective storms mainly revealed the daily cycle and spatial variation characteristics of convection, and analyzed the relationship between the formation, strengthening and characteristics of the daily cycle of convection and solar radiation heating, topography and mesoscale system activities. (2) The research of radar precipitation climatology mainly focused on the characteristics of precipitation in different regions, the characteristics of different types of precipitation systems, and the application of composite radar precipitation data, including the improvement of radar precipitation data retrieval algorithms. (3) Studies on 3D storm tracking method were introduced, including the classification of storms according to different storm tracks and attributes and differences in the initiation and development mechanism of different kinds of storms.

Based on the conventional meteorological observation data, ECMWF reanalysis data and reflectivity factor data of Doppler radar, the circulation situations, weather systems configuration, dynamic and thermal conditions of an elevated thunderstorm weather process behind cold front in the central of Gansu Province from October 8 to 9, 2017 were diagnosed synthetically. The results show that the weather systems affecting the occurrence and development of the elevated thunderstorm weather were mainly cold front, 700 hPa shear line, southwestern jet and 500 hPa upper-level trough. The cold air moving southward formed a cold pad near the ground, and the warm and humid airflow climbed along cold front, which triggered the elevated thunderstorm weather at the inversion layer top near 620 hPa. The inversion layer of the elevated thunderstorm weather was deep, and there were three 0 ℃ layers in vertical direction. Under the influence of rainfall before the occurrence of the elevated thunderstorm process and southwest warm and moist airflow, the atmosphere was dry in upper layer and humid in lower layer, and it was cold in upper and lower layers and warm in middle layer, which indicated the atmospheric stratification was instability. The vertical wind shear in middle and lower levels of troposphere, convergence in lower level and divergence in upper level prompted the uplift of warm and humid air. The high energy tongue and BCAPE in middle and lower levels could reflect unstable energy conditions well during the process. During the elevated thunderstorms process, the rainfall (snowfall) and hail weather accompanying wide-range and northeast-southwest thunder and lightning appeared over Lanzhou and its surrounding. The strong echo height of radar reflectivity factor exceeded 8 km, and the echo characteristic of hail was typical.